Series comparison

-[Qemu-devel] [PULL 00/12] Block patches
+[PULL v2 00/28] Block patches
-The following changes since commit 9964e96dc9999cf7f7c936ee854a795415d19b60:
+The following changes since commit ac793156f650ae2d77834932d72224175ee69086:
-  Merge remote-tracking branch 'jasowang/tags/net-pull-request' into staging (2017-05-23 15:01:31 +0100)
+  Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20201020-1' into staging (2020-10-20 21:11:35 +0100)
-are available in the git repository at:
+are available in the Git repository at:
-  git://github.com/codyprime/qemu-kvm-jtc.git tags/block-pull-request
+  https://gitlab.com/stefanha/qemu.git tags/block-pull-request
-for you to fetch changes up to 223a23c198787328ae75bc65d84edf5fde33c0b6:
+for you to fetch changes up to 32a3fd65e7e3551337fd26bfc0e2f899d70c028c:
-  block/gluster: glfs_lseek() workaround (2017-05-24 16:44:46 -0400)
+  iotests: add commit top->base cases to 274 (2020-10-22 09:55:39 +0100)
 ----------------------------------------------------------------
-Block patches
+Pull request
 v2:
  * Fix format string issues on 32-bit hosts [Peter]
  * Fix qemu-nbd.c CONFIG_POSIX ifdef issue [Eric]
  * Fix missing eventfd.h header on macOS [Peter]
  * Drop unreliable vhost-user-blk test (will send a new patch when ready) [Peter]
 This pull request contains the vhost-user-blk server by Coiby Xu along with my
 additions, block/nvme.c alignment and hardware error statistics by Philippe
 Mathieu-Daudé, and bdrv_co_block_status_above() fixes by Vladimir
 Sementsov-Ogievskiy.
 ----------------------------------------------------------------
-Jeff Cody (1):
+Coiby Xu (6):
-  block/gluster: glfs_lseek() workaround
+  libvhost-user: Allow vu_message_read to be replaced
   libvhost-user: remove watch for kick_fd when de-initialize vu-dev
   util/vhost-user-server: generic vhost user server
   block: move logical block size check function to a common utility
     function
   block/export: vhost-user block device backend server
   MAINTAINERS: Add vhost-user block device backend server maintainer
-Paolo Bonzini (11):
+Philippe Mathieu-Daudé (1):
-  blockjob: remove unnecessary check
+  block/nvme: Add driver statistics for access alignment and hw errors
   blockjob: remove iostatus_reset callback
   blockjob: introduce block_job_early_fail
   blockjob: introduce block_job_pause/resume_all
   blockjob: separate monitor and blockjob APIs
   blockjob: move iostatus reset inside block_job_user_resume
   blockjob: introduce block_job_cancel_async, check iostatus invariants
   blockjob: group BlockJob transaction functions together
   blockjob: strengthen a bit test-blockjob-txn
   blockjob: reorganize block_job_completed_txn_abort
   blockjob: use deferred_to_main_loop to indicate the coroutine has
     ended
- block/backup.c               |   2 +-
+Stefan Hajnoczi (16):
- block/commit.c               |   2 +-
+  util/vhost-user-server: s/fileds/fields/ typo fix
- block/gluster.c              |  18 +-
+  util/vhost-user-server: drop unnecessary QOM cast
- block/io.c                   |  19 +-
+  util/vhost-user-server: drop unnecessary watch deletion
- block/mirror.c               |   2 +-
+  block/export: consolidate request structs into VuBlockReq
- blockdev.c                   |   1 -
+  util/vhost-user-server: drop unused DevicePanicNotifier
- blockjob.c                   | 750 ++++++++++++++++++++++++-------------------
+  util/vhost-user-server: fix memory leak in vu_message_read()
- include/block/blockjob.h     |  16 -
+  util/vhost-user-server: check EOF when reading payload
- include/block/blockjob_int.h |  27 +-
+  util/vhost-user-server: rework vu_client_trip() coroutine lifecycle
- tests/test-blockjob-txn.c    |   7 +-
+  block/export: report flush errors
- tests/test-blockjob.c        |  10 +-
+  block/export: convert vhost-user-blk server to block export API
-files changed, 463 insertions(+), 391 deletions(-)
+  util/vhost-user-server: move header to include/
   util/vhost-user-server: use static library in meson.build
   qemu-storage-daemon: avoid compiling blockdev_ss twice
   block: move block exports to libblockdev
   block/export: add iothread and fixed-iothread options
   block/export: add vhost-user-blk multi-queue support
 Vladimir Sementsov-Ogievskiy (5):
   block/io: fix bdrv_co_block_status_above
   block/io: bdrv_common_block_status_above: support include_base
   block/io: bdrv_common_block_status_above: support bs == base
   block/io: fix bdrv_is_allocated_above
   iotests: add commit top->base cases to 274
  MAINTAINERS                                |   9 +
  qapi/block-core.json                       |  24 +-
  qapi/block-export.json                     |  36 +-
  block/coroutines.h                         |   2 +
  block/export/vhost-user-blk-server.h       |  19 +
  contrib/libvhost-user/libvhost-user.h      |  21 +
  include/qemu/vhost-user-server.h           |  65 +++
  util/block-helpers.h                       |  19 +
  block/export/export.c                      |  37 +-
  block/export/vhost-user-blk-server.c       | 431 ++++++++++++++++++++
  block/io.c                                 | 132 +++---
  block/nvme.c                               |  27 ++
  block/qcow2.c                              |  16 +-
  contrib/libvhost-user/libvhost-user-glib.c |   2 +-
  contrib/libvhost-user/libvhost-user.c      |  15 +-
  hw/core/qdev-properties-system.c           |  31 +-
  nbd/server.c                               |   2 -
  qemu-nbd.c                                 |  21 +-
  softmmu/vl.c                               |   4 +
  stubs/blk-exp-close-all.c                  |   7 +
  tests/vhost-user-bridge.c                  |   2 +
  tools/virtiofsd/fuse_virtio.c              |   4 +-
  util/block-helpers.c                       |  46 +++
  util/vhost-user-server.c                   | 446 +++++++++++++++++++++
  block/export/meson.build                   |   3 +-
  contrib/libvhost-user/meson.build          |   1 +
  meson.build                                |  22 +-
  nbd/meson.build                            |   2 +
  storage-daemon/meson.build                 |   3 +-
  stubs/meson.build                          |   1 +
  tests/qemu-iotests/274                     |  20 +
  tests/qemu-iotests/274.out                 |  68 ++++
  util/meson.build                           |   4 +
 files changed, 1420 insertions(+), 122 deletions(-)
  create mode 100644 block/export/vhost-user-blk-server.h
  create mode 100644 include/qemu/vhost-user-server.h
  create mode 100644 util/block-helpers.h
  create mode 100644 block/export/vhost-user-blk-server.c
  create mode 100644 stubs/blk-exp-close-all.c
  create mode 100644 util/block-helpers.c
  create mode 100644 util/vhost-user-server.c
 --
-.9.3
+.26.2

-[Qemu-devel] [PULL 03/12] blockjob: introduce block_job_early_fail
+[PULL v2 01/28] block/nvme: Add driver statistics for access alignment and hw errors
-From: Paolo Bonzini <pbonzini@redhat.com>
+From: Philippe Mathieu-Daudé <philmd@redhat.com>
-Outside blockjob.c, block_job_unref is only used when a block job fails
+Keep statistics of some hardware errors, and number of
-to start, and block_job_ref is not used at all.  The reference counting
+aligned/unaligned I/O accesses.
 thus is pretty well hidden.  Introduce a separate function to be used
 by block jobs; because block_job_ref and block_job_unref now become
 static, move them earlier in blockjob.c.
-Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+QMP example booting a full RHEL 8.3 aarch64 guest:
-Reviewed-by: John Snow <jsnow@redhat.com>
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+{ "execute": "query-blockstats" }
-Reviewed-by: Jeff Cody <jcody@redhat.com>
+{
-Message-id: 20170508141310.8674-4-pbonzini@redhat.com
+    "return": [
-Signed-off-by: Jeff Cody <jcody@redhat.com>
+        {
             "device": "",
             "node-name": "drive0",
             "stats": {
                 "flush_total_time_ns": 6026948,
                 "wr_highest_offset": 3383991230464,
                 "wr_total_time_ns": 807450995,
                 "failed_wr_operations": 0,
                 "failed_rd_operations": 0,
                 "wr_merged": 3,
                 "wr_bytes": 50133504,
                 "failed_unmap_operations": 0,
                 "failed_flush_operations": 0,
                 "account_invalid": false,
                 "rd_total_time_ns": 1846979900,
                 "flush_operations": 130,
                 "wr_operations": 659,
                 "rd_merged": 1192,
                 "rd_bytes": 218244096,
                 "account_failed": false,
                 "idle_time_ns": 2678641497,
                 "rd_operations": 7406,
             },
             "driver-specific": {
                 "driver": "nvme",
                 "completion-errors": 0,
                 "unaligned-accesses": 2959,
                 "aligned-accesses": 4477
             },
             "qdev": "/machine/peripheral-anon/device[0]/virtio-backend"
         }
     ]
 }
 Suggested-by: Stefan Hajnoczi <stefanha@gmail.com>
 Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
 Acked-by: Markus Armbruster <armbru@redhat.com>
 Message-id: 20201001162939.1567915-1-philmd@redhat.com
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
- block/backup.c               |  2 +-
+ qapi/block-core.json | 24 +++++++++++++++++++++++-
- block/commit.c               |  2 +-
+ block/nvme.c         | 27 +++++++++++++++++++++++++++
- block/mirror.c               |  2 +-
+files changed, 50 insertions(+), 1 deletion(-)
  blockjob.c                   | 47 ++++++++++++++++++++++++++------------------
  include/block/blockjob_int.h | 15 +++-----------
  tests/test-blockjob.c        | 10 +++++-----
 files changed, 39 insertions(+), 39 deletions(-)
-diff --git a/block/backup.c b/block/backup.c
+diff --git a/qapi/block-core.json b/qapi/block-core.json
 index XXXXXXX..XXXXXXX 100644
---- a/block/backup.c
+--- a/qapi/block-core.json
-+++ b/block/backup.c
++++ b/qapi/block-core.json
-@@ -XXX,XX +XXX,XX @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
+@@ -XXX,XX +XXX,XX @@
        'discard-nb-failed': 'uint64',
        'discard-bytes-ok': 'uint64' } }
 +##
 +# @BlockStatsSpecificNvme:
 +#
 +# NVMe driver statistics
 +#
 +# @completion-errors: The number of completion errors.
 +#
 +# @aligned-accesses: The number of aligned accesses performed by
 +#                    the driver.
 +#
 +# @unaligned-accesses: The number of unaligned accesses performed by
 +#                      the driver.
 +#
 +# Since: 5.2
 +##
 +{ 'struct': 'BlockStatsSpecificNvme',
 +  'data': {
 +      'completion-errors': 'uint64',
 +      'aligned-accesses': 'uint64',
 +      'unaligned-accesses': 'uint64' } }
 +
  ##
  # @BlockStatsSpecific:
  #
@@ -XXX,XX +XXX,XX @@
    'discriminator': 'driver',
    'data': {
        'file': 'BlockStatsSpecificFile',
 -      'host_device': 'BlockStatsSpecificFile' } }
 +      'host_device': 'BlockStatsSpecificFile',
 +      'nvme': 'BlockStatsSpecificNvme' } }
  ##
  # @BlockStats:
 diff --git a/block/nvme.c b/block/nvme.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/nvme.c
 +++ b/block/nvme.c
@@ -XXX,XX +XXX,XX @@ struct BDRVNVMeState {
      /* PCI address (required for nvme_refresh_filename()) */
      char *device;
 +
 +    struct {
 +        uint64_t completion_errors;
 +        uint64_t aligned_accesses;
 +        uint64_t unaligned_accesses;
 +    } stats;
  };
  #define NVME_BLOCK_OPT_DEVICE "device"
@@ -XXX,XX +XXX,XX @@ static bool nvme_process_completion(NVMeQueuePair *q)
              break;
          }
          ret = nvme_translate_error(c);
 +        if (ret) {
 +            s->stats.completion_errors++;
 +        }
          q->cq.head = (q->cq.head + 1) % NVME_QUEUE_SIZE;
          if (!q->cq.head) {
              q->cq_phase = !q->cq_phase;
@@ -XXX,XX +XXX,XX @@ static int nvme_co_prw(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
      assert(QEMU_IS_ALIGNED(bytes, s->page_size));
      assert(bytes <= s->max_transfer);
      if (nvme_qiov_aligned(bs, qiov)) {
 +        s->stats.aligned_accesses++;
          return nvme_co_prw_aligned(bs, offset, bytes, qiov, is_write, flags);
      }
-     if (job) {
++    s->stats.unaligned_accesses++;
-         backup_clean(&job->common);
+     trace_nvme_prw_buffered(s, offset, bytes, qiov->niov, is_write);
--        block_job_unref(&job->common);
+     buf = qemu_try_memalign(s->page_size, bytes);
-+        block_job_early_fail(&job->common);
-     }
+@@ -XXX,XX +XXX,XX @@ static void nvme_unregister_buf(BlockDriverState *bs, void *host)
+     qemu_vfio_dma_unmap(s->vfio, host);
      return NULL;
 diff --git a/block/commit.c b/block/commit.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/commit.c
 +++ b/block/commit.c
@@ -XXX,XX +XXX,XX @@ fail:
      if (commit_top_bs) {
          bdrv_set_backing_hd(overlay_bs, top, &error_abort);
      }
 -    block_job_unref(&s->common);
 +    block_job_early_fail(&s->common);
  }
++static BlockStatsSpecific *nvme_get_specific_stats(BlockDriverState *bs)
 diff --git a/block/mirror.c b/block/mirror.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/mirror.c
 +++ b/block/mirror.c
@@ -XXX,XX +XXX,XX @@ fail:
          g_free(s->replaces);
          blk_unref(s->target);
 -        block_job_unref(&s->common);
 +        block_job_early_fail(&s->common);
      }
      bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL,
 diff --git a/blockjob.c b/blockjob.c
 index XXXXXXX..XXXXXXX 100644
 --- a/blockjob.c
 +++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ BlockJob *block_job_get(const char *id)
      return NULL;
  }
 +static void block_job_ref(BlockJob *job)
 +{
-+    ++job->refcnt;
++    BlockStatsSpecific *stats = g_new(BlockStatsSpecific, 1);
 +    BDRVNVMeState *s = bs->opaque;
 +
 +    stats->driver = BLOCKDEV_DRIVER_NVME;
 +    stats->u.nvme = (BlockStatsSpecificNvme) {
 +        .completion_errors = s->stats.completion_errors,
 +        .aligned_accesses = s->stats.aligned_accesses,
 +        .unaligned_accesses = s->stats.unaligned_accesses,
 +    };
 +
 +    return stats;
 +}
 +
-+static void block_job_attached_aio_context(AioContext *new_context,
+ static const char *const nvme_strong_runtime_opts[] = {
-+                                           void *opaque);
+     NVME_BLOCK_OPT_DEVICE,
-+static void block_job_detach_aio_context(void *opaque);
+     NVME_BLOCK_OPT_NAMESPACE,
-+
+@@ -XXX,XX +XXX,XX @@ static BlockDriver bdrv_nvme = {
-+static void block_job_unref(BlockJob *job)
+     .bdrv_refresh_filename    = nvme_refresh_filename,
-+{
+     .bdrv_refresh_limits      = nvme_refresh_limits,
-+    if (--job->refcnt == 0) {
+     .strong_runtime_opts      = nvme_strong_runtime_opts,
-+        BlockDriverState *bs = blk_bs(job->blk);
++    .bdrv_get_specific_stats  = nvme_get_specific_stats,
-+        bs->job = NULL;
-+        block_job_remove_all_bdrv(job);
+     .bdrv_detach_aio_context  = nvme_detach_aio_context,
-+        blk_remove_aio_context_notifier(job->blk,
+     .bdrv_attach_aio_context  = nvme_attach_aio_context,
 +                                        block_job_attached_aio_context,
 +                                        block_job_detach_aio_context, job);
 +        blk_unref(job->blk);
 +        error_free(job->blocker);
 +        g_free(job->id);
 +        QLIST_REMOVE(job, job_list);
 +        g_free(job);
 +    }
 +}
 +
  static void block_job_attached_aio_context(AioContext *new_context,
                                             void *opaque)
  {
@@ -XXX,XX +XXX,XX @@ void block_job_start(BlockJob *job)
      bdrv_coroutine_enter(blk_bs(job->blk), job->co);
  }
 -void block_job_ref(BlockJob *job)
 +void block_job_early_fail(BlockJob *job)
  {
 -    ++job->refcnt;
 -}
 -
 -void block_job_unref(BlockJob *job)
 -{
 -    if (--job->refcnt == 0) {
 -        BlockDriverState *bs = blk_bs(job->blk);
 -        bs->job = NULL;
 -        block_job_remove_all_bdrv(job);
 -        blk_remove_aio_context_notifier(job->blk,
 -                                        block_job_attached_aio_context,
 -                                        block_job_detach_aio_context, job);
 -        blk_unref(job->blk);
 -        error_free(job->blocker);
 -        g_free(job->id);
 -        QLIST_REMOVE(job, job_list);
 -        g_free(job);
 -    }
 +    block_job_unref(job);
  }
  static void block_job_completed_single(BlockJob *job)
 diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/block/blockjob_int.h
 +++ b/include/block/blockjob_int.h
@@ -XXX,XX +XXX,XX @@ void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns);
  void block_job_yield(BlockJob *job);
  /**
 - * block_job_ref:
 + * block_job_early_fail:
   * @bs: The block device.
   *
 - * Grab a reference to the block job. Should be paired with block_job_unref.
 + * The block job could not be started, free it.
   */
 -void block_job_ref(BlockJob *job);
 -
 -/**
 - * block_job_unref:
 - * @bs: The block device.
 - *
 - * Release reference to the block job and release resources if it is the last
 - * reference.
 - */
 -void block_job_unref(BlockJob *job);
 +void block_job_early_fail(BlockJob *job);
  /**
   * block_job_completed:
 diff --git a/tests/test-blockjob.c b/tests/test-blockjob.c
 index XXXXXXX..XXXXXXX 100644
 --- a/tests/test-blockjob.c
 +++ b/tests/test-blockjob.c
@@ -XXX,XX +XXX,XX @@ static void test_job_ids(void)
      job[1] = do_test_id(blk[1], "id0", false);
      /* But once job[0] finishes we can reuse its ID */
 -    block_job_unref(job[0]);
 +    block_job_early_fail(job[0]);
      job[1] = do_test_id(blk[1], "id0", true);
      /* No job ID specified, defaults to the backend name ('drive1') */
 -    block_job_unref(job[1]);
 +    block_job_early_fail(job[1]);
      job[1] = do_test_id(blk[1], NULL, true);
      /* Duplicate job ID */
@@ -XXX,XX +XXX,XX @@ static void test_job_ids(void)
      /* This one is valid */
      job[2] = do_test_id(blk[2], "id_2", true);
 -    block_job_unref(job[0]);
 -    block_job_unref(job[1]);
 -    block_job_unref(job[2]);
 +    block_job_early_fail(job[0]);
 +    block_job_early_fail(job[1]);
 +    block_job_early_fail(job[2]);
      destroy_blk(blk[0]);
      destroy_blk(blk[1]);
 --
-.9.3
+.26.2

-[Qemu-devel] [PULL 09/12] blockjob: strengthen a bit test-blockjob-txn
+[PULL v2 02/28] libvhost-user: Allow vu_message_read to be replaced
-From: Paolo Bonzini <pbonzini@redhat.com>
+From: Coiby Xu <coiby.xu@gmail.com>
-Unlike test-blockjob-txn, QMP releases the reference to the transaction
+Allow vu_message_read to be replaced by one which will make use of the
-before the jobs finish.  Thus, qemu-iotest 124 showed a failure while
+QIOChannel functions. Thus reading vhost-user message won't stall the
-working on the next patch that the unit tests did not have.  Make
+guest. For slave channel, we still use the default vu_message_read.
 the test a little nastier.
+Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
+Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
 Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
-Reviewed-by: John Snow <jsnow@redhat.com>
+Message-id: 20200918080912.321299-2-coiby.xu@gmail.com
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 Message-id: 20170508141310.8674-10-pbonzini@redhat.com
 Signed-off-by: Jeff Cody <jcody@redhat.com>
 ---
- tests/test-blockjob-txn.c | 7 +++++--
+ contrib/libvhost-user/libvhost-user.h      | 21 +++++++++++++++++++++
-file changed, 5 insertions(+), 2 deletions(-)
+ contrib/libvhost-user/libvhost-user-glib.c |  2 +-
  contrib/libvhost-user/libvhost-user.c      | 14 +++++++-------
  tests/vhost-user-bridge.c                  |  2 ++
  tools/virtiofsd/fuse_virtio.c              |  4 ++--
 files changed, 33 insertions(+), 10 deletions(-)
-diff --git a/tests/test-blockjob-txn.c b/tests/test-blockjob-txn.c
+diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h
 index XXXXXXX..XXXXXXX 100644
---- a/tests/test-blockjob-txn.c
+--- a/contrib/libvhost-user/libvhost-user.h
-+++ b/tests/test-blockjob-txn.c
++++ b/contrib/libvhost-user/libvhost-user.h
-@@ -XXX,XX +XXX,XX @@ static void test_pair_jobs(int expected1, int expected2)
+@@ -XXX,XX +XXX,XX @@
-     block_job_start(job1);
+  */
-     block_job_start(job2);
+ #define VHOST_USER_MAX_RAM_SLOTS 32
-+    /* Release our reference now to trigger as many nice
++#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
-+     * use-after-free bugs as possible.
++
  typedef enum VhostSetConfigType {
      VHOST_SET_CONFIG_TYPE_MASTER = 0,
      VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
@@ -XXX,XX +XXX,XX @@ typedef uint64_t (*vu_get_features_cb) (VuDev *dev);
  typedef void (*vu_set_features_cb) (VuDev *dev, uint64_t features);
  typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg,
                                    int *do_reply);
 +typedef bool (*vu_read_msg_cb) (VuDev *dev, int sock, VhostUserMsg *vmsg);
  typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool started);
  typedef bool (*vu_queue_is_processed_in_order_cb) (VuDev *dev, int qidx);
  typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, uint32_t len);
@@ -XXX,XX +XXX,XX @@ struct VuDev {
      bool broken;
      uint16_t max_queues;
 +    /* @read_msg: custom method to read vhost-user message
 +     *
 +     * Read data from vhost_user socket fd and fill up
 +     * the passed VhostUserMsg *vmsg struct.
 +     *
 +     * If reading fails, it should close the received set of file
 +     * descriptors as socket message's auxiliary data.
 +     *
 +     * For the details, please refer to vu_message_read in libvhost-user.c
 +     * which will be used by default if not custom method is provided when
 +     * calling vu_init
 +     *
 +     * Returns: true if vhost-user message successfully received,
 +     *          otherwise return false.
 +     *
 +     */
-+    block_job_txn_unref(txn);
++    vu_read_msg_cb read_msg;
-+
+     /* @set_watch: add or update the given fd to the watch set,
-     if (expected1 == -ECANCELED) {
+      * call cb when condition is met */
-         block_job_cancel(job1);
+     vu_set_watch_cb set_watch;
@@ -XXX,XX +XXX,XX @@ bool vu_init(VuDev *dev,
               uint16_t max_queues,
               int socket,
               vu_panic_cb panic,
 +             vu_read_msg_cb read_msg,
               vu_set_watch_cb set_watch,
               vu_remove_watch_cb remove_watch,
               const VuDevIface *iface);
 diff --git a/contrib/libvhost-user/libvhost-user-glib.c b/contrib/libvhost-user/libvhost-user-glib.c
 index XXXXXXX..XXXXXXX 100644
 --- a/contrib/libvhost-user/libvhost-user-glib.c
 +++ b/contrib/libvhost-user/libvhost-user-glib.c
@@ -XXX,XX +XXX,XX @@ vug_init(VugDev *dev, uint16_t max_queues, int socket,
      g_assert(dev);
      g_assert(iface);
 -    if (!vu_init(&dev->parent, max_queues, socket, panic, set_watch,
 +    if (!vu_init(&dev->parent, max_queues, socket, panic, NULL, set_watch,
                   remove_watch, iface)) {
          return false;
      }
-@@ -XXX,XX +XXX,XX @@ static void test_pair_jobs(int expected1, int expected2)
+diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
+index XXXXXXX..XXXXXXX 100644
-     g_assert_cmpint(result1, ==, expected1);
+--- a/contrib/libvhost-user/libvhost-user.c
-     g_assert_cmpint(result2, ==, expected2);
++++ b/contrib/libvhost-user/libvhost-user.c
@@ -XXX,XX +XXX,XX @@
  /* The version of inflight buffer */
  #define INFLIGHT_VERSION 1
 -#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
 -
--    block_job_txn_unref(txn);
+ /* The version of the protocol we support */
  #define VHOST_USER_VERSION 1
  #define LIBVHOST_USER_DEBUG 0
@@ -XXX,XX +XXX,XX @@ have_userfault(void)
  }
- static void test_pair_jobs_success(void)
+ static bool
 -vu_message_read(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
 +vu_message_read_default(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
  {
      char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS * sizeof(int))] = {};
      struct iovec iov = {
@@ -XXX,XX +XXX,XX @@ vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg)
          goto out;
      }
 -    if (!vu_message_read(dev, dev->slave_fd, &msg_reply)) {
 +    if (!vu_message_read_default(dev, dev->slave_fd, &msg_reply)) {
          goto out;
      }
@@ -XXX,XX +XXX,XX @@ vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg)
      /* Wait for QEMU to confirm that it's registered the handler for the
       * faults.
       */
 -    if (!vu_message_read(dev, dev->sock, vmsg) ||
 +    if (!dev->read_msg(dev, dev->sock, vmsg) ||
          vmsg->size != sizeof(vmsg->payload.u64) ||
          vmsg->payload.u64 != 0) {
          vu_panic(dev, "failed to receive valid ack for postcopy set-mem-table");
@@ -XXX,XX +XXX,XX @@ vu_dispatch(VuDev *dev)
      int reply_requested;
      bool need_reply, success = false;
 -    if (!vu_message_read(dev, dev->sock, &vmsg)) {
 +    if (!dev->read_msg(dev, dev->sock, &vmsg)) {
          goto end;
      }
@@ -XXX,XX +XXX,XX @@ vu_init(VuDev *dev,
          uint16_t max_queues,
          int socket,
          vu_panic_cb panic,
 +        vu_read_msg_cb read_msg,
          vu_set_watch_cb set_watch,
          vu_remove_watch_cb remove_watch,
          const VuDevIface *iface)
@@ -XXX,XX +XXX,XX @@ vu_init(VuDev *dev,
      dev->sock = socket;
      dev->panic = panic;
 +    dev->read_msg = read_msg ? read_msg : vu_message_read_default;
      dev->set_watch = set_watch;
      dev->remove_watch = remove_watch;
      dev->iface = iface;
@@ -XXX,XX +XXX,XX @@ static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync)
          vu_message_write(dev, dev->slave_fd, &vmsg);
          if (ack) {
 -            vu_message_read(dev, dev->slave_fd, &vmsg);
 +            vu_message_read_default(dev, dev->slave_fd, &vmsg);
          }
          return;
      }
 diff --git a/tests/vhost-user-bridge.c b/tests/vhost-user-bridge.c
 index XXXXXXX..XXXXXXX 100644
 --- a/tests/vhost-user-bridge.c
 +++ b/tests/vhost-user-bridge.c
@@ -XXX,XX +XXX,XX @@ vubr_accept_cb(int sock, void *ctx)
                   VHOST_USER_BRIDGE_MAX_QUEUES,
                   conn_fd,
                   vubr_panic,
 +                 NULL,
                   vubr_set_watch,
                   vubr_remove_watch,
                   &vuiface)) {
@@ -XXX,XX +XXX,XX @@ vubr_new(const char *path, bool client)
                       VHOST_USER_BRIDGE_MAX_QUEUES,
                       dev->sock,
                       vubr_panic,
 +                     NULL,
                       vubr_set_watch,
                       vubr_remove_watch,
                       &vuiface)) {
 diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c
 index XXXXXXX..XXXXXXX 100644
 --- a/tools/virtiofsd/fuse_virtio.c
 +++ b/tools/virtiofsd/fuse_virtio.c
@@ -XXX,XX +XXX,XX @@ int virtio_session_mount(struct fuse_session *se)
      se->vu_socketfd = data_sock;
      se->virtio_dev->se = se;
      pthread_rwlock_init(&se->virtio_dev->vu_dispatch_rwlock, NULL);
 -    vu_init(&se->virtio_dev->dev, 2, se->vu_socketfd, fv_panic, fv_set_watch,
 -            fv_remove_watch, &fv_iface);
 +    vu_init(&se->virtio_dev->dev, 2, se->vu_socketfd, fv_panic, NULL,
 +            fv_set_watch, fv_remove_watch, &fv_iface);
      return 0;
  }
 --
-.9.3
+.26.2

-New patch
+[PULL v2 03/28] libvhost-user: remove watch for kick_fd when de-initialize vu-dev
+From: Coiby Xu <coiby.xu@gmail.com>
+When the client is running in gdb and quit command is run in gdb,
+QEMU will still dispatch the event which will cause segment fault in
+the callback function.
+Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
+Message-id: 20200918080912.321299-3-coiby.xu@gmail.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ contrib/libvhost-user/libvhost-user.c | 1 +
+file changed, 1 insertion(+)
+diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
+index XXXXXXX..XXXXXXX 100644
+--- a/contrib/libvhost-user/libvhost-user.c
++++ b/contrib/libvhost-user/libvhost-user.c
+@@ -XXX,XX +XXX,XX @@ vu_deinit(VuDev *dev)
+         }
+         if (vq->kick_fd != -1) {
++            dev->remove_watch(dev, vq->kick_fd);
+             close(vq->kick_fd);
+             vq->kick_fd = -1;
+         }
+--
+.26.2

-New patch
+[PULL v2 04/28] util/vhost-user-server: generic vhost user server
+From: Coiby Xu <coiby.xu@gmail.com>
+Sharing QEMU devices via vhost-user protocol.
+Only one vhost-user client can connect to the server one time.
+Suggested-by: Kevin Wolf <kwolf@redhat.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
+Message-id: 20200918080912.321299-4-coiby.xu@gmail.com
+[Fixed size_t %lu -> %zu format string compiler error.
+--Stefan]
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ util/vhost-user-server.h |  65 ++++++
+ util/vhost-user-server.c | 428 +++++++++++++++++++++++++++++++++++++++
+ util/meson.build         |   1 +
+files changed, 494 insertions(+)
+ create mode 100644 util/vhost-user-server.h
+ create mode 100644 util/vhost-user-server.c
+diff --git a/util/vhost-user-server.h b/util/vhost-user-server.h
+new file mode 100644
+index XXXXXXX..XXXXXXX
+--- /dev/null
++++ b/util/vhost-user-server.h
+@@ -XXX,XX +XXX,XX @@
++/*
++ * Sharing QEMU devices via vhost-user protocol
++ *
++ * Copyright (c) Coiby Xu <coiby.xu@gmail.com>.
++ * Copyright (c) 2020 Red Hat, Inc.
++ *
++ * This work is licensed under the terms of the GNU GPL, version 2 or
++ * later.  See the COPYING file in the top-level directory.
++ */
++
++#ifndef VHOST_USER_SERVER_H
++#define VHOST_USER_SERVER_H
++
++#include "contrib/libvhost-user/libvhost-user.h"
++#include "io/channel-socket.h"
++#include "io/channel-file.h"
++#include "io/net-listener.h"
++#include "qemu/error-report.h"
++#include "qapi/error.h"
++#include "standard-headers/linux/virtio_blk.h"
++
++typedef struct VuFdWatch {
++    VuDev *vu_dev;
++    int fd; /*kick fd*/
++    void *pvt;
++    vu_watch_cb cb;
++    bool processing;
++    QTAILQ_ENTRY(VuFdWatch) next;
++} VuFdWatch;
++
++typedef struct VuServer VuServer;
++typedef void DevicePanicNotifierFn(VuServer *server);
++
++struct VuServer {
++    QIONetListener *listener;
++    AioContext *ctx;
++    DevicePanicNotifierFn *device_panic_notifier;
++    int max_queues;
++    const VuDevIface *vu_iface;
++    VuDev vu_dev;
++    QIOChannel *ioc; /* The I/O channel with the client */
++    QIOChannelSocket *sioc; /* The underlying data channel with the client */
++    /* IOChannel for fd provided via VHOST_USER_SET_SLAVE_REQ_FD */
++    QIOChannel *ioc_slave;
++    QIOChannelSocket *sioc_slave;
++    Coroutine *co_trip; /* coroutine for processing VhostUserMsg */
++    QTAILQ_HEAD(, VuFdWatch) vu_fd_watches;
++    /* restart coroutine co_trip if AIOContext is changed */
++    bool aio_context_changed;
++    bool processing_msg;
++};
++
++bool vhost_user_server_start(VuServer *server,
++                             SocketAddress *unix_socket,
++                             AioContext *ctx,
++                             uint16_t max_queues,
++                             DevicePanicNotifierFn *device_panic_notifier,
++                             const VuDevIface *vu_iface,
++                             Error **errp);
++
++void vhost_user_server_stop(VuServer *server);
++
++void vhost_user_server_set_aio_context(VuServer *server, AioContext *ctx);
++
++#endif /* VHOST_USER_SERVER_H */
+diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
+new file mode 100644
+index XXXXXXX..XXXXXXX
+--- /dev/null
++++ b/util/vhost-user-server.c
+@@ -XXX,XX +XXX,XX @@
++/*
++ * Sharing QEMU devices via vhost-user protocol
++ *
++ * Copyright (c) Coiby Xu <coiby.xu@gmail.com>.
++ * Copyright (c) 2020 Red Hat, Inc.
++ *
++ * This work is licensed under the terms of the GNU GPL, version 2 or
++ * later.  See the COPYING file in the top-level directory.
++ */
++#include "qemu/osdep.h"
++#include "qemu/main-loop.h"
++#include "vhost-user-server.h"
++
++static void vmsg_close_fds(VhostUserMsg *vmsg)
++{
++    int i;
++    for (i = 0; i < vmsg->fd_num; i++) {
++        close(vmsg->fds[i]);
++    }
++}
++
++static void vmsg_unblock_fds(VhostUserMsg *vmsg)
++{
++    int i;
++    for (i = 0; i < vmsg->fd_num; i++) {
++        qemu_set_nonblock(vmsg->fds[i]);
++    }
++}
++
++static void vu_accept(QIONetListener *listener, QIOChannelSocket *sioc,
++                      gpointer opaque);
++
++static void close_client(VuServer *server)
++{
++    /*
++     * Before closing the client
++     *
++     * 1. Let vu_client_trip stop processing new vhost-user msg
++     *
++     * 2. remove kick_handler
++     *
++     * 3. wait for the kick handler to be finished
++     *
++     * 4. wait for the current vhost-user msg to be finished processing
++     */
++
++    QIOChannelSocket *sioc = server->sioc;
++    /* When this is set vu_client_trip will stop new processing vhost-user message */
++    server->sioc = NULL;
++
++    VuFdWatch *vu_fd_watch, *next;
++    QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
++        aio_set_fd_handler(server->ioc->ctx, vu_fd_watch->fd, true, NULL,
++                           NULL, NULL, NULL);
++    }
++
++    while (!QTAILQ_EMPTY(&server->vu_fd_watches)) {
++        QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
++            if (!vu_fd_watch->processing) {
++                QTAILQ_REMOVE(&server->vu_fd_watches, vu_fd_watch, next);
++                g_free(vu_fd_watch);
++            }
++        }
++    }
++
++    while (server->processing_msg) {
++        if (server->ioc->read_coroutine) {
++            server->ioc->read_coroutine = NULL;
++            qio_channel_set_aio_fd_handler(server->ioc, server->ioc->ctx, NULL,
++                                           NULL, server->ioc);
++            server->processing_msg = false;
++        }
++    }
++
++    vu_deinit(&server->vu_dev);
++    object_unref(OBJECT(sioc));
++    object_unref(OBJECT(server->ioc));
++}
++
++static void panic_cb(VuDev *vu_dev, const char *buf)
++{
++    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
++
++    /* avoid while loop in close_client */
++    server->processing_msg = false;
++
++    if (buf) {
++        error_report("vu_panic: %s", buf);
++    }
++
++    if (server->sioc) {
++        close_client(server);
++    }
++
++    if (server->device_panic_notifier) {
++        server->device_panic_notifier(server);
++    }
++
++    /*
++     * Set the callback function for network listener so another
++     * vhost-user client can connect to this server
++     */
++    qio_net_listener_set_client_func(server->listener,
++                                     vu_accept,
++                                     server,
++                                     NULL);
++}
++
++static bool coroutine_fn
++vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg *vmsg)
++{
++    struct iovec iov = {
++        .iov_base = (char *)vmsg,
++        .iov_len = VHOST_USER_HDR_SIZE,
++    };
++    int rc, read_bytes = 0;
++    Error *local_err = NULL;
++    /*
++     * Store fds/nfds returned from qio_channel_readv_full into
++     * temporary variables.
++     *
++     * VhostUserMsg is a packed structure, gcc will complain about passing
++     * pointer to a packed structure member if we pass &VhostUserMsg.fd_num
++     * and &VhostUserMsg.fds directly when calling qio_channel_readv_full,
++     * thus two temporary variables nfds and fds are used here.
++     */
++    size_t nfds = 0, nfds_t = 0;
++    const size_t max_fds = G_N_ELEMENTS(vmsg->fds);
++    int *fds_t = NULL;
++    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
++    QIOChannel *ioc = server->ioc;
++
++    if (!ioc) {
++        error_report_err(local_err);
++        goto fail;
++    }
++
++    assert(qemu_in_coroutine());
++    do {
++        /*
++         * qio_channel_readv_full may have short reads, keeping calling it
++         * until getting VHOST_USER_HDR_SIZE or 0 bytes in total
++         */
++        rc = qio_channel_readv_full(ioc, &iov, 1, &fds_t, &nfds_t, &local_err);
++        if (rc < 0) {
++            if (rc == QIO_CHANNEL_ERR_BLOCK) {
++                qio_channel_yield(ioc, G_IO_IN);
++                continue;
++            } else {
++                error_report_err(local_err);
++                return false;
++            }
++        }
++        read_bytes += rc;
++        if (nfds_t > 0) {
++            if (nfds + nfds_t > max_fds) {
++                error_report("A maximum of %zu fds are allowed, "
++                             "however got %zu fds now",
++                             max_fds, nfds + nfds_t);
++                goto fail;
++            }
++            memcpy(vmsg->fds + nfds, fds_t,
++                   nfds_t *sizeof(vmsg->fds[0]));
++            nfds += nfds_t;
++            g_free(fds_t);
++        }
++        if (read_bytes == VHOST_USER_HDR_SIZE || rc == 0) {
++            break;
++        }
++        iov.iov_base = (char *)vmsg + read_bytes;
++        iov.iov_len = VHOST_USER_HDR_SIZE - read_bytes;
++    } while (true);
++
++    vmsg->fd_num = nfds;
++    /* qio_channel_readv_full will make socket fds blocking, unblock them */
++    vmsg_unblock_fds(vmsg);
++    if (vmsg->size > sizeof(vmsg->payload)) {
++        error_report("Error: too big message request: %d, "
++                     "size: vmsg->size: %u, "
++                     "while sizeof(vmsg->payload) = %zu",
++                     vmsg->request, vmsg->size, sizeof(vmsg->payload));
++        goto fail;
++    }
++
++    struct iovec iov_payload = {
++        .iov_base = (char *)&vmsg->payload,
++        .iov_len = vmsg->size,
++    };
++    if (vmsg->size) {
++        rc = qio_channel_readv_all_eof(ioc, &iov_payload, 1, &local_err);
++        if (rc == -1) {
++            error_report_err(local_err);
++            goto fail;
++        }
++    }
++
++    return true;
++
++fail:
++    vmsg_close_fds(vmsg);
++
++    return false;
++}
++
++
++static void vu_client_start(VuServer *server);
++static coroutine_fn void vu_client_trip(void *opaque)
++{
++    VuServer *server = opaque;
++
++    while (!server->aio_context_changed && server->sioc) {
++        server->processing_msg = true;
++        vu_dispatch(&server->vu_dev);
++        server->processing_msg = false;
++    }
++
++    if (server->aio_context_changed && server->sioc) {
++        server->aio_context_changed = false;
++        vu_client_start(server);
++    }
++}
++
++static void vu_client_start(VuServer *server)
++{
++    server->co_trip = qemu_coroutine_create(vu_client_trip, server);
++    aio_co_enter(server->ctx, server->co_trip);
++}
++
++/*
++ * a wrapper for vu_kick_cb
++ *
++ * since aio_dispatch can only pass one user data pointer to the
++ * callback function, pack VuDev and pvt into a struct. Then unpack it
++ * and pass them to vu_kick_cb
++ */
++static void kick_handler(void *opaque)
++{
++    VuFdWatch *vu_fd_watch = opaque;
++    vu_fd_watch->processing = true;
++    vu_fd_watch->cb(vu_fd_watch->vu_dev, 0, vu_fd_watch->pvt);
++    vu_fd_watch->processing = false;
++}
++
++
++static VuFdWatch *find_vu_fd_watch(VuServer *server, int fd)
++{
++
++    VuFdWatch *vu_fd_watch, *next;
++    QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
++        if (vu_fd_watch->fd == fd) {
++            return vu_fd_watch;
++        }
++    }
++    return NULL;
++}
++
++static void
++set_watch(VuDev *vu_dev, int fd, int vu_evt,
++          vu_watch_cb cb, void *pvt)
++{
++
++    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
++    g_assert(vu_dev);
++    g_assert(fd >= 0);
++    g_assert(cb);
++
++    VuFdWatch *vu_fd_watch = find_vu_fd_watch(server, fd);
++
++    if (!vu_fd_watch) {
++        VuFdWatch *vu_fd_watch = g_new0(VuFdWatch, 1);
++
++        QTAILQ_INSERT_TAIL(&server->vu_fd_watches, vu_fd_watch, next);
++
++        vu_fd_watch->fd = fd;
++        vu_fd_watch->cb = cb;
++        qemu_set_nonblock(fd);
++        aio_set_fd_handler(server->ioc->ctx, fd, true, kick_handler,
++                           NULL, NULL, vu_fd_watch);
++        vu_fd_watch->vu_dev = vu_dev;
++        vu_fd_watch->pvt = pvt;
++    }
++}
++
++
++static void remove_watch(VuDev *vu_dev, int fd)
++{
++    VuServer *server;
++    g_assert(vu_dev);
++    g_assert(fd >= 0);
++
++    server = container_of(vu_dev, VuServer, vu_dev);
++
++    VuFdWatch *vu_fd_watch = find_vu_fd_watch(server, fd);
++
++    if (!vu_fd_watch) {
++        return;
++    }
++    aio_set_fd_handler(server->ioc->ctx, fd, true, NULL, NULL, NULL, NULL);
++
++    QTAILQ_REMOVE(&server->vu_fd_watches, vu_fd_watch, next);
++    g_free(vu_fd_watch);
++}
++
++
++static void vu_accept(QIONetListener *listener, QIOChannelSocket *sioc,
++                      gpointer opaque)
++{
++    VuServer *server = opaque;
++
++    if (server->sioc) {
++        warn_report("Only one vhost-user client is allowed to "
++                    "connect the server one time");
++        return;
++    }
++
++    if (!vu_init(&server->vu_dev, server->max_queues, sioc->fd, panic_cb,
++                 vu_message_read, set_watch, remove_watch, server->vu_iface)) {
++        error_report("Failed to initialize libvhost-user");
++        return;
++    }
++
++    /*
++     * Unset the callback function for network listener to make another
++     * vhost-user client keeping waiting until this client disconnects
++     */
++    qio_net_listener_set_client_func(server->listener,
++                                     NULL,
++                                     NULL,
++                                     NULL);
++    server->sioc = sioc;
++    /*
++     * Increase the object reference, so sioc will not freed by
++     * qio_net_listener_channel_func which will call object_unref(OBJECT(sioc))
++     */
++    object_ref(OBJECT(server->sioc));
++    qio_channel_set_name(QIO_CHANNEL(sioc), "vhost-user client");
++    server->ioc = QIO_CHANNEL(sioc);
++    object_ref(OBJECT(server->ioc));
++    qio_channel_attach_aio_context(server->ioc, server->ctx);
++    qio_channel_set_blocking(QIO_CHANNEL(server->sioc), false, NULL);
++    vu_client_start(server);
++}
++
++
++void vhost_user_server_stop(VuServer *server)
++{
++    if (server->sioc) {
++        close_client(server);
++    }
++
++    if (server->listener) {
++        qio_net_listener_disconnect(server->listener);
++        object_unref(OBJECT(server->listener));
++    }
++
++}
++
++void vhost_user_server_set_aio_context(VuServer *server, AioContext *ctx)
++{
++    VuFdWatch *vu_fd_watch, *next;
++    void *opaque = NULL;
++    IOHandler *io_read = NULL;
++    bool attach;
++
++    server->ctx = ctx ? ctx : qemu_get_aio_context();
++
++    if (!server->sioc) {
++        /* not yet serving any client*/
++        return;
++    }
++
++    if (ctx) {
++        qio_channel_attach_aio_context(server->ioc, ctx);
++        server->aio_context_changed = true;
++        io_read = kick_handler;
++        attach = true;
++    } else {
++        qio_channel_detach_aio_context(server->ioc);
++        /* server->ioc->ctx keeps the old AioConext */
++        ctx = server->ioc->ctx;
++        attach = false;
++    }
++
++    QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
++        if (vu_fd_watch->cb) {
++            opaque = attach ? vu_fd_watch : NULL;
++            aio_set_fd_handler(ctx, vu_fd_watch->fd, true,
++                               io_read, NULL, NULL,
++                               opaque);
++        }
++    }
++}
++
++
++bool vhost_user_server_start(VuServer *server,
++                             SocketAddress *socket_addr,
++                             AioContext *ctx,
++                             uint16_t max_queues,
++                             DevicePanicNotifierFn *device_panic_notifier,
++                             const VuDevIface *vu_iface,
++                             Error **errp)
++{
++    QIONetListener *listener = qio_net_listener_new();
++    if (qio_net_listener_open_sync(listener, socket_addr, 1,
++                                   errp) < 0) {
++        object_unref(OBJECT(listener));
++        return false;
++    }
++
++    /* zero out unspecified fileds */
++    *server = (VuServer) {
++        .listener              = listener,
++        .vu_iface              = vu_iface,
++        .max_queues            = max_queues,
++        .ctx                   = ctx,
++        .device_panic_notifier = device_panic_notifier,
++    };
++
++    qio_net_listener_set_name(server->listener, "vhost-user-backend-listener");
++
++    qio_net_listener_set_client_func(server->listener,
++                                     vu_accept,
++                                     server,
++                                     NULL);
++
++    QTAILQ_INIT(&server->vu_fd_watches);
++    return true;
++}
+diff --git a/util/meson.build b/util/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/util/meson.build
++++ b/util/meson.build
+@@ -XXX,XX +XXX,XX @@ if have_block
+   util_ss.add(files('main-loop.c'))
+   util_ss.add(files('nvdimm-utils.c'))
+   util_ss.add(files('qemu-coroutine.c', 'qemu-coroutine-lock.c', 'qemu-coroutine-io.c'))
++  util_ss.add(when: 'CONFIG_LINUX', if_true: files('vhost-user-server.c'))
+   util_ss.add(files('qemu-coroutine-sleep.c'))
+   util_ss.add(files('qemu-co-shared-resource.c'))
+   util_ss.add(files('thread-pool.c', 'qemu-timer.c'))
+--
+.26.2

-[Qemu-devel] [PULL 05/12] blockjob: separate monitor and blockjob APIs
+[PULL v2 05/28] block: move logical block size check function to a common utility function
-From: Paolo Bonzini <pbonzini@redhat.com>
+From: Coiby Xu <coiby.xu@gmail.com>
-We have two different headers for block job operations, blockjob.h
+Move the constants from hw/core/qdev-properties.c to
-and blockjob_int.h.  The former contains APIs called by the monitor,
+util/block-helpers.h so that knowledge of the min/max values is
 the latter contains APIs called by the block job drivers and the
 block layer itself.
-Keep the two APIs separate in the blockjob.c file too.  This will
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-be useful when transitioning away from the AioContext lock, because
+Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
-there will be locking policies for the two categories, too---the
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
-monitor will have to call new block_job_lock/unlock APIs, while blockjob
+Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
-APIs will take care of this for the users.
+Acked-by: Eduardo Habkost <ehabkost@redhat.com>
 Message-id: 20200918080912.321299-5-coiby.xu@gmail.com
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
  util/block-helpers.h             | 19 +++++++++++++
  hw/core/qdev-properties-system.c | 31 ++++-----------------
  util/block-helpers.c             | 46 ++++++++++++++++++++++++++++++++
  util/meson.build                 |  1 +
 files changed, 71 insertions(+), 26 deletions(-)
  create mode 100644 util/block-helpers.h
  create mode 100644 util/block-helpers.c
-Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+diff --git a/util/block-helpers.h b/util/block-helpers.h
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+new file mode 100644
-Message-id: 20170508141310.8674-6-pbonzini@redhat.com
+index XXXXXXX..XXXXXXX
-Signed-off-by: Jeff Cody <jcody@redhat.com>
+--- /dev/null
----
++++ b/util/block-helpers.h
- blockjob.c | 390 ++++++++++++++++++++++++++++++++-----------------------------
+@@ -XXX,XX +XXX,XX @@
-file changed, 205 insertions(+), 185 deletions(-)
++#ifndef BLOCK_HELPERS_H
++#define BLOCK_HELPERS_H
-diff --git a/blockjob.c b/blockjob.c
++
 +#include "qemu/units.h"
 +
 +/* lower limit is sector size */
 +#define MIN_BLOCK_SIZE          INT64_C(512)
 +#define MIN_BLOCK_SIZE_STR      "512 B"
 +/*
 + * upper limit is arbitrary, 2 MiB looks sufficient for all sensible uses, and
 + * matches qcow2 cluster size limit
 + */
 +#define MAX_BLOCK_SIZE          (2 * MiB)
 +#define MAX_BLOCK_SIZE_STR      "2 MiB"
 +
 +void check_block_size(const char *id, const char *name, int64_t value,
 +                      Error **errp);
 +
 +#endif /* BLOCK_HELPERS_H */
 diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
 index XXXXXXX..XXXXXXX 100644
---- a/blockjob.c
+--- a/hw/core/qdev-properties-system.c
-+++ b/blockjob.c
++++ b/hw/core/qdev-properties-system.c
-@@ -XXX,XX +XXX,XX @@ struct BlockJobTxn {
+@@ -XXX,XX +XXX,XX @@
+ #include "sysemu/blockdev.h"
- static QLIST_HEAD(, BlockJob) block_jobs = QLIST_HEAD_INITIALIZER(block_jobs);
+ #include "net/net.h"
+ #include "hw/pci/pci.h"
-+/*
++#include "util/block-helpers.h"
-+ * The block job API is composed of two categories of functions.
-+ *
+ static bool check_prop_still_unset(DeviceState *dev, const char *name,
-+ * The first includes functions used by the monitor.  The monitor is
+                                    const void *old_val, const char *new_val,
-+ * peculiar in that it accesses the block job list with block_job_get, and
+@@ -XXX,XX +XXX,XX @@ const PropertyInfo qdev_prop_losttickpolicy = {
-+ * therefore needs consistency across block_job_get and the actual operation
-+ * (e.g. block_job_set_speed).  The consistency is achieved with
+ /* --- blocksize --- */
-+ * aio_context_acquire/release.  These functions are declared in blockjob.h.
-+ *
+-/* lower limit is sector size */
-+ * The second includes functions used by the block job drivers and sometimes
+-#define MIN_BLOCK_SIZE          512
-+ * by the core block layer.  These do not care about locking, because the
+-#define MIN_BLOCK_SIZE_STR      "512 B"
-+ * whole coroutine runs under the AioContext lock, and are declared in
+-/*
-+ * blockjob_int.h.
+- * upper limit is arbitrary, 2 MiB looks sufficient for all sensible uses, and
-+ */
+- * matches qcow2 cluster size limit
-+
+- */
- BlockJob *block_job_next(BlockJob *job)
+-#define MAX_BLOCK_SIZE          (2 * MiB)
 -#define MAX_BLOCK_SIZE_STR      "2 MiB"
 -
  static void set_blocksize(Object *obj, Visitor *v, const char *name,
                            void *opaque, Error **errp)
  {
-     if (!job) {
+@@ -XXX,XX +XXX,XX @@ static void set_blocksize(Object *obj, Visitor *v, const char *name,
-@@ -XXX,XX +XXX,XX @@ int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
+     Property *prop = opaque;
-     return 0;
+     uint32_t *ptr = qdev_get_prop_ptr(dev, prop);
- }
+     uint64_t value;
++    Error *local_err = NULL;
--void *block_job_create(const char *job_id, const BlockJobDriver *driver,
--                       BlockDriverState *bs, uint64_t perm,
+     if (dev->realized) {
--                       uint64_t shared_perm, int64_t speed, int flags,
+         qdev_prop_set_after_realize(dev, name, errp);
--                       BlockCompletionFunc *cb, void *opaque, Error **errp)
+@@ -XXX,XX +XXX,XX @@ static void set_blocksize(Object *obj, Visitor *v, const char *name,
--{
+     if (!visit_type_size(v, name, &value, errp)) {
--    BlockBackend *blk;
+         return;
--    BlockJob *job;
+     }
--    int ret;
+-    /* value of 0 means "unset" */
 -    if (value && (value < MIN_BLOCK_SIZE || value > MAX_BLOCK_SIZE)) {
 -        error_setg(errp,
 -                   "Property %s.%s doesn't take value %" PRIu64
 -                   " (minimum: " MIN_BLOCK_SIZE_STR
 -                   ", maximum: " MAX_BLOCK_SIZE_STR ")",
 -                   dev->id ? : "", name, value);
 +    check_block_size(dev->id ? : "", name, value, &local_err);
 +    if (local_err) {
 +        error_propagate(errp, local_err);
          return;
      }
 -
--    if (bs->job) {
+-    /* We rely on power-of-2 blocksizes for bitmasks */
--        error_setg(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
+-    if ((value & (value - 1)) != 0) {
--        return NULL;
+-        error_setg(errp,
--    }
+-                  "Property %s.%s doesn't take value '%" PRId64 "', "
--
+-                  "it's not a power of 2", dev->id ?: "", name, (int64_t)value);
 -    if (job_id == NULL && !(flags & BLOCK_JOB_INTERNAL)) {
 -        job_id = bdrv_get_device_name(bs);
 -        if (!*job_id) {
 -            error_setg(errp, "An explicit job ID is required for this node");
 -            return NULL;
 -        }
 -    }
 -
 -    if (job_id) {
 -        if (flags & BLOCK_JOB_INTERNAL) {
 -            error_setg(errp, "Cannot specify job ID for internal block job");
 -            return NULL;
 -        }
 -
 -        if (!id_wellformed(job_id)) {
 -            error_setg(errp, "Invalid job ID '%s'", job_id);
 -            return NULL;
 -        }
 -
 -        if (block_job_get(job_id)) {
 -            error_setg(errp, "Job ID '%s' already in use", job_id);
 -            return NULL;
 -        }
 -    }
 -
 -    blk = blk_new(perm, shared_perm);
 -    ret = blk_insert_bs(blk, bs, errp);
 -    if (ret < 0) {
 -        blk_unref(blk);
 -        return NULL;
 -    }
 -
 -    job = g_malloc0(driver->instance_size);
 -    job->driver        = driver;
 -    job->id            = g_strdup(job_id);
 -    job->blk           = blk;
 -    job->cb            = cb;
 -    job->opaque        = opaque;
 -    job->busy          = false;
 -    job->paused        = true;
 -    job->pause_count   = 1;
 -    job->refcnt        = 1;
 -
 -    error_setg(&job->blocker, "block device is in use by block job: %s",
 -               BlockJobType_lookup[driver->job_type]);
 -    block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort);
 -    bs->job = job;
 -
 -    blk_set_dev_ops(blk, &block_job_dev_ops, job);
 -    bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
 -
 -    QLIST_INSERT_HEAD(&block_jobs, job, job_list);
 -
 -    blk_add_aio_context_notifier(blk, block_job_attached_aio_context,
 -                                 block_job_detach_aio_context, job);
 -
 -    /* Only set speed when necessary to avoid NotSupported error */
 -    if (speed != 0) {
 -        Error *local_err = NULL;
 -
 -        block_job_set_speed(job, speed, &local_err);
 -        if (local_err) {
 -            block_job_unref(job);
 -            error_propagate(errp, local_err);
 -            return NULL;
 -        }
 -    }
 -    return job;
 -}
 -
  bool block_job_is_internal(BlockJob *job)
  {
      return (job->id == NULL);
@@ -XXX,XX +XXX,XX @@ void block_job_start(BlockJob *job)
      bdrv_coroutine_enter(blk_bs(job->blk), job->co);
  }
 -void block_job_early_fail(BlockJob *job)
 -{
 -    block_job_unref(job);
 -}
 -
  static void block_job_completed_single(BlockJob *job)
  {
      if (!job->ret) {
@@ -XXX,XX +XXX,XX @@ static void block_job_completed_txn_success(BlockJob *job)
      }
  }
 -void block_job_completed(BlockJob *job, int ret)
 -{
 -    assert(blk_bs(job->blk)->job == job);
 -    assert(!job->completed);
 -    job->completed = true;
 -    job->ret = ret;
 -    if (!job->txn) {
 -        block_job_completed_single(job);
 -    } else if (ret < 0 || block_job_is_cancelled(job)) {
 -        block_job_completed_txn_abort(job);
 -    } else {
 -        block_job_completed_txn_success(job);
 -    }
 -}
 -
  void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
  {
      Error *local_err = NULL;
@@ -XXX,XX +XXX,XX @@ void block_job_user_pause(BlockJob *job)
      block_job_pause(job);
  }
 -static bool block_job_should_pause(BlockJob *job)
 -{
 -    return job->pause_count > 0;
 -}
 -
  bool block_job_user_paused(BlockJob *job)
  {
      return job->user_paused;
  }
 -void coroutine_fn block_job_pause_point(BlockJob *job)
 -{
 -    assert(job && block_job_started(job));
 -
 -    if (!block_job_should_pause(job)) {
 -        return;
 -    }
 -    if (block_job_is_cancelled(job)) {
 -        return;
 -    }
 -
--    if (job->driver->pause) {
+     *ptr = value;
 -        job->driver->pause(job);
 -    }
 -
 -    if (block_job_should_pause(job) && !block_job_is_cancelled(job)) {
 -        job->paused = true;
 -        job->busy = false;
 -        qemu_coroutine_yield(); /* wait for block_job_resume() */
 -        job->busy = true;
 -        job->paused = false;
 -    }
 -
 -    if (job->driver->resume) {
 -        job->driver->resume(job);
 -    }
 -}
 -
  void block_job_user_resume(BlockJob *job)
  {
      if (job && job->user_paused && job->pause_count > 0) {
@@ -XXX,XX +XXX,XX @@ void block_job_user_resume(BlockJob *job)
      }
  }
--void block_job_enter(BlockJob *job)
+diff --git a/util/block-helpers.c b/util/block-helpers.c
--{
+new file mode 100644
--    if (job->co && !job->busy) {
+index XXXXXXX..XXXXXXX
--        bdrv_coroutine_enter(blk_bs(job->blk), job->co);
+--- /dev/null
--    }
++++ b/util/block-helpers.c
--}
+@@ -XXX,XX +XXX,XX @@
 -
  void block_job_cancel(BlockJob *job)
  {
      if (block_job_started(job)) {
@@ -XXX,XX +XXX,XX @@ void block_job_cancel(BlockJob *job)
      }
  }
 -bool block_job_is_cancelled(BlockJob *job)
 -{
 -    return job->cancelled;
 -}
 -
  void block_job_iostatus_reset(BlockJob *job)
  {
      job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
@@ -XXX,XX +XXX,XX @@ int block_job_complete_sync(BlockJob *job, Error **errp)
      return block_job_finish_sync(job, &block_job_complete, errp);
  }
 -void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns)
 -{
 -    assert(job->busy);
 -
 -    /* Check cancellation *before* setting busy = false, too!  */
 -    if (block_job_is_cancelled(job)) {
 -        return;
 -    }
 -
 -    job->busy = false;
 -    if (!block_job_should_pause(job)) {
 -        co_aio_sleep_ns(blk_get_aio_context(job->blk), type, ns);
 -    }
 -    job->busy = true;
 -
 -    block_job_pause_point(job);
 -}
 -
 -void block_job_yield(BlockJob *job)
 -{
 -    assert(job->busy);
 -
 -    /* Check cancellation *before* setting busy = false, too!  */
 -    if (block_job_is_cancelled(job)) {
 -        return;
 -    }
 -
 -    job->busy = false;
 -    if (!block_job_should_pause(job)) {
 -        qemu_coroutine_yield();
 -    }
 -    job->busy = true;
 -
 -    block_job_pause_point(job);
 -}
 -
  BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
  {
      BlockJobInfo *info;
@@ -XXX,XX +XXX,XX @@ static void block_job_event_completed(BlockJob *job, const char *msg)
                                          &error_abort);
  }
 +/*
-+ * API for block job drivers and the block layer.  These functions are
++ * Block utility functions
-+ * declared in blockjob_int.h.
++ *
 + * Copyright IBM, Corp. 2011
 + * Copyright (c) 2020 Coiby Xu <coiby.xu@gmail.com>
 + *
 + * This work is licensed under the terms of the GNU GPL, version 2 or later.
 + * See the COPYING file in the top-level directory.
 + */
 +
-+void *block_job_create(const char *job_id, const BlockJobDriver *driver,
++#include "qemu/osdep.h"
-+                       BlockDriverState *bs, uint64_t perm,
++#include "qapi/error.h"
-+                       uint64_t shared_perm, int64_t speed, int flags,
++#include "qapi/qmp/qerror.h"
-+                       BlockCompletionFunc *cb, void *opaque, Error **errp)
++#include "block-helpers.h"
 +
 +/**
 + * check_block_size:
 + * @id: The unique ID of the object
 + * @name: The name of the property being validated
 + * @value: The block size in bytes
 + * @errp: A pointer to an area to store an error
 + *
 + * This function checks that the block size meets the following conditions:
 + * 1. At least MIN_BLOCK_SIZE
 + * 2. No larger than MAX_BLOCK_SIZE
 + * 3. A power of 2
 + */
 +void check_block_size(const char *id, const char *name, int64_t value,
 +                      Error **errp)
 +{
-+    BlockBackend *blk;
++    /* value of 0 means "unset" */
-+    BlockJob *job;
++    if (value && (value < MIN_BLOCK_SIZE || value > MAX_BLOCK_SIZE)) {
-+    int ret;
++        error_setg(errp, QERR_PROPERTY_VALUE_OUT_OF_RANGE,
-+
++                   id, name, value, MIN_BLOCK_SIZE, MAX_BLOCK_SIZE);
 +    if (bs->job) {
 +        error_setg(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
 +        return NULL;
 +    }
 +
 +    if (job_id == NULL && !(flags & BLOCK_JOB_INTERNAL)) {
 +        job_id = bdrv_get_device_name(bs);
 +        if (!*job_id) {
 +            error_setg(errp, "An explicit job ID is required for this node");
 +            return NULL;
 +        }
 +    }
 +
 +    if (job_id) {
 +        if (flags & BLOCK_JOB_INTERNAL) {
 +            error_setg(errp, "Cannot specify job ID for internal block job");
 +            return NULL;
 +        }
 +
 +        if (!id_wellformed(job_id)) {
 +            error_setg(errp, "Invalid job ID '%s'", job_id);
 +            return NULL;
 +        }
 +
 +        if (block_job_get(job_id)) {
 +            error_setg(errp, "Job ID '%s' already in use", job_id);
 +            return NULL;
 +        }
 +    }
 +
 +    blk = blk_new(perm, shared_perm);
 +    ret = blk_insert_bs(blk, bs, errp);
 +    if (ret < 0) {
 +        blk_unref(blk);
 +        return NULL;
 +    }
 +
 +    job = g_malloc0(driver->instance_size);
 +    job->driver        = driver;
 +    job->id            = g_strdup(job_id);
 +    job->blk           = blk;
 +    job->cb            = cb;
 +    job->opaque        = opaque;
 +    job->busy          = false;
 +    job->paused        = true;
 +    job->pause_count   = 1;
 +    job->refcnt        = 1;
 +
 +    error_setg(&job->blocker, "block device is in use by block job: %s",
 +               BlockJobType_lookup[driver->job_type]);
 +    block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort);
 +    bs->job = job;
 +
 +    blk_set_dev_ops(blk, &block_job_dev_ops, job);
 +    bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
 +
 +    QLIST_INSERT_HEAD(&block_jobs, job, job_list);
 +
 +    blk_add_aio_context_notifier(blk, block_job_attached_aio_context,
 +                                 block_job_detach_aio_context, job);
 +
 +    /* Only set speed when necessary to avoid NotSupported error */
 +    if (speed != 0) {
 +        Error *local_err = NULL;
 +
 +        block_job_set_speed(job, speed, &local_err);
 +        if (local_err) {
 +            block_job_unref(job);
 +            error_propagate(errp, local_err);
 +            return NULL;
 +        }
 +    }
 +    return job;
 +}
 +
  void block_job_pause_all(void)
  {
      BlockJob *job = NULL;
@@ -XXX,XX +XXX,XX @@ void block_job_pause_all(void)
      }
  }
 +void block_job_early_fail(BlockJob *job)
 +{
 +    block_job_unref(job);
 +}
 +
 +void block_job_completed(BlockJob *job, int ret)
 +{
 +    assert(blk_bs(job->blk)->job == job);
 +    assert(!job->completed);
 +    job->completed = true;
 +    job->ret = ret;
 +    if (!job->txn) {
 +        block_job_completed_single(job);
 +    } else if (ret < 0 || block_job_is_cancelled(job)) {
 +        block_job_completed_txn_abort(job);
 +    } else {
 +        block_job_completed_txn_success(job);
 +    }
 +}
 +
 +static bool block_job_should_pause(BlockJob *job)
 +{
 +    return job->pause_count > 0;
 +}
 +
 +void coroutine_fn block_job_pause_point(BlockJob *job)
 +{
 +    assert(job && block_job_started(job));
 +
 +    if (!block_job_should_pause(job)) {
 +        return;
 +    }
 +    if (block_job_is_cancelled(job)) {
 +        return;
 +    }
 +
-+    if (job->driver->pause) {
++    /* We rely on power-of-2 blocksizes for bitmasks */
-+        job->driver->pause(job);
++    if ((value & (value - 1)) != 0) {
-+    }
++        error_setg(errp,
-+
++                   "Property %s.%s doesn't take value '%" PRId64
-+    if (block_job_should_pause(job) && !block_job_is_cancelled(job)) {
++                   "', it's not a power of 2",
-+        job->paused = true;
++                   id, name, value);
-+        job->busy = false;
++        return;
 +        qemu_coroutine_yield(); /* wait for block_job_resume() */
 +        job->busy = true;
 +        job->paused = false;
 +    }
 +
 +    if (job->driver->resume) {
 +        job->driver->resume(job);
 +    }
 +}
-+
+diff --git a/util/meson.build b/util/meson.build
- void block_job_resume_all(void)
+index XXXXXXX..XXXXXXX 100644
- {
+--- a/util/meson.build
-     BlockJob *job = NULL;
++++ b/util/meson.build
-@@ -XXX,XX +XXX,XX @@ void block_job_resume_all(void)
+@@ -XXX,XX +XXX,XX @@ if have_block
-     }
+   util_ss.add(files('nvdimm-utils.c'))
- }
+   util_ss.add(files('qemu-coroutine.c', 'qemu-coroutine-lock.c', 'qemu-coroutine-io.c'))
+   util_ss.add(when: 'CONFIG_LINUX', if_true: files('vhost-user-server.c'))
-+void block_job_enter(BlockJob *job)
++  util_ss.add(files('block-helpers.c'))
-+{
+   util_ss.add(files('qemu-coroutine-sleep.c'))
-+    if (job->co && !job->busy) {
+   util_ss.add(files('qemu-co-shared-resource.c'))
-+        bdrv_coroutine_enter(blk_bs(job->blk), job->co);
+   util_ss.add(files('thread-pool.c', 'qemu-timer.c'))
 +    }
 +}
 +
 +bool block_job_is_cancelled(BlockJob *job)
 +{
 +    return job->cancelled;
 +}
 +
 +void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns)
 +{
 +    assert(job->busy);
 +
 +    /* Check cancellation *before* setting busy = false, too!  */
 +    if (block_job_is_cancelled(job)) {
 +        return;
 +    }
 +
 +    job->busy = false;
 +    if (!block_job_should_pause(job)) {
 +        co_aio_sleep_ns(blk_get_aio_context(job->blk), type, ns);
 +    }
 +    job->busy = true;
 +
 +    block_job_pause_point(job);
 +}
 +
 +void block_job_yield(BlockJob *job)
 +{
 +    assert(job->busy);
 +
 +    /* Check cancellation *before* setting busy = false, too!  */
 +    if (block_job_is_cancelled(job)) {
 +        return;
 +    }
 +
 +    job->busy = false;
 +    if (!block_job_should_pause(job)) {
 +        qemu_coroutine_yield();
 +    }
 +    job->busy = true;
 +
 +    block_job_pause_point(job);
 +}
 +
  void block_job_event_ready(BlockJob *job)
  {
      job->ready = true;
 --
-.9.3
+.26.2

-New patch
+[PULL v2 06/28] block/export: vhost-user block device backend server
+From: Coiby Xu <coiby.xu@gmail.com>
+By making use of libvhost-user, block device drive can be shared to
+the connected vhost-user client. Only one client can connect to the
+server one time.
+Since vhost-user-server needs a block drive to be created first, delay
+the creation of this object.
+Suggested-by: Kevin Wolf <kwolf@redhat.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
+Message-id: 20200918080912.321299-6-coiby.xu@gmail.com
+[Shorten "vhost_user_blk_server" string to "vhost_user_blk" to avoid the
+following compiler warning:
+../block/export/vhost-user-blk-server.c:178:50: error: ‘%s’ directive output truncated writing 21 bytes into a region of size 20 [-Werror=format-truncation=]
+and fix "Invalid size %ld ..." ssize_t format string arguments for
+-bit hosts.
+--Stefan]
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ block/export/vhost-user-blk-server.h |  36 ++
+ block/export/vhost-user-blk-server.c | 661 +++++++++++++++++++++++++++
+ softmmu/vl.c                         |   4 +
+ block/meson.build                    |   1 +
+files changed, 702 insertions(+)
+ create mode 100644 block/export/vhost-user-blk-server.h
+ create mode 100644 block/export/vhost-user-blk-server.c
+diff --git a/block/export/vhost-user-blk-server.h b/block/export/vhost-user-blk-server.h
+new file mode 100644
+index XXXXXXX..XXXXXXX
+--- /dev/null
++++ b/block/export/vhost-user-blk-server.h
+@@ -XXX,XX +XXX,XX @@
++/*
++ * Sharing QEMU block devices via vhost-user protocal
++ *
++ * Copyright (c) Coiby Xu <coiby.xu@gmail.com>.
++ * Copyright (c) 2020 Red Hat, Inc.
++ *
++ * This work is licensed under the terms of the GNU GPL, version 2 or
++ * later.  See the COPYING file in the top-level directory.
++ */
++
++#ifndef VHOST_USER_BLK_SERVER_H
++#define VHOST_USER_BLK_SERVER_H
++#include "util/vhost-user-server.h"
++
++typedef struct VuBlockDev VuBlockDev;
++#define TYPE_VHOST_USER_BLK_SERVER "vhost-user-blk-server"
++#define VHOST_USER_BLK_SERVER(obj) \
++   OBJECT_CHECK(VuBlockDev, obj, TYPE_VHOST_USER_BLK_SERVER)
++
++/* vhost user block device */
++struct VuBlockDev {
++    Object parent_obj;
++    char *node_name;
++    SocketAddress *addr;
++    AioContext *ctx;
++    VuServer vu_server;
++    bool running;
++    uint32_t blk_size;
++    BlockBackend *backend;
++    QIOChannelSocket *sioc;
++    QTAILQ_ENTRY(VuBlockDev) next;
++    struct virtio_blk_config blkcfg;
++    bool writable;
++};
++
++#endif /* VHOST_USER_BLK_SERVER_H */
+diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
+new file mode 100644
+index XXXXXXX..XXXXXXX
+--- /dev/null
++++ b/block/export/vhost-user-blk-server.c
+@@ -XXX,XX +XXX,XX @@
++/*
++ * Sharing QEMU block devices via vhost-user protocal
++ *
++ * Parts of the code based on nbd/server.c.
++ *
++ * Copyright (c) Coiby Xu <coiby.xu@gmail.com>.
++ * Copyright (c) 2020 Red Hat, Inc.
++ *
++ * This work is licensed under the terms of the GNU GPL, version 2 or
++ * later.  See the COPYING file in the top-level directory.
++ */
++#include "qemu/osdep.h"
++#include "block/block.h"
++#include "vhost-user-blk-server.h"
++#include "qapi/error.h"
++#include "qom/object_interfaces.h"
++#include "sysemu/block-backend.h"
++#include "util/block-helpers.h"
++
++enum {
++    VHOST_USER_BLK_MAX_QUEUES = 1,
++};
++struct virtio_blk_inhdr {
++    unsigned char status;
++};
++
++typedef struct VuBlockReq {
++    VuVirtqElement *elem;
++    int64_t sector_num;
++    size_t size;
++    struct virtio_blk_inhdr *in;
++    struct virtio_blk_outhdr out;
++    VuServer *server;
++    struct VuVirtq *vq;
++} VuBlockReq;
++
++static void vu_block_req_complete(VuBlockReq *req)
++{
++    VuDev *vu_dev = &req->server->vu_dev;
++
++    /* IO size with 1 extra status byte */
++    vu_queue_push(vu_dev, req->vq, req->elem, req->size + 1);
++    vu_queue_notify(vu_dev, req->vq);
++
++    if (req->elem) {
++        free(req->elem);
++    }
++
++    g_free(req);
++}
++
++static VuBlockDev *get_vu_block_device_by_server(VuServer *server)
++{
++    return container_of(server, VuBlockDev, vu_server);
++}
++
++static int coroutine_fn
++vu_block_discard_write_zeroes(VuBlockReq *req, struct iovec *iov,
++                              uint32_t iovcnt, uint32_t type)
++{
++    struct virtio_blk_discard_write_zeroes desc;
++    ssize_t size = iov_to_buf(iov, iovcnt, 0, &desc, sizeof(desc));
++    if (unlikely(size != sizeof(desc))) {
++        error_report("Invalid size %zd, expect %zu", size, sizeof(desc));
++        return -EINVAL;
++    }
++
++    VuBlockDev *vdev_blk = get_vu_block_device_by_server(req->server);
++    uint64_t range[2] = { le64_to_cpu(desc.sector) << 9,
++                          le32_to_cpu(desc.num_sectors) << 9 };
++    if (type == VIRTIO_BLK_T_DISCARD) {
++        if (blk_co_pdiscard(vdev_blk->backend, range[0], range[1]) == 0) {
++            return 0;
++        }
++    } else if (type == VIRTIO_BLK_T_WRITE_ZEROES) {
++        if (blk_co_pwrite_zeroes(vdev_blk->backend,
++                                 range[0], range[1], 0) == 0) {
++            return 0;
++        }
++    }
++
++    return -EINVAL;
++}
++
++static void coroutine_fn vu_block_flush(VuBlockReq *req)
++{
++    VuBlockDev *vdev_blk = get_vu_block_device_by_server(req->server);
++    BlockBackend *backend = vdev_blk->backend;
++    blk_co_flush(backend);
++}
++
++struct req_data {
++    VuServer *server;
++    VuVirtq *vq;
++    VuVirtqElement *elem;
++};
++
++static void coroutine_fn vu_block_virtio_process_req(void *opaque)
++{
++    struct req_data *data = opaque;
++    VuServer *server = data->server;
++    VuVirtq *vq = data->vq;
++    VuVirtqElement *elem = data->elem;
++    uint32_t type;
++    VuBlockReq *req;
++
++    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
++    BlockBackend *backend = vdev_blk->backend;
++
++    struct iovec *in_iov = elem->in_sg;
++    struct iovec *out_iov = elem->out_sg;
++    unsigned in_num = elem->in_num;
++    unsigned out_num = elem->out_num;
++    /* refer to hw/block/virtio_blk.c */
++    if (elem->out_num < 1 || elem->in_num < 1) {
++        error_report("virtio-blk request missing headers");
++        free(elem);
++        return;
++    }
++
++    req = g_new0(VuBlockReq, 1);
++    req->server = server;
++    req->vq = vq;
++    req->elem = elem;
++
++    if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
++                            sizeof(req->out)) != sizeof(req->out))) {
++        error_report("virtio-blk request outhdr too short");
++        goto err;
++    }
++
++    iov_discard_front(&out_iov, &out_num, sizeof(req->out));
++
++    if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
++        error_report("virtio-blk request inhdr too short");
++        goto err;
++    }
++
++    /* We always touch the last byte, so just see how big in_iov is.  */
++    req->in = (void *)in_iov[in_num - 1].iov_base
++              + in_iov[in_num - 1].iov_len
++              - sizeof(struct virtio_blk_inhdr);
++    iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr));
++
++    type = le32_to_cpu(req->out.type);
++    switch (type & ~VIRTIO_BLK_T_BARRIER) {
++    case VIRTIO_BLK_T_IN:
++    case VIRTIO_BLK_T_OUT: {
++        ssize_t ret = 0;
++        bool is_write = type & VIRTIO_BLK_T_OUT;
++        req->sector_num = le64_to_cpu(req->out.sector);
++
++        int64_t offset = req->sector_num * vdev_blk->blk_size;
++        QEMUIOVector qiov;
++        if (is_write) {
++            qemu_iovec_init_external(&qiov, out_iov, out_num);
++            ret = blk_co_pwritev(backend, offset, qiov.size,
++                                 &qiov, 0);
++        } else {
++            qemu_iovec_init_external(&qiov, in_iov, in_num);
++            ret = blk_co_preadv(backend, offset, qiov.size,
++                                &qiov, 0);
++        }
++        if (ret >= 0) {
++            req->in->status = VIRTIO_BLK_S_OK;
++        } else {
++            req->in->status = VIRTIO_BLK_S_IOERR;
++        }
++        break;
++    }
++    case VIRTIO_BLK_T_FLUSH:
++        vu_block_flush(req);
++        req->in->status = VIRTIO_BLK_S_OK;
++        break;
++    case VIRTIO_BLK_T_GET_ID: {
++        size_t size = MIN(iov_size(&elem->in_sg[0], in_num),
++                          VIRTIO_BLK_ID_BYTES);
++        snprintf(elem->in_sg[0].iov_base, size, "%s", "vhost_user_blk");
++        req->in->status = VIRTIO_BLK_S_OK;
++        req->size = elem->in_sg[0].iov_len;
++        break;
++    }
++    case VIRTIO_BLK_T_DISCARD:
++    case VIRTIO_BLK_T_WRITE_ZEROES: {
++        int rc;
++        rc = vu_block_discard_write_zeroes(req, &elem->out_sg[1],
++                                           out_num, type);
++        if (rc == 0) {
++            req->in->status = VIRTIO_BLK_S_OK;
++        } else {
++            req->in->status = VIRTIO_BLK_S_IOERR;
++        }
++        break;
++    }
++    default:
++        req->in->status = VIRTIO_BLK_S_UNSUPP;
++        break;
++    }
++
++    vu_block_req_complete(req);
++    return;
++
++err:
++    free(elem);
++    g_free(req);
++    return;
++}
++
++static void vu_block_process_vq(VuDev *vu_dev, int idx)
++{
++    VuServer *server;
++    VuVirtq *vq;
++    struct req_data *req_data;
++
++    server = container_of(vu_dev, VuServer, vu_dev);
++    assert(server);
++
++    vq = vu_get_queue(vu_dev, idx);
++    assert(vq);
++    VuVirtqElement *elem;
++    while (1) {
++        elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement) +
++                                    sizeof(VuBlockReq));
++        if (elem) {
++            req_data = g_new0(struct req_data, 1);
++            req_data->server = server;
++            req_data->vq = vq;
++            req_data->elem = elem;
++            Coroutine *co = qemu_coroutine_create(vu_block_virtio_process_req,
++                                                  req_data);
++            aio_co_enter(server->ioc->ctx, co);
++        } else {
++            break;
++        }
++    }
++}
++
++static void vu_block_queue_set_started(VuDev *vu_dev, int idx, bool started)
++{
++    VuVirtq *vq;
++
++    assert(vu_dev);
++
++    vq = vu_get_queue(vu_dev, idx);
++    vu_set_queue_handler(vu_dev, vq, started ? vu_block_process_vq : NULL);
++}
++
++static uint64_t vu_block_get_features(VuDev *dev)
++{
++    uint64_t features;
++    VuServer *server = container_of(dev, VuServer, vu_dev);
++    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
++    features = 1ull << VIRTIO_BLK_F_SIZE_MAX |
++               1ull << VIRTIO_BLK_F_SEG_MAX |
++               1ull << VIRTIO_BLK_F_TOPOLOGY |
++               1ull << VIRTIO_BLK_F_BLK_SIZE |
++               1ull << VIRTIO_BLK_F_FLUSH |
++               1ull << VIRTIO_BLK_F_DISCARD |
++               1ull << VIRTIO_BLK_F_WRITE_ZEROES |
++               1ull << VIRTIO_BLK_F_CONFIG_WCE |
++               1ull << VIRTIO_F_VERSION_1 |
++               1ull << VIRTIO_RING_F_INDIRECT_DESC |
++               1ull << VIRTIO_RING_F_EVENT_IDX |
++               1ull << VHOST_USER_F_PROTOCOL_FEATURES;
++
++    if (!vdev_blk->writable) {
++        features |= 1ull << VIRTIO_BLK_F_RO;
++    }
++
++    return features;
++}
++
++static uint64_t vu_block_get_protocol_features(VuDev *dev)
++{
++    return 1ull << VHOST_USER_PROTOCOL_F_CONFIG |
++           1ull << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD;
++}
++
++static int
++vu_block_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
++{
++    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
++    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
++    memcpy(config, &vdev_blk->blkcfg, len);
++
++    return 0;
++}
++
++static int
++vu_block_set_config(VuDev *vu_dev, const uint8_t *data,
++                    uint32_t offset, uint32_t size, uint32_t flags)
++{
++    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
++    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
++    uint8_t wce;
++
++    /* don't support live migration */
++    if (flags != VHOST_SET_CONFIG_TYPE_MASTER) {
++        return -EINVAL;
++    }
++
++    if (offset != offsetof(struct virtio_blk_config, wce) ||
++        size != 1) {
++        return -EINVAL;
++    }
++
++    wce = *data;
++    vdev_blk->blkcfg.wce = wce;
++    blk_set_enable_write_cache(vdev_blk->backend, wce);
++    return 0;
++}
++
++/*
++ * When the client disconnects, it sends a VHOST_USER_NONE request
++ * and vu_process_message will simple call exit which cause the VM
++ * to exit abruptly.
++ * To avoid this issue,  process VHOST_USER_NONE request ahead
++ * of vu_process_message.
++ *
++ */
++static int vu_block_process_msg(VuDev *dev, VhostUserMsg *vmsg, int *do_reply)
++{
++    if (vmsg->request == VHOST_USER_NONE) {
++        dev->panic(dev, "disconnect");
++        return true;
++    }
++    return false;
++}
++
++static const VuDevIface vu_block_iface = {
++    .get_features          = vu_block_get_features,
++    .queue_set_started     = vu_block_queue_set_started,
++    .get_protocol_features = vu_block_get_protocol_features,
++    .get_config            = vu_block_get_config,
++    .set_config            = vu_block_set_config,
++    .process_msg           = vu_block_process_msg,
++};
++
++static void blk_aio_attached(AioContext *ctx, void *opaque)
++{
++    VuBlockDev *vub_dev = opaque;
++    aio_context_acquire(ctx);
++    vhost_user_server_set_aio_context(&vub_dev->vu_server, ctx);
++    aio_context_release(ctx);
++}
++
++static void blk_aio_detach(void *opaque)
++{
++    VuBlockDev *vub_dev = opaque;
++    AioContext *ctx = vub_dev->vu_server.ctx;
++    aio_context_acquire(ctx);
++    vhost_user_server_set_aio_context(&vub_dev->vu_server, NULL);
++    aio_context_release(ctx);
++}
++
++static void
++vu_block_initialize_config(BlockDriverState *bs,
++                           struct virtio_blk_config *config, uint32_t blk_size)
++{
++    config->capacity = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
++    config->blk_size = blk_size;
++    config->size_max = 0;
++    config->seg_max = 128 - 2;
++    config->min_io_size = 1;
++    config->opt_io_size = 1;
++    config->num_queues = VHOST_USER_BLK_MAX_QUEUES;
++    config->max_discard_sectors = 32768;
++    config->max_discard_seg = 1;
++    config->discard_sector_alignment = config->blk_size >> 9;
++    config->max_write_zeroes_sectors = 32768;
++    config->max_write_zeroes_seg = 1;
++}
++
++static VuBlockDev *vu_block_init(VuBlockDev *vu_block_device, Error **errp)
++{
++
++    BlockBackend *blk;
++    Error *local_error = NULL;
++    const char *node_name = vu_block_device->node_name;
++    bool writable = vu_block_device->writable;
++    uint64_t perm = BLK_PERM_CONSISTENT_READ;
++    int ret;
++
++    AioContext *ctx;
++
++    BlockDriverState *bs = bdrv_lookup_bs(node_name, node_name, &local_error);
++
++    if (!bs) {
++        error_propagate(errp, local_error);
++        return NULL;
++    }
++
++    if (bdrv_is_read_only(bs)) {
++        writable = false;
++    }
++
++    if (writable) {
++        perm |= BLK_PERM_WRITE;
++    }
++
++    ctx = bdrv_get_aio_context(bs);
++    aio_context_acquire(ctx);
++    bdrv_invalidate_cache(bs, NULL);
++    aio_context_release(ctx);
++
++    /*
++     * Don't allow resize while the vhost user server is running,
++     * otherwise we don't care what happens with the node.
++     */
++    blk = blk_new(bdrv_get_aio_context(bs), perm,
++                  BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
++                  BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD);
++    ret = blk_insert_bs(blk, bs, errp);
++
++    if (ret < 0) {
++        goto fail;
++    }
++
++    blk_set_enable_write_cache(blk, false);
++
++    blk_set_allow_aio_context_change(blk, true);
++
++    vu_block_device->blkcfg.wce = 0;
++    vu_block_device->backend = blk;
++    if (!vu_block_device->blk_size) {
++        vu_block_device->blk_size = BDRV_SECTOR_SIZE;
++    }
++    vu_block_device->blkcfg.blk_size = vu_block_device->blk_size;
++    blk_set_guest_block_size(blk, vu_block_device->blk_size);
++    vu_block_initialize_config(bs, &vu_block_device->blkcfg,
++                                   vu_block_device->blk_size);
++    return vu_block_device;
++
++fail:
++    blk_unref(blk);
++    return NULL;
++}
++
++static void vu_block_deinit(VuBlockDev *vu_block_device)
++{
++    if (vu_block_device->backend) {
++        blk_remove_aio_context_notifier(vu_block_device->backend, blk_aio_attached,
++                                        blk_aio_detach, vu_block_device);
++    }
++
++    blk_unref(vu_block_device->backend);
++}
++
++static void vhost_user_blk_server_stop(VuBlockDev *vu_block_device)
++{
++    vhost_user_server_stop(&vu_block_device->vu_server);
++    vu_block_deinit(vu_block_device);
++}
++
++static void vhost_user_blk_server_start(VuBlockDev *vu_block_device,
++                                        Error **errp)
++{
++    AioContext *ctx;
++    SocketAddress *addr = vu_block_device->addr;
++
++    if (!vu_block_init(vu_block_device, errp)) {
++        return;
++    }
++
++    ctx = bdrv_get_aio_context(blk_bs(vu_block_device->backend));
++
++    if (!vhost_user_server_start(&vu_block_device->vu_server, addr, ctx,
++                                 VHOST_USER_BLK_MAX_QUEUES,
++                                 NULL, &vu_block_iface,
++                                 errp)) {
++        goto error;
++    }
++
++    blk_add_aio_context_notifier(vu_block_device->backend, blk_aio_attached,
++                                 blk_aio_detach, vu_block_device);
++    vu_block_device->running = true;
++    return;
++
++ error:
++    vu_block_deinit(vu_block_device);
++}
++
++static bool vu_prop_modifiable(VuBlockDev *vus, Error **errp)
++{
++    if (vus->running) {
++            error_setg(errp, "The property can't be modified "
++                       "while the server is running");
++            return false;
++    }
++    return true;
++}
++
++static void vu_set_node_name(Object *obj, const char *value, Error **errp)
++{
++    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
++
++    if (!vu_prop_modifiable(vus, errp)) {
++        return;
++    }
++
++    if (vus->node_name) {
++        g_free(vus->node_name);
++    }
++
++    vus->node_name = g_strdup(value);
++}
++
++static char *vu_get_node_name(Object *obj, Error **errp)
++{
++    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
++    return g_strdup(vus->node_name);
++}
++
++static void free_socket_addr(SocketAddress *addr)
++{
++        g_free(addr->u.q_unix.path);
++        g_free(addr);
++}
++
++static void vu_set_unix_socket(Object *obj, const char *value,
++                               Error **errp)
++{
++    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
++
++    if (!vu_prop_modifiable(vus, errp)) {
++        return;
++    }
++
++    if (vus->addr) {
++        free_socket_addr(vus->addr);
++    }
++
++    SocketAddress *addr = g_new0(SocketAddress, 1);
++    addr->type = SOCKET_ADDRESS_TYPE_UNIX;
++    addr->u.q_unix.path = g_strdup(value);
++    vus->addr = addr;
++}
++
++static char *vu_get_unix_socket(Object *obj, Error **errp)
++{
++    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
++    return g_strdup(vus->addr->u.q_unix.path);
++}
++
++static bool vu_get_block_writable(Object *obj, Error **errp)
++{
++    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
++    return vus->writable;
++}
++
++static void vu_set_block_writable(Object *obj, bool value, Error **errp)
++{
++    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
++
++    if (!vu_prop_modifiable(vus, errp)) {
++            return;
++    }
++
++    vus->writable = value;
++}
++
++static void vu_get_blk_size(Object *obj, Visitor *v, const char *name,
++                            void *opaque, Error **errp)
++{
++    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
++    uint32_t value = vus->blk_size;
++
++    visit_type_uint32(v, name, &value, errp);
++}
++
++static void vu_set_blk_size(Object *obj, Visitor *v, const char *name,
++                            void *opaque, Error **errp)
++{
++    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
++
++    Error *local_err = NULL;
++    uint32_t value;
++
++    if (!vu_prop_modifiable(vus, errp)) {
++            return;
++    }
++
++    visit_type_uint32(v, name, &value, &local_err);
++    if (local_err) {
++        goto out;
++    }
++
++    check_block_size(object_get_typename(obj), name, value, &local_err);
++    if (local_err) {
++        goto out;
++    }
++
++    vus->blk_size = value;
++
++out:
++    error_propagate(errp, local_err);
++}
++
++static void vhost_user_blk_server_instance_finalize(Object *obj)
++{
++    VuBlockDev *vub = VHOST_USER_BLK_SERVER(obj);
++
++    vhost_user_blk_server_stop(vub);
++
++    /*
++     * Unlike object_property_add_str, object_class_property_add_str
++     * doesn't have a release method. Thus manual memory freeing is
++     * needed.
++     */
++    free_socket_addr(vub->addr);
++    g_free(vub->node_name);
++}
++
++static void vhost_user_blk_server_complete(UserCreatable *obj, Error **errp)
++{
++    VuBlockDev *vub = VHOST_USER_BLK_SERVER(obj);
++
++    vhost_user_blk_server_start(vub, errp);
++}
++
++static void vhost_user_blk_server_class_init(ObjectClass *klass,
++                                             void *class_data)
++{
++    UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
++    ucc->complete = vhost_user_blk_server_complete;
++
++    object_class_property_add_bool(klass, "writable",
++                                   vu_get_block_writable,
++                                   vu_set_block_writable);
++
++    object_class_property_add_str(klass, "node-name",
++                                  vu_get_node_name,
++                                  vu_set_node_name);
++
++    object_class_property_add_str(klass, "unix-socket",
++                                  vu_get_unix_socket,
++                                  vu_set_unix_socket);
++
++    object_class_property_add(klass, "logical-block-size", "uint32",
++                              vu_get_blk_size, vu_set_blk_size,
++                              NULL, NULL);
++}
++
++static const TypeInfo vhost_user_blk_server_info = {
++    .name = TYPE_VHOST_USER_BLK_SERVER,
++    .parent = TYPE_OBJECT,
++    .instance_size = sizeof(VuBlockDev),
++    .instance_finalize = vhost_user_blk_server_instance_finalize,
++    .class_init = vhost_user_blk_server_class_init,
++    .interfaces = (InterfaceInfo[]) {
++        {TYPE_USER_CREATABLE},
++        {}
++    },
++};
++
++static void vhost_user_blk_server_register_types(void)
++{
++    type_register_static(&vhost_user_blk_server_info);
++}
++
++type_init(vhost_user_blk_server_register_types)
+diff --git a/softmmu/vl.c b/softmmu/vl.c
+index XXXXXXX..XXXXXXX 100644
+--- a/softmmu/vl.c
++++ b/softmmu/vl.c
+@@ -XXX,XX +XXX,XX @@ static bool object_create_initial(const char *type, QemuOpts *opts)
+     }
+ #endif
++    /* Reason: vhost-user-blk-server property "node-name" */
++    if (g_str_equal(type, "vhost-user-blk-server")) {
++        return false;
++    }
+     /*
+      * Reason: filter-* property "netdev" etc.
+      */
+diff --git a/block/meson.build b/block/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/block/meson.build
++++ b/block/meson.build
+@@ -XXX,XX +XXX,XX @@ block_ss.add(when: 'CONFIG_WIN32', if_true: files('file-win32.c', 'win32-aio.c')
+ block_ss.add(when: 'CONFIG_POSIX', if_true: [files('file-posix.c'), coref, iokit])
+ block_ss.add(when: 'CONFIG_LIBISCSI', if_true: files('iscsi-opts.c'))
+ block_ss.add(when: 'CONFIG_LINUX', if_true: files('nvme.c'))
++block_ss.add(when: 'CONFIG_LINUX', if_true: files('export/vhost-user-blk-server.c', '../contrib/libvhost-user/libvhost-user.c'))
+ block_ss.add(when: 'CONFIG_REPLICATION', if_true: files('replication.c'))
+ block_ss.add(when: 'CONFIG_SHEEPDOG', if_true: files('sheepdog.c'))
+ block_ss.add(when: ['CONFIG_LINUX_AIO', libaio], if_true: files('linux-aio.c'))
+--
+.26.2

-New patch
+[PULL v2 07/28] MAINTAINERS: Add vhost-user block device backend server maintainer
+From: Coiby Xu <coiby.xu@gmail.com>
+Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
+Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
+Message-id: 20200918080912.321299-8-coiby.xu@gmail.com
+[Removed reference to vhost-user-blk-test.c, it will be sent in a
+separate pull request.
+--Stefan]
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ MAINTAINERS | 7 +++++++
+file changed, 7 insertions(+)
+diff --git a/MAINTAINERS b/MAINTAINERS
+index XXXXXXX..XXXXXXX 100644
+--- a/MAINTAINERS
++++ b/MAINTAINERS
+@@ -XXX,XX +XXX,XX @@ L: qemu-block@nongnu.org
+ S: Supported
+ F: tests/image-fuzzer/
++Vhost-user block device backend server
++M: Coiby Xu <Coiby.Xu@gmail.com>
++S: Maintained
++F: block/export/vhost-user-blk-server.c
++F: util/vhost-user-server.c
++F: tests/qtest/libqos/vhost-user-blk.c
++
+ Replication
+ M: Wen Congyang <wencongyang2@huawei.com>
+ M: Xie Changlong <xiechanglong.d@gmail.com>
+--
+.26.2

-New patch
+[PULL v2 08/28] util/vhost-user-server: s/fileds/fields/ typo fix
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-id: 20200924151549.913737-3-stefanha@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ util/vhost-user-server.c | 2 +-
+file changed, 1 insertion(+), 1 deletion(-)
+diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/util/vhost-user-server.c
++++ b/util/vhost-user-server.c
+@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
+         return false;
+     }
+-    /* zero out unspecified fileds */
++    /* zero out unspecified fields */
+     *server = (VuServer) {
+         .listener              = listener,
+         .vu_iface              = vu_iface,
+--
+.26.2

-[Qemu-devel] [PULL 01/12] blockjob: remove unnecessary check
+[PULL v2 09/28] util/vhost-user-server: drop unnecessary QOM cast
-From: Paolo Bonzini <pbonzini@redhat.com>
+We already have access to the value with the correct type (ioc and sioc
 are the same QIOChannel).
-!job is always checked prior to the call, drop it from here.
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-id: 20200924151549.913737-4-stefanha@redhat.com
-Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
 Reviewed-by: Jeff Cody <jcody@redhat.com>
 Message-id: 20170508141310.8674-2-pbonzini@redhat.com
 Signed-off-by: Jeff Cody <jcody@redhat.com>
 ---
- blockjob.c | 2 +-
+ util/vhost-user-server.c | 2 +-
 file changed, 1 insertion(+), 1 deletion(-)
-diff --git a/blockjob.c b/blockjob.c
+diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
 index XXXXXXX..XXXXXXX 100644
---- a/blockjob.c
+--- a/util/vhost-user-server.c
-+++ b/blockjob.c
++++ b/util/vhost-user-server.c
-@@ -XXX,XX +XXX,XX @@ static bool block_job_should_pause(BlockJob *job)
+@@ -XXX,XX +XXX,XX @@ static void vu_accept(QIONetListener *listener, QIOChannelSocket *sioc,
+     server->ioc = QIO_CHANNEL(sioc);
- bool block_job_user_paused(BlockJob *job)
+     object_ref(OBJECT(server->ioc));
- {
+     qio_channel_attach_aio_context(server->ioc, server->ctx);
--    return job ? job->user_paused : 0;
+-    qio_channel_set_blocking(QIO_CHANNEL(server->sioc), false, NULL);
-+    return job->user_paused;
++    qio_channel_set_blocking(server->ioc, false, NULL);
      vu_client_start(server);
  }
- void coroutine_fn block_job_pause_point(BlockJob *job)
 --
-.9.3
+.26.2

-New patch
+[PULL v2 10/28] util/vhost-user-server: drop unnecessary watch deletion
+Explicitly deleting watches is not necessary since libvhost-user calls
+remove_watch() during vu_deinit(). Add an assertion to check this
+though.
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-id: 20200924151549.913737-5-stefanha@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ util/vhost-user-server.c | 19 ++++---------------
+file changed, 4 insertions(+), 15 deletions(-)
+diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/util/vhost-user-server.c
++++ b/util/vhost-user-server.c
+@@ -XXX,XX +XXX,XX @@ static void close_client(VuServer *server)
+     /* When this is set vu_client_trip will stop new processing vhost-user message */
+     server->sioc = NULL;
+-    VuFdWatch *vu_fd_watch, *next;
+-    QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
+-        aio_set_fd_handler(server->ioc->ctx, vu_fd_watch->fd, true, NULL,
+-                           NULL, NULL, NULL);
+-    }
+-
+-    while (!QTAILQ_EMPTY(&server->vu_fd_watches)) {
+-        QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
+-            if (!vu_fd_watch->processing) {
+-                QTAILQ_REMOVE(&server->vu_fd_watches, vu_fd_watch, next);
+-                g_free(vu_fd_watch);
+-            }
+-        }
+-    }
+-
+     while (server->processing_msg) {
+         if (server->ioc->read_coroutine) {
+             server->ioc->read_coroutine = NULL;
+@@ -XXX,XX +XXX,XX @@ static void close_client(VuServer *server)
+     }
+     vu_deinit(&server->vu_dev);
++
++    /* vu_deinit() should have called remove_watch() */
++    assert(QTAILQ_EMPTY(&server->vu_fd_watches));
++
+     object_unref(OBJECT(sioc));
+     object_unref(OBJECT(server->ioc));
+ }
+--
+.26.2

-[Qemu-devel] [PULL 07/12] blockjob: introduce block_job_cancel_async, check iostatus invariants
+[PULL v2 11/28] block/export: consolidate request structs into VuBlockReq
-From: Paolo Bonzini <pbonzini@redhat.com>
+Only one struct is needed per request. Drop req_data and the separate
 VuBlockReq instance. Instead let vu_queue_pop() allocate everything at
 once.
-The new functions helps respecting the invariant that the coroutine
+This fixes the req_data memory leak in vu_block_virtio_process_req().
 is entered with false user_resume, zero pause count and no error
 recorded in the iostatus.
-Resetting the iostatus is now common to all of block_job_cancel_async,
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-block_job_user_resume and block_job_iostatus_reset, albeit with slight
+Message-id: 20200924151549.913737-6-stefanha@redhat.com
-differences:
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
  block/export/vhost-user-blk-server.c | 68 +++++++++-------------------
 file changed, 21 insertions(+), 47 deletions(-)
-- block_job_cancel_async resets the iostatus, and resumes the job if
+diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
 there was an error, but the coroutine is not restarted immediately.
 For example the caller may continue with a call to block_job_finish_sync.
 - block_job_user_resume resets the iostatus.  It wants to resume the job
 unconditionally, even if there was no error.
 - block_job_iostatus_reset doesn't resume the job at all.  Maybe that's
 a bug but it should be fixed separately.
 block_job_iostatus_reset does the least common denominator, so add some
 checking but otherwise leave it as the entry point for resetting the
 iostatus.
 Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
 Message-id: 20170508141310.8674-8-pbonzini@redhat.com
 Signed-off-by: Jeff Cody <jcody@redhat.com>
 ---
  blockjob.c | 24 ++++++++++++++++++++----
 file changed, 20 insertions(+), 4 deletions(-)
 diff --git a/blockjob.c b/blockjob.c
 index XXXXXXX..XXXXXXX 100644
---- a/blockjob.c
+--- a/block/export/vhost-user-blk-server.c
-+++ b/blockjob.c
++++ b/block/export/vhost-user-blk-server.c
-@@ -XXX,XX +XXX,XX @@ static void block_job_completed_single(BlockJob *job)
+@@ -XXX,XX +XXX,XX @@ struct virtio_blk_inhdr {
-     block_job_unref(job);
+ };
  typedef struct VuBlockReq {
 -    VuVirtqElement *elem;
 +    VuVirtqElement elem;
      int64_t sector_num;
      size_t size;
      struct virtio_blk_inhdr *in;
@@ -XXX,XX +XXX,XX @@ static void vu_block_req_complete(VuBlockReq *req)
      VuDev *vu_dev = &req->server->vu_dev;
      /* IO size with 1 extra status byte */
 -    vu_queue_push(vu_dev, req->vq, req->elem, req->size + 1);
 +    vu_queue_push(vu_dev, req->vq, &req->elem, req->size + 1);
      vu_queue_notify(vu_dev, req->vq);
 -    if (req->elem) {
 -        free(req->elem);
 -    }
 -
 -    g_free(req);
 +    free(req);
  }
-+static void block_job_cancel_async(BlockJob *job)
+ static VuBlockDev *get_vu_block_device_by_server(VuServer *server)
-+{
+@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_flush(VuBlockReq *req)
-+    if (job->iostatus != BLOCK_DEVICE_IO_STATUS_OK) {
+     blk_co_flush(backend);
-+        block_job_iostatus_reset(job);
+ }
-+    }
-+    if (job->user_paused) {
+-struct req_data {
-+        /* Do not call block_job_enter here, the caller will handle it.  */
+-    VuServer *server;
-+        job->user_paused = false;
+-    VuVirtq *vq;
-+        job->pause_count--;
+-    VuVirtqElement *elem;
-+    }
+-};
-+    job->cancelled = true;
+-
-+}
+ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
  {
 -    struct req_data *data = opaque;
 -    VuServer *server = data->server;
 -    VuVirtq *vq = data->vq;
 -    VuVirtqElement *elem = data->elem;
 +    VuBlockReq *req = opaque;
 +    VuServer *server = req->server;
 +    VuVirtqElement *elem = &req->elem;
      uint32_t type;
 -    VuBlockReq *req;
      VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
      BlockBackend *backend = vdev_blk->backend;
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
      struct iovec *out_iov = elem->out_sg;
      unsigned in_num = elem->in_num;
      unsigned out_num = elem->out_num;
 +
- static void block_job_completed_txn_abort(BlockJob *job)
+     /* refer to hw/block/virtio_blk.c */
      if (elem->out_num < 1 || elem->in_num < 1) {
          error_report("virtio-blk request missing headers");
 -        free(elem);
 -        return;
 +        goto err;
      }
 -    req = g_new0(VuBlockReq, 1);
 -    req->server = server;
 -    req->vq = vq;
 -    req->elem = elem;
 -
      if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
                              sizeof(req->out)) != sizeof(req->out))) {
          error_report("virtio-blk request outhdr too short");
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
  err:
      free(elem);
 -    g_free(req);
 -    return;
  }
  static void vu_block_process_vq(VuDev *vu_dev, int idx)
  {
-     AioContext *ctx;
+-    VuServer *server;
-@@ -XXX,XX +XXX,XX @@ static void block_job_completed_txn_abort(BlockJob *job)
+-    VuVirtq *vq;
-              * them; this job, however, may or may not be cancelled, depending
+-    struct req_data *req_data;
-              * on the caller, so leave it. */
++    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
-             if (other_job != job) {
++    VuVirtq *vq = vu_get_queue(vu_dev, idx);
--                other_job->cancelled = true;
-+                block_job_cancel_async(other_job);
+-    server = container_of(vu_dev, VuServer, vu_dev);
-             }
+-    assert(server);
-             continue;
+-
 -    vq = vu_get_queue(vu_dev, idx);
 -    assert(vq);
 -    VuVirtqElement *elem;
      while (1) {
 -        elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement) +
 -                                    sizeof(VuBlockReq));
 -        if (elem) {
 -            req_data = g_new0(struct req_data, 1);
 -            req_data->server = server;
 -            req_data->vq = vq;
 -            req_data->elem = elem;
 -            Coroutine *co = qemu_coroutine_create(vu_block_virtio_process_req,
 -                                                  req_data);
 -            aio_co_enter(server->ioc->ctx, co);
 -        } else {
 +        VuBlockReq *req;
 +
 +        req = vu_queue_pop(vu_dev, vq, sizeof(VuBlockReq));
 +        if (!req) {
              break;
          }
-@@ -XXX,XX +XXX,XX @@ bool block_job_user_paused(BlockJob *job)
++
- void block_job_user_resume(BlockJob *job)
++        req->server = server;
- {
++        req->vq = vq;
-     if (job && job->user_paused && job->pause_count > 0) {
++
--        job->user_paused = false;
++        Coroutine *co =
-         block_job_iostatus_reset(job);
++            qemu_coroutine_create(vu_block_virtio_process_req, req);
-+        job->user_paused = false;
++        qemu_coroutine_enter(co);
          block_job_resume(job);
      }
  }
-@@ -XXX,XX +XXX,XX @@ void block_job_user_resume(BlockJob *job)
- void block_job_cancel(BlockJob *job)
- {
-     if (block_job_started(job)) {
--        job->cancelled = true;
--        block_job_iostatus_reset(job);
-+        block_job_cancel_async(job);
-         block_job_enter(job);
-     } else {
-         block_job_completed(job, -ECANCELED);
-@@ -XXX,XX +XXX,XX @@ void block_job_yield(BlockJob *job)
- void block_job_iostatus_reset(BlockJob *job)
- {
-+    if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
-+        return;
-+    }
-+    assert(job->user_paused && job->pause_count > 0);
-     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
- }
 --
-.9.3
+.26.2

-New patch
+[PULL v2 12/28] util/vhost-user-server: drop unused DevicePanicNotifier
+The device panic notifier callback is not used. Drop it.
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-id: 20200924151549.913737-7-stefanha@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ util/vhost-user-server.h             | 3 ---
+ block/export/vhost-user-blk-server.c | 3 +--
+ util/vhost-user-server.c             | 6 ------
+files changed, 1 insertion(+), 11 deletions(-)
+diff --git a/util/vhost-user-server.h b/util/vhost-user-server.h
+index XXXXXXX..XXXXXXX 100644
+--- a/util/vhost-user-server.h
++++ b/util/vhost-user-server.h
+@@ -XXX,XX +XXX,XX @@ typedef struct VuFdWatch {
+ } VuFdWatch;
+ typedef struct VuServer VuServer;
+-typedef void DevicePanicNotifierFn(VuServer *server);
+ struct VuServer {
+     QIONetListener *listener;
+     AioContext *ctx;
+-    DevicePanicNotifierFn *device_panic_notifier;
+     int max_queues;
+     const VuDevIface *vu_iface;
+     VuDev vu_dev;
+@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
+                              SocketAddress *unix_socket,
+                              AioContext *ctx,
+                              uint16_t max_queues,
+-                             DevicePanicNotifierFn *device_panic_notifier,
+                              const VuDevIface *vu_iface,
+                              Error **errp);
+diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/export/vhost-user-blk-server.c
++++ b/block/export/vhost-user-blk-server.c
+@@ -XXX,XX +XXX,XX @@ static void vhost_user_blk_server_start(VuBlockDev *vu_block_device,
+     ctx = bdrv_get_aio_context(blk_bs(vu_block_device->backend));
+     if (!vhost_user_server_start(&vu_block_device->vu_server, addr, ctx,
+-                                 VHOST_USER_BLK_MAX_QUEUES,
+-                                 NULL, &vu_block_iface,
++                                 VHOST_USER_BLK_MAX_QUEUES, &vu_block_iface,
+                                  errp)) {
+         goto error;
+     }
+diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/util/vhost-user-server.c
++++ b/util/vhost-user-server.c
+@@ -XXX,XX +XXX,XX @@ static void panic_cb(VuDev *vu_dev, const char *buf)
+         close_client(server);
+     }
+-    if (server->device_panic_notifier) {
+-        server->device_panic_notifier(server);
+-    }
+-
+     /*
+      * Set the callback function for network listener so another
+      * vhost-user client can connect to this server
+@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
+                              SocketAddress *socket_addr,
+                              AioContext *ctx,
+                              uint16_t max_queues,
+-                             DevicePanicNotifierFn *device_panic_notifier,
+                              const VuDevIface *vu_iface,
+                              Error **errp)
+ {
+@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
+         .vu_iface              = vu_iface,
+         .max_queues            = max_queues,
+         .ctx                   = ctx,
+-        .device_panic_notifier = device_panic_notifier,
+     };
+     qio_net_listener_set_name(server->listener, "vhost-user-backend-listener");
+--
+.26.2

-New patch
+[PULL v2 13/28] util/vhost-user-server: fix memory leak in vu_message_read()
+fds[] is leaked when qio_channel_readv_full() fails.
+Use vmsg->fds[] instead of keeping a local fds[] array. Then we can
+reuse goto fail to clean up fds. vmsg->fd_num must be zeroed before the
+loop to make this safe.
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-id: 20200924151549.913737-8-stefanha@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ util/vhost-user-server.c | 50 ++++++++++++++++++----------------------
+file changed, 23 insertions(+), 27 deletions(-)
+diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/util/vhost-user-server.c
++++ b/util/vhost-user-server.c
+@@ -XXX,XX +XXX,XX @@ vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg *vmsg)
+     };
+     int rc, read_bytes = 0;
+     Error *local_err = NULL;
+-    /*
+-     * Store fds/nfds returned from qio_channel_readv_full into
+-     * temporary variables.
+-     *
+-     * VhostUserMsg is a packed structure, gcc will complain about passing
+-     * pointer to a packed structure member if we pass &VhostUserMsg.fd_num
+-     * and &VhostUserMsg.fds directly when calling qio_channel_readv_full,
+-     * thus two temporary variables nfds and fds are used here.
+-     */
+-    size_t nfds = 0, nfds_t = 0;
+     const size_t max_fds = G_N_ELEMENTS(vmsg->fds);
+-    int *fds_t = NULL;
+     VuServer *server = container_of(vu_dev, VuServer, vu_dev);
+     QIOChannel *ioc = server->ioc;
++    vmsg->fd_num = 0;
+     if (!ioc) {
+         error_report_err(local_err);
+         goto fail;
+@@ -XXX,XX +XXX,XX @@ vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg *vmsg)
+     assert(qemu_in_coroutine());
+     do {
++        size_t nfds = 0;
++        int *fds = NULL;
++
+         /*
+          * qio_channel_readv_full may have short reads, keeping calling it
+          * until getting VHOST_USER_HDR_SIZE or 0 bytes in total
+          */
+-        rc = qio_channel_readv_full(ioc, &iov, 1, &fds_t, &nfds_t, &local_err);
++        rc = qio_channel_readv_full(ioc, &iov, 1, &fds, &nfds, &local_err);
+         if (rc < 0) {
+             if (rc == QIO_CHANNEL_ERR_BLOCK) {
++                assert(local_err == NULL);
+                 qio_channel_yield(ioc, G_IO_IN);
+                 continue;
+             } else {
+                 error_report_err(local_err);
+-                return false;
++                goto fail;
+             }
+         }
+-        read_bytes += rc;
+-        if (nfds_t > 0) {
+-            if (nfds + nfds_t > max_fds) {
++
++        if (nfds > 0) {
++            if (vmsg->fd_num + nfds > max_fds) {
+                 error_report("A maximum of %zu fds are allowed, "
+                              "however got %zu fds now",
+-                             max_fds, nfds + nfds_t);
++                             max_fds, vmsg->fd_num + nfds);
++                g_free(fds);
+                 goto fail;
+             }
+-            memcpy(vmsg->fds + nfds, fds_t,
+-                   nfds_t *sizeof(vmsg->fds[0]));
+-            nfds += nfds_t;
+-            g_free(fds_t);
++            memcpy(vmsg->fds + vmsg->fd_num, fds, nfds * sizeof(vmsg->fds[0]));
++            vmsg->fd_num += nfds;
++            g_free(fds);
+         }
+-        if (read_bytes == VHOST_USER_HDR_SIZE || rc == 0) {
+-            break;
++
++        if (rc == 0) { /* socket closed */
++            goto fail;
+         }
+-        iov.iov_base = (char *)vmsg + read_bytes;
+-        iov.iov_len = VHOST_USER_HDR_SIZE - read_bytes;
+-    } while (true);
+-    vmsg->fd_num = nfds;
++        iov.iov_base += rc;
++        iov.iov_len -= rc;
++        read_bytes += rc;
++    } while (read_bytes != VHOST_USER_HDR_SIZE);
++
+     /* qio_channel_readv_full will make socket fds blocking, unblock them */
+     vmsg_unblock_fds(vmsg);
+     if (vmsg->size > sizeof(vmsg->payload)) {
+--
+.26.2

-New patch
+[PULL v2 14/28] util/vhost-user-server: check EOF when reading payload
+Unexpected EOF is an error that must be reported.
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-id: 20200924151549.913737-9-stefanha@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ util/vhost-user-server.c | 6 ++++--
+file changed, 4 insertions(+), 2 deletions(-)
+diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/util/vhost-user-server.c
++++ b/util/vhost-user-server.c
+@@ -XXX,XX +XXX,XX @@ vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg *vmsg)
+     };
+     if (vmsg->size) {
+         rc = qio_channel_readv_all_eof(ioc, &iov_payload, 1, &local_err);
+-        if (rc == -1) {
+-            error_report_err(local_err);
++        if (rc != 1) {
++            if (local_err) {
++                error_report_err(local_err);
++            }
+             goto fail;
+         }
+     }
+--
+.26.2

-[Qemu-devel] [PULL 10/12] blockjob: reorganize block_job_completed_txn_abort
+[PULL v2 15/28] util/vhost-user-server: rework vu_client_trip() coroutine lifecycle
-From: Paolo Bonzini <pbonzini@redhat.com>
+The vu_client_trip() coroutine is leaked during AioContext switching. It
 is also unsafe to destroy the vu_dev in panic_cb() since its callers
 still access it in some cases.
-This splits the part that touches job states from the part that invokes
+Rework the lifecycle to solve these safety issues.
 callbacks.  It will make the code simpler to understand once job states will
 be protected by a different mutex than the AioContext lock.
-Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Message-id: 20200924151549.913737-10-stefanha@redhat.com
-Message-id: 20170508141310.8674-11-pbonzini@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 Signed-off-by: Jeff Cody <jcody@redhat.com>
 ---
- blockjob.c | 35 ++++++++++++++++++++++-------------
+ util/vhost-user-server.h             |  29 ++--
-file changed, 22 insertions(+), 13 deletions(-)
+ block/export/vhost-user-blk-server.c |   9 +-
  util/vhost-user-server.c             | 245 +++++++++++++++------------
 files changed, 155 insertions(+), 128 deletions(-)
-diff --git a/blockjob.c b/blockjob.c
+diff --git a/util/vhost-user-server.h b/util/vhost-user-server.h
 index XXXXXXX..XXXXXXX 100644
---- a/blockjob.c
+--- a/util/vhost-user-server.h
-+++ b/blockjob.c
++++ b/util/vhost-user-server.h
-@@ -XXX,XX +XXX,XX @@ void block_job_start(BlockJob *job)
+@@ -XXX,XX +XXX,XX @@
+ #include "qapi/error.h"
- static void block_job_completed_single(BlockJob *job)
+ #include "standard-headers/linux/virtio_blk.h"
- {
-+    assert(job->completed);
++/* A kick fd that we monitor on behalf of libvhost-user */
-+
+ typedef struct VuFdWatch {
-     if (!job->ret) {
+     VuDev *vu_dev;
-         if (job->driver->commit) {
+     int fd; /*kick fd*/
-             job->driver->commit(job);
+     void *pvt;
-@@ -XXX,XX +XXX,XX @@ static int block_job_finish_sync(BlockJob *job,
+     vu_watch_cb cb;
+-    bool processing;
-     block_job_ref(job);
+     QTAILQ_ENTRY(VuFdWatch) next;
+ } VuFdWatch;
--    finish(job, &local_err);
-+    if (finish) {
+-typedef struct VuServer VuServer;
-+        finish(job, &local_err);
+-
 -struct VuServer {
 +/**
 + * VuServer:
 + * A vhost-user server instance with user-defined VuDevIface callbacks.
 + * Vhost-user device backends can be implemented using VuServer. VuDevIface
 + * callbacks and virtqueue kicks run in the given AioContext.
 + */
 +typedef struct {
      QIONetListener *listener;
 +    QEMUBH *restart_listener_bh;
      AioContext *ctx;
      int max_queues;
      const VuDevIface *vu_iface;
 +
 +    /* Protected by ctx lock */
      VuDev vu_dev;
      QIOChannel *ioc; /* The I/O channel with the client */
      QIOChannelSocket *sioc; /* The underlying data channel with the client */
 -    /* IOChannel for fd provided via VHOST_USER_SET_SLAVE_REQ_FD */
 -    QIOChannel *ioc_slave;
 -    QIOChannelSocket *sioc_slave;
 -    Coroutine *co_trip; /* coroutine for processing VhostUserMsg */
      QTAILQ_HEAD(, VuFdWatch) vu_fd_watches;
 -    /* restart coroutine co_trip if AIOContext is changed */
 -    bool aio_context_changed;
 -    bool processing_msg;
 -};
 +
 +    Coroutine *co_trip; /* coroutine for processing VhostUserMsg */
 +} VuServer;
  bool vhost_user_server_start(VuServer *server,
                               SocketAddress *unix_socket,
@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
  void vhost_user_server_stop(VuServer *server);
 -void vhost_user_server_set_aio_context(VuServer *server, AioContext *ctx);
 +void vhost_user_server_attach_aio_context(VuServer *server, AioContext *ctx);
 +void vhost_user_server_detach_aio_context(VuServer *server);
  #endif /* VHOST_USER_SERVER_H */
 diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/export/vhost-user-blk-server.c
 +++ b/block/export/vhost-user-blk-server.c
@@ -XXX,XX +XXX,XX @@ static const VuDevIface vu_block_iface = {
  static void blk_aio_attached(AioContext *ctx, void *opaque)
  {
      VuBlockDev *vub_dev = opaque;
 -    aio_context_acquire(ctx);
 -    vhost_user_server_set_aio_context(&vub_dev->vu_server, ctx);
 -    aio_context_release(ctx);
 +    vhost_user_server_attach_aio_context(&vub_dev->vu_server, ctx);
  }
  static void blk_aio_detach(void *opaque)
  {
      VuBlockDev *vub_dev = opaque;
 -    AioContext *ctx = vub_dev->vu_server.ctx;
 -    aio_context_acquire(ctx);
 -    vhost_user_server_set_aio_context(&vub_dev->vu_server, NULL);
 -    aio_context_release(ctx);
 +    vhost_user_server_detach_aio_context(&vub_dev->vu_server);
  }
  static void
 diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
 index XXXXXXX..XXXXXXX 100644
 --- a/util/vhost-user-server.c
 +++ b/util/vhost-user-server.c
@@ -XXX,XX +XXX,XX @@
   */
  #include "qemu/osdep.h"
  #include "qemu/main-loop.h"
 +#include "block/aio-wait.h"
  #include "vhost-user-server.h"
 +/*
 + * Theory of operation:
 + *
 + * VuServer is started and stopped by vhost_user_server_start() and
 + * vhost_user_server_stop() from the main loop thread. Starting the server
 + * opens a vhost-user UNIX domain socket and listens for incoming connections.
 + * Only one connection is allowed at a time.
 + *
 + * The connection is handled by the vu_client_trip() coroutine in the
 + * VuServer->ctx AioContext. The coroutine consists of a vu_dispatch() loop
 + * where libvhost-user calls vu_message_read() to receive the next vhost-user
 + * protocol messages over the UNIX domain socket.
 + *
 + * When virtqueues are set up libvhost-user calls set_watch() to monitor kick
 + * fds. These fds are also handled in the VuServer->ctx AioContext.
 + *
 + * Both vu_client_trip() and kick fd monitoring can be stopped by shutting down
 + * the socket connection. Shutting down the socket connection causes
 + * vu_message_read() to fail since no more data can be received from the socket.
 + * After vu_dispatch() fails, vu_client_trip() calls vu_deinit() to stop
 + * libvhost-user before terminating the coroutine. vu_deinit() calls
 + * remove_watch() to stop monitoring kick fds and this stops virtqueue
 + * processing.
 + *
 + * When vu_client_trip() has finished cleaning up it schedules a BH in the main
 + * loop thread to accept the next client connection.
 + *
 + * When libvhost-user detects an error it calls panic_cb() and sets the
 + * dev->broken flag. Both vu_client_trip() and kick fd processing stop when
 + * the dev->broken flag is set.
 + *
 + * It is possible to switch AioContexts using
 + * vhost_user_server_detach_aio_context() and
 + * vhost_user_server_attach_aio_context(). They stop monitoring fds in the old
 + * AioContext and resume monitoring in the new AioContext. The vu_client_trip()
 + * coroutine remains in a yielded state during the switch. This is made
 + * possible by QIOChannel's support for spurious coroutine re-entry in
 + * qio_channel_yield(). The coroutine will restart I/O when re-entered from the
 + * new AioContext.
 + */
 +
  static void vmsg_close_fds(VhostUserMsg *vmsg)
  {
      int i;
@@ -XXX,XX +XXX,XX @@ static void vmsg_unblock_fds(VhostUserMsg *vmsg)
      }
  }
 -static void vu_accept(QIONetListener *listener, QIOChannelSocket *sioc,
 -                      gpointer opaque);
 -
 -static void close_client(VuServer *server)
 -{
 -    /*
 -     * Before closing the client
 -     *
 -     * 1. Let vu_client_trip stop processing new vhost-user msg
 -     *
 -     * 2. remove kick_handler
 -     *
 -     * 3. wait for the kick handler to be finished
 -     *
 -     * 4. wait for the current vhost-user msg to be finished processing
 -     */
 -
 -    QIOChannelSocket *sioc = server->sioc;
 -    /* When this is set vu_client_trip will stop new processing vhost-user message */
 -    server->sioc = NULL;
 -
 -    while (server->processing_msg) {
 -        if (server->ioc->read_coroutine) {
 -            server->ioc->read_coroutine = NULL;
 -            qio_channel_set_aio_fd_handler(server->ioc, server->ioc->ctx, NULL,
 -                                           NULL, server->ioc);
 -            server->processing_msg = false;
 -        }
 -    }
 -
 -    vu_deinit(&server->vu_dev);
 -
 -    /* vu_deinit() should have called remove_watch() */
 -    assert(QTAILQ_EMPTY(&server->vu_fd_watches));
 -
 -    object_unref(OBJECT(sioc));
 -    object_unref(OBJECT(server->ioc));
 -}
 -
  static void panic_cb(VuDev *vu_dev, const char *buf)
  {
 -    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
 -
 -    /* avoid while loop in close_client */
 -    server->processing_msg = false;
 -
 -    if (buf) {
 -        error_report("vu_panic: %s", buf);
 -    }
 -
 -    if (server->sioc) {
 -        close_client(server);
 -    }
 -
 -    /*
 -     * Set the callback function for network listener so another
 -     * vhost-user client can connect to this server
 -     */
 -    qio_net_listener_set_client_func(server->listener,
 -                                     vu_accept,
 -                                     server,
 -                                     NULL);
 +    error_report("vu_panic: %s", buf);
  }
  static bool coroutine_fn
@@ -XXX,XX +XXX,XX @@ fail:
      return false;
  }
 -
 -static void vu_client_start(VuServer *server);
  static coroutine_fn void vu_client_trip(void *opaque)
  {
      VuServer *server = opaque;
 +    VuDev *vu_dev = &server->vu_dev;
 -    while (!server->aio_context_changed && server->sioc) {
 -        server->processing_msg = true;
 -        vu_dispatch(&server->vu_dev);
 -        server->processing_msg = false;
 +    while (!vu_dev->broken && vu_dispatch(vu_dev)) {
 +        /* Keep running */
      }
 -    if (server->aio_context_changed && server->sioc) {
 -        server->aio_context_changed = false;
 -        vu_client_start(server);
 -    }
 -}
 +    vu_deinit(vu_dev);
 +
 +    /* vu_deinit() should have called remove_watch() */
 +    assert(QTAILQ_EMPTY(&server->vu_fd_watches));
 +
 +    object_unref(OBJECT(server->sioc));
 +    server->sioc = NULL;
 -static void vu_client_start(VuServer *server)
 -{
 -    server->co_trip = qemu_coroutine_create(vu_client_trip, server);
 -    aio_co_enter(server->ctx, server->co_trip);
 +    object_unref(OBJECT(server->ioc));
 +    server->ioc = NULL;
 +
 +    server->co_trip = NULL;
 +    if (server->restart_listener_bh) {
 +        qemu_bh_schedule(server->restart_listener_bh);
 +    }
-     if (local_err) {
++    aio_wait_kick();
-         error_propagate(errp, local_err);
+ }
-         block_job_unref(job);
-@@ -XXX,XX +XXX,XX @@ static void block_job_completed_txn_abort(BlockJob *job)
+ /*
- {
+@@ -XXX,XX +XXX,XX @@ static void vu_client_start(VuServer *server)
-     AioContext *ctx;
+ static void kick_handler(void *opaque)
-     BlockJobTxn *txn = job->txn;
+ {
--    BlockJob *other_job, *next;
+     VuFdWatch *vu_fd_watch = opaque;
-+    BlockJob *other_job;
+-    vu_fd_watch->processing = true;
+-    vu_fd_watch->cb(vu_fd_watch->vu_dev, 0, vu_fd_watch->pvt);
-     if (txn->aborting) {
+-    vu_fd_watch->processing = false;
-         /*
++    VuDev *vu_dev = vu_fd_watch->vu_dev;
-@@ -XXX,XX +XXX,XX @@ static void block_job_completed_txn_abort(BlockJob *job)
++
 +    vu_fd_watch->cb(vu_dev, 0, vu_fd_watch->pvt);
 +
 +    /* Stop vu_client_trip() if an error occurred in vu_fd_watch->cb() */
 +    if (vu_dev->broken) {
 +        VuServer *server = container_of(vu_dev, VuServer, vu_dev);
 +
 +        qio_channel_shutdown(server->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
 +    }
  }
 -
  static VuFdWatch *find_vu_fd_watch(VuServer *server, int fd)
  {
@@ -XXX,XX +XXX,XX @@ static void vu_accept(QIONetListener *listener, QIOChannelSocket *sioc,
      qio_channel_set_name(QIO_CHANNEL(sioc), "vhost-user client");
      server->ioc = QIO_CHANNEL(sioc);
      object_ref(OBJECT(server->ioc));
 -    qio_channel_attach_aio_context(server->ioc, server->ctx);
 +
 +    /* TODO vu_message_write() spins if non-blocking! */
      qio_channel_set_blocking(server->ioc, false, NULL);
 -    vu_client_start(server);
 +
 +    server->co_trip = qemu_coroutine_create(vu_client_trip, server);
 +
 +    aio_context_acquire(server->ctx);
 +    vhost_user_server_attach_aio_context(server, server->ctx);
 +    aio_context_release(server->ctx);
  }
 -
  void vhost_user_server_stop(VuServer *server)
  {
 +    aio_context_acquire(server->ctx);
 +
 +    qemu_bh_delete(server->restart_listener_bh);
 +    server->restart_listener_bh = NULL;
 +
      if (server->sioc) {
 -        close_client(server);
 +        VuFdWatch *vu_fd_watch;
 +
 +        QTAILQ_FOREACH(vu_fd_watch, &server->vu_fd_watches, next) {
 +            aio_set_fd_handler(server->ctx, vu_fd_watch->fd, true,
 +                               NULL, NULL, NULL, vu_fd_watch);
 +        }
 +
 +        qio_channel_shutdown(server->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
 +
 +        AIO_WAIT_WHILE(server->ctx, server->co_trip);
      }
 +    aio_context_release(server->ctx);
 +
      if (server->listener) {
          qio_net_listener_disconnect(server->listener);
          object_unref(OBJECT(server->listener));
      }
 +}
 +
 +/*
 + * Allow the next client to connect to the server. Called from a BH in the main
 + * loop.
 + */
 +static void restart_listener_bh(void *opaque)
 +{
 +    VuServer *server = opaque;
 +    qio_net_listener_set_client_func(server->listener, vu_accept, server,
 +                                     NULL);
  }
 -void vhost_user_server_set_aio_context(VuServer *server, AioContext *ctx)
 +/* Called with ctx acquired */
 +void vhost_user_server_attach_aio_context(VuServer *server, AioContext *ctx)
  {
 -    VuFdWatch *vu_fd_watch, *next;
 -    void *opaque = NULL;
 -    IOHandler *io_read = NULL;
 -    bool attach;
 +    VuFdWatch *vu_fd_watch;
 -    server->ctx = ctx ? ctx : qemu_get_aio_context();
 +    server->ctx = ctx;
      if (!server->sioc) {
 -        /* not yet serving any client*/
          return;
      }
-     txn->aborting = true;
-+    block_job_txn_ref(txn);
+-    if (ctx) {
-+
+-        qio_channel_attach_aio_context(server->ioc, ctx);
-     /* We are the first failed job. Cancel other jobs. */
+-        server->aio_context_changed = true;
-     QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
+-        io_read = kick_handler;
-         ctx = blk_get_aio_context(other_job->blk);
+-        attach = true;
-         aio_context_acquire(ctx);
+-    } else {
-     }
++    qio_channel_attach_aio_context(server->ioc, ctx);
 +
-+    /* Other jobs are effectively cancelled by us, set the status for
++    QTAILQ_FOREACH(vu_fd_watch, &server->vu_fd_watches, next) {
-+     * them; this job, however, may or may not be cancelled, depending
++        aio_set_fd_handler(ctx, vu_fd_watch->fd, true, kick_handler, NULL,
-+     * on the caller, so leave it. */
++                           NULL, vu_fd_watch);
-     QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
++    }
--        if (other_job == job || other_job->completed) {
++
--            /* Other jobs are "effectively" cancelled by us, set the status for
++    aio_co_schedule(ctx, server->co_trip);
--             * them; this job, however, may or may not be cancelled, depending
++}
--             * on the caller, so leave it. */
++
--            if (other_job != job) {
++/* Called with server->ctx acquired */
--                block_job_cancel_async(other_job);
++void vhost_user_server_detach_aio_context(VuServer *server)
--            }
++{
--            continue;
++    if (server->sioc) {
-+        if (other_job != job) {
++        VuFdWatch *vu_fd_watch;
-+            block_job_cancel_async(other_job);
++
-         }
++        QTAILQ_FOREACH(vu_fd_watch, &server->vu_fd_watches, next) {
--        block_job_cancel_sync(other_job);
++            aio_set_fd_handler(server->ctx, vu_fd_watch->fd, true,
--        assert(other_job->completed);
++                               NULL, NULL, NULL, vu_fd_watch);
      }
 -    QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) {
 +    while (!QLIST_EMPTY(&txn->jobs)) {
 +        other_job = QLIST_FIRST(&txn->jobs);
          ctx = blk_get_aio_context(other_job->blk);
 +        if (!other_job->completed) {
 +            assert(other_job->cancelled);
 +            block_job_finish_sync(other_job, NULL, NULL);
 +        }
-         block_job_completed_single(other_job);
++
-         aio_context_release(ctx);
+         qio_channel_detach_aio_context(server->ioc);
-     }
+-        /* server->ioc->ctx keeps the old AioConext */
-+
+-        ctx = server->ioc->ctx;
-+    block_job_txn_unref(txn);
+-        attach = false;
- }
+     }
- static void block_job_completed_txn_success(BlockJob *job)
+-    QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
 -        if (vu_fd_watch->cb) {
 -            opaque = attach ? vu_fd_watch : NULL;
 -            aio_set_fd_handler(ctx, vu_fd_watch->fd, true,
 -                               io_read, NULL, NULL,
 -                               opaque);
 -        }
 -    }
 +    server->ctx = NULL;
  }
 -
  bool vhost_user_server_start(VuServer *server,
                               SocketAddress *socket_addr,
                               AioContext *ctx,
@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
                               const VuDevIface *vu_iface,
                               Error **errp)
  {
 +    QEMUBH *bh;
      QIONetListener *listener = qio_net_listener_new();
      if (qio_net_listener_open_sync(listener, socket_addr, 1,
                                     errp) < 0) {
@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
          return false;
      }
 +    bh = qemu_bh_new(restart_listener_bh, server);
 +
      /* zero out unspecified fields */
      *server = (VuServer) {
          .listener              = listener,
 +        .restart_listener_bh   = bh,
          .vu_iface              = vu_iface,
          .max_queues            = max_queues,
          .ctx                   = ctx,
 --
-.9.3
+.26.2

-New patch
+[PULL v2 16/28] block/export: report flush errors
+Propagate the flush return value since errors are possible.
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-id: 20200924151549.913737-11-stefanha@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ block/export/vhost-user-blk-server.c | 11 +++++++----
+file changed, 7 insertions(+), 4 deletions(-)
+diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/export/vhost-user-blk-server.c
++++ b/block/export/vhost-user-blk-server.c
+@@ -XXX,XX +XXX,XX @@ vu_block_discard_write_zeroes(VuBlockReq *req, struct iovec *iov,
+     return -EINVAL;
+ }
+-static void coroutine_fn vu_block_flush(VuBlockReq *req)
++static int coroutine_fn vu_block_flush(VuBlockReq *req)
+ {
+     VuBlockDev *vdev_blk = get_vu_block_device_by_server(req->server);
+     BlockBackend *backend = vdev_blk->backend;
+-    blk_co_flush(backend);
++    return blk_co_flush(backend);
+ }
+ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
+@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
+         break;
+     }
+     case VIRTIO_BLK_T_FLUSH:
+-        vu_block_flush(req);
+-        req->in->status = VIRTIO_BLK_S_OK;
++        if (vu_block_flush(req) == 0) {
++            req->in->status = VIRTIO_BLK_S_OK;
++        } else {
++            req->in->status = VIRTIO_BLK_S_IOERR;
++        }
+         break;
+     case VIRTIO_BLK_T_GET_ID: {
+         size_t size = MIN(iov_size(&elem->in_sg[0], in_num),
+--
+.26.2

-[Qemu-devel] [PULL 06/12] blockjob: move iostatus reset inside block_job_user_resume
+[PULL v2 17/28] block/export: convert vhost-user-blk server to block export API
-From: Paolo Bonzini <pbonzini@redhat.com>
+Use the new QAPI block exports API instead of defining our own QOM
+objects.
-Outside blockjob.c, the block_job_iostatus_reset function is used once
-in the monitor and once in BlockBackend.  When we introduce the block
+This is a large change because the lifecycle of VuBlockDev needs to
-job mutex, block_job_iostatus_reset's client is going to be the block
+follow BlockExportDriver. QOM properties are replaced by QAPI options
-layer (for which blockjob.c will take the block job mutex) rather than
+objects.
-the monitor (which will take the block job mutex by itself).
+VuBlockDev is renamed VuBlkExport and contains a BlockExport field.
-The monitor's call to block_job_iostatus_reset from the monitor comes
+Several fields can be dropped since BlockExport already has equivalents.
-just before the sole call to block_job_user_resume, so reset the
-iostatus directly from block_job_iostatus_reset.  This will avoid
+The file names and meson build integration will be adjusted in a future
-the need to introduce separate block_job_iostatus_reset and
+patch. libvhost-user should probably be built as a static library that
-block_job_iostatus_reset_locked APIs.
+is linked into QEMU instead of as a .c file that results in duplicate
+compilation.
-After making this change, move the function together with the others
-that were moved in the previous patch.
+The new command-line syntax is:
-Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+  $ qemu-storage-daemon \
-Reviewed-by: John Snow <jsnow@redhat.com>
+      --blockdev file,node-name=drive0,filename=test.img \
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+      --export vhost-user-blk,node-name=drive0,id=export0,unix-socket=/tmp/vhost-user-blk.sock
-Reviewed-by: Jeff Cody <jcody@redhat.com>
-Message-id: 20170508141310.8674-7-pbonzini@redhat.com
+Note that unix-socket is optional because we may wish to accept chardevs
-Signed-off-by: Jeff Cody <jcody@redhat.com>
+too in the future.
 Markus noted that supported address families are not explicit in the
 QAPI schema. It is unlikely that support for more address families will
 be added since file descriptor passing is required and few address
 families support it. If a new address family needs to be added, then the
 QAPI 'features' syntax can be used to advertize them.
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 Acked-by: Markus Armbruster <armbru@redhat.com>
 Message-id: 20200924151549.913737-12-stefanha@redhat.com
 [Skip test on big-endian host architectures because this device doesn't
 support them yet (as already mentioned in a code comment).
 --Stefan]
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
- blockdev.c |  1 -
+ qapi/block-export.json               |  21 +-
- blockjob.c | 11 ++++++-----
+ block/export/vhost-user-blk-server.h |  23 +-
-files changed, 6 insertions(+), 6 deletions(-)
+ block/export/export.c                |   6 +
+ block/export/vhost-user-blk-server.c | 452 +++++++--------------------
-diff --git a/blockdev.c b/blockdev.c
+ util/vhost-user-server.c             |  10 +-
  block/export/meson.build             |   1 +
  block/meson.build                    |   1 -
 files changed, 156 insertions(+), 358 deletions(-)
 diff --git a/qapi/block-export.json b/qapi/block-export.json
 index XXXXXXX..XXXXXXX 100644
---- a/blockdev.c
+--- a/qapi/block-export.json
-+++ b/blockdev.c
++++ b/qapi/block-export.json
-@@ -XXX,XX +XXX,XX @@ void qmp_block_job_resume(const char *device, Error **errp)
+@@ -XXX,XX +XXX,XX @@
    'data': { '*name': 'str', '*description': 'str',
              '*bitmap': 'str' } }
 +##
 +# @BlockExportOptionsVhostUserBlk:
 +#
 +# A vhost-user-blk block export.
 +#
 +# @addr: The vhost-user socket on which to listen. Both 'unix' and 'fd'
 +#        SocketAddress types are supported. Passed fds must be UNIX domain
 +#        sockets.
 +# @logical-block-size: Logical block size in bytes. Defaults to 512 bytes.
 +#
 +# Since: 5.2
 +##
 +{ 'struct': 'BlockExportOptionsVhostUserBlk',
 +  'data': { 'addr': 'SocketAddress', '*logical-block-size': 'size' } }
 +
  ##
  # @NbdServerAddOptions:
  #
@@ -XXX,XX +XXX,XX @@
  # An enumeration of block export types
  #
  # @nbd: NBD export
 +# @vhost-user-blk: vhost-user-blk export (since 5.2)
  #
  # Since: 4.2
  ##
  { 'enum': 'BlockExportType',
 -  'data': [ 'nbd' ] }
 +  'data': [ 'nbd', 'vhost-user-blk' ] }
  ##
  # @BlockExportOptions:
@@ -XXX,XX +XXX,XX @@
              '*writethrough': 'bool' },
    'discriminator': 'type',
    'data': {
 -      'nbd': 'BlockExportOptionsNbd'
 +      'nbd': 'BlockExportOptionsNbd',
 +      'vhost-user-blk': 'BlockExportOptionsVhostUserBlk'
     } }
  ##
 diff --git a/block/export/vhost-user-blk-server.h b/block/export/vhost-user-blk-server.h
 index XXXXXXX..XXXXXXX 100644
 --- a/block/export/vhost-user-blk-server.h
 +++ b/block/export/vhost-user-blk-server.h
@@ -XXX,XX +XXX,XX @@
  #ifndef VHOST_USER_BLK_SERVER_H
  #define VHOST_USER_BLK_SERVER_H
 -#include "util/vhost-user-server.h"
 -typedef struct VuBlockDev VuBlockDev;
 -#define TYPE_VHOST_USER_BLK_SERVER "vhost-user-blk-server"
 -#define VHOST_USER_BLK_SERVER(obj) \
 -   OBJECT_CHECK(VuBlockDev, obj, TYPE_VHOST_USER_BLK_SERVER)
 +#include "block/export.h"
 -/* vhost user block device */
 -struct VuBlockDev {
 -    Object parent_obj;
 -    char *node_name;
 -    SocketAddress *addr;
 -    AioContext *ctx;
 -    VuServer vu_server;
 -    bool running;
 -    uint32_t blk_size;
 -    BlockBackend *backend;
 -    QIOChannelSocket *sioc;
 -    QTAILQ_ENTRY(VuBlockDev) next;
 -    struct virtio_blk_config blkcfg;
 -    bool writable;
 -};
 +/* For block/export/export.c */
 +extern const BlockExportDriver blk_exp_vhost_user_blk;
  #endif /* VHOST_USER_BLK_SERVER_H */
 diff --git a/block/export/export.c b/block/export/export.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/export/export.c
 +++ b/block/export/export.c
@@ -XXX,XX +XXX,XX @@
  #include "sysemu/block-backend.h"
  #include "block/export.h"
  #include "block/nbd.h"
 +#if CONFIG_LINUX
 +#include "block/export/vhost-user-blk-server.h"
 +#endif
  #include "qapi/error.h"
  #include "qapi/qapi-commands-block-export.h"
  #include "qapi/qapi-events-block-export.h"
@@ -XXX,XX +XXX,XX @@
  static const BlockExportDriver *blk_exp_drivers[] = {
      &blk_exp_nbd,
 +#if CONFIG_LINUX
 +    &blk_exp_vhost_user_blk,
 +#endif
  };
  /* Only accessed from the main thread */
 diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/export/vhost-user-blk-server.c
 +++ b/block/export/vhost-user-blk-server.c
@@ -XXX,XX +XXX,XX @@
   */
  #include "qemu/osdep.h"
  #include "block/block.h"
 +#include "contrib/libvhost-user/libvhost-user.h"
 +#include "standard-headers/linux/virtio_blk.h"
 +#include "util/vhost-user-server.h"
  #include "vhost-user-blk-server.h"
  #include "qapi/error.h"
  #include "qom/object_interfaces.h"
@@ -XXX,XX +XXX,XX @@ struct virtio_blk_inhdr {
      unsigned char status;
  };
 -typedef struct VuBlockReq {
 +typedef struct VuBlkReq {
      VuVirtqElement elem;
      int64_t sector_num;
      size_t size;
@@ -XXX,XX +XXX,XX @@ typedef struct VuBlockReq {
      struct virtio_blk_outhdr out;
      VuServer *server;
      struct VuVirtq *vq;
 -} VuBlockReq;
 +} VuBlkReq;
 -static void vu_block_req_complete(VuBlockReq *req)
 +/* vhost user block device */
 +typedef struct {
 +    BlockExport export;
 +    VuServer vu_server;
 +    uint32_t blk_size;
 +    QIOChannelSocket *sioc;
 +    struct virtio_blk_config blkcfg;
 +    bool writable;
 +} VuBlkExport;
 +
 +static void vu_blk_req_complete(VuBlkReq *req)
  {
      VuDev *vu_dev = &req->server->vu_dev;
@@ -XXX,XX +XXX,XX @@ static void vu_block_req_complete(VuBlockReq *req)
      free(req);
  }
 -static VuBlockDev *get_vu_block_device_by_server(VuServer *server)
 -{
 -    return container_of(server, VuBlockDev, vu_server);
 -}
 -
  static int coroutine_fn
 -vu_block_discard_write_zeroes(VuBlockReq *req, struct iovec *iov,
 -                              uint32_t iovcnt, uint32_t type)
 +vu_blk_discard_write_zeroes(BlockBackend *blk, struct iovec *iov,
 +                            uint32_t iovcnt, uint32_t type)
  {
      struct virtio_blk_discard_write_zeroes desc;
      ssize_t size = iov_to_buf(iov, iovcnt, 0, &desc, sizeof(desc));
@@ -XXX,XX +XXX,XX @@ vu_block_discard_write_zeroes(VuBlockReq *req, struct iovec *iov,
          return -EINVAL;
      }
-     trace_qmp_block_job_resume(job);
+-    VuBlockDev *vdev_blk = get_vu_block_device_by_server(req->server);
--    block_job_iostatus_reset(job);
+     uint64_t range[2] = { le64_to_cpu(desc.sector) << 9,
-     block_job_user_resume(job);
+                           le32_to_cpu(desc.num_sectors) << 9 };
-     aio_context_release(aio_context);
+     if (type == VIRTIO_BLK_T_DISCARD) {
- }
+-        if (blk_co_pdiscard(vdev_blk->backend, range[0], range[1]) == 0) {
-diff --git a/blockjob.c b/blockjob.c
++        if (blk_co_pdiscard(blk, range[0], range[1]) == 0) {
              return 0;
          }
      } else if (type == VIRTIO_BLK_T_WRITE_ZEROES) {
 -        if (blk_co_pwrite_zeroes(vdev_blk->backend,
 -                                 range[0], range[1], 0) == 0) {
 +        if (blk_co_pwrite_zeroes(blk, range[0], range[1], 0) == 0) {
              return 0;
          }
      }
@@ -XXX,XX +XXX,XX @@ vu_block_discard_write_zeroes(VuBlockReq *req, struct iovec *iov,
      return -EINVAL;
  }
 -static int coroutine_fn vu_block_flush(VuBlockReq *req)
 +static void coroutine_fn vu_blk_virtio_process_req(void *opaque)
  {
 -    VuBlockDev *vdev_blk = get_vu_block_device_by_server(req->server);
 -    BlockBackend *backend = vdev_blk->backend;
 -    return blk_co_flush(backend);
 -}
 -
 -static void coroutine_fn vu_block_virtio_process_req(void *opaque)
 -{
 -    VuBlockReq *req = opaque;
 +    VuBlkReq *req = opaque;
      VuServer *server = req->server;
      VuVirtqElement *elem = &req->elem;
      uint32_t type;
 -    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
 -    BlockBackend *backend = vdev_blk->backend;
 +    VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server);
 +    BlockBackend *blk = vexp->export.blk;
      struct iovec *in_iov = elem->in_sg;
      struct iovec *out_iov = elem->out_sg;
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
          bool is_write = type & VIRTIO_BLK_T_OUT;
          req->sector_num = le64_to_cpu(req->out.sector);
 -        int64_t offset = req->sector_num * vdev_blk->blk_size;
 +        if (is_write && !vexp->writable) {
 +            req->in->status = VIRTIO_BLK_S_IOERR;
 +            break;
 +        }
 +
 +        int64_t offset = req->sector_num * vexp->blk_size;
          QEMUIOVector qiov;
          if (is_write) {
              qemu_iovec_init_external(&qiov, out_iov, out_num);
 -            ret = blk_co_pwritev(backend, offset, qiov.size,
 -                                 &qiov, 0);
 +            ret = blk_co_pwritev(blk, offset, qiov.size, &qiov, 0);
          } else {
              qemu_iovec_init_external(&qiov, in_iov, in_num);
 -            ret = blk_co_preadv(backend, offset, qiov.size,
 -                                &qiov, 0);
 +            ret = blk_co_preadv(blk, offset, qiov.size, &qiov, 0);
          }
          if (ret >= 0) {
              req->in->status = VIRTIO_BLK_S_OK;
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
          break;
      }
      case VIRTIO_BLK_T_FLUSH:
 -        if (vu_block_flush(req) == 0) {
 +        if (blk_co_flush(blk) == 0) {
              req->in->status = VIRTIO_BLK_S_OK;
          } else {
              req->in->status = VIRTIO_BLK_S_IOERR;
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
      case VIRTIO_BLK_T_DISCARD:
      case VIRTIO_BLK_T_WRITE_ZEROES: {
          int rc;
 -        rc = vu_block_discard_write_zeroes(req, &elem->out_sg[1],
 -                                           out_num, type);
 +
 +        if (!vexp->writable) {
 +            req->in->status = VIRTIO_BLK_S_IOERR;
 +            break;
 +        }
 +
 +        rc = vu_blk_discard_write_zeroes(blk, &elem->out_sg[1], out_num, type);
          if (rc == 0) {
              req->in->status = VIRTIO_BLK_S_OK;
          } else {
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
          break;
      }
 -    vu_block_req_complete(req);
 +    vu_blk_req_complete(req);
      return;
  err:
 -    free(elem);
 +    free(req);
  }
 -static void vu_block_process_vq(VuDev *vu_dev, int idx)
 +static void vu_blk_process_vq(VuDev *vu_dev, int idx)
  {
      VuServer *server = container_of(vu_dev, VuServer, vu_dev);
      VuVirtq *vq = vu_get_queue(vu_dev, idx);
      while (1) {
 -        VuBlockReq *req;
 +        VuBlkReq *req;
 -        req = vu_queue_pop(vu_dev, vq, sizeof(VuBlockReq));
 +        req = vu_queue_pop(vu_dev, vq, sizeof(VuBlkReq));
          if (!req) {
              break;
          }
@@ -XXX,XX +XXX,XX @@ static void vu_block_process_vq(VuDev *vu_dev, int idx)
          req->vq = vq;
          Coroutine *co =
 -            qemu_coroutine_create(vu_block_virtio_process_req, req);
 +            qemu_coroutine_create(vu_blk_virtio_process_req, req);
          qemu_coroutine_enter(co);
      }
  }
 -static void vu_block_queue_set_started(VuDev *vu_dev, int idx, bool started)
 +static void vu_blk_queue_set_started(VuDev *vu_dev, int idx, bool started)
  {
      VuVirtq *vq;
      assert(vu_dev);
      vq = vu_get_queue(vu_dev, idx);
 -    vu_set_queue_handler(vu_dev, vq, started ? vu_block_process_vq : NULL);
 +    vu_set_queue_handler(vu_dev, vq, started ? vu_blk_process_vq : NULL);
  }
 -static uint64_t vu_block_get_features(VuDev *dev)
 +static uint64_t vu_blk_get_features(VuDev *dev)
  {
      uint64_t features;
      VuServer *server = container_of(dev, VuServer, vu_dev);
 -    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
 +    VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server);
      features = 1ull << VIRTIO_BLK_F_SIZE_MAX |
 ull << VIRTIO_BLK_F_SEG_MAX |
 ull << VIRTIO_BLK_F_TOPOLOGY |
@@ -XXX,XX +XXX,XX @@ static uint64_t vu_block_get_features(VuDev *dev)
 ull << VIRTIO_RING_F_EVENT_IDX |
 ull << VHOST_USER_F_PROTOCOL_FEATURES;
 -    if (!vdev_blk->writable) {
 +    if (!vexp->writable) {
          features |= 1ull << VIRTIO_BLK_F_RO;
      }
      return features;
  }
 -static uint64_t vu_block_get_protocol_features(VuDev *dev)
 +static uint64_t vu_blk_get_protocol_features(VuDev *dev)
  {
      return 1ull << VHOST_USER_PROTOCOL_F_CONFIG |
 ull << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD;
  }
  static int
 -vu_block_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
 +vu_blk_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
  {
 +    /* TODO blkcfg must be little-endian for VIRTIO 1.0 */
      VuServer *server = container_of(vu_dev, VuServer, vu_dev);
 -    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
 -    memcpy(config, &vdev_blk->blkcfg, len);
 -
 +    VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server);
 +    memcpy(config, &vexp->blkcfg, len);
      return 0;
  }
  static int
 -vu_block_set_config(VuDev *vu_dev, const uint8_t *data,
 +vu_blk_set_config(VuDev *vu_dev, const uint8_t *data,
                      uint32_t offset, uint32_t size, uint32_t flags)
  {
      VuServer *server = container_of(vu_dev, VuServer, vu_dev);
 -    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
 +    VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server);
      uint8_t wce;
      /* don't support live migration */
@@ -XXX,XX +XXX,XX @@ vu_block_set_config(VuDev *vu_dev, const uint8_t *data,
      }
      wce = *data;
 -    vdev_blk->blkcfg.wce = wce;
 -    blk_set_enable_write_cache(vdev_blk->backend, wce);
 +    vexp->blkcfg.wce = wce;
 +    blk_set_enable_write_cache(vexp->export.blk, wce);
      return 0;
  }
@@ -XXX,XX +XXX,XX @@ vu_block_set_config(VuDev *vu_dev, const uint8_t *data,
   * of vu_process_message.
   *
   */
 -static int vu_block_process_msg(VuDev *dev, VhostUserMsg *vmsg, int *do_reply)
 +static int vu_blk_process_msg(VuDev *dev, VhostUserMsg *vmsg, int *do_reply)
  {
      if (vmsg->request == VHOST_USER_NONE) {
          dev->panic(dev, "disconnect");
@@ -XXX,XX +XXX,XX @@ static int vu_block_process_msg(VuDev *dev, VhostUserMsg *vmsg, int *do_reply)
      return false;
  }
 -static const VuDevIface vu_block_iface = {
 -    .get_features          = vu_block_get_features,
 -    .queue_set_started     = vu_block_queue_set_started,
 -    .get_protocol_features = vu_block_get_protocol_features,
 -    .get_config            = vu_block_get_config,
 -    .set_config            = vu_block_set_config,
 -    .process_msg           = vu_block_process_msg,
 +static const VuDevIface vu_blk_iface = {
 +    .get_features          = vu_blk_get_features,
 +    .queue_set_started     = vu_blk_queue_set_started,
 +    .get_protocol_features = vu_blk_get_protocol_features,
 +    .get_config            = vu_blk_get_config,
 +    .set_config            = vu_blk_set_config,
 +    .process_msg           = vu_blk_process_msg,
  };
  static void blk_aio_attached(AioContext *ctx, void *opaque)
  {
 -    VuBlockDev *vub_dev = opaque;
 -    vhost_user_server_attach_aio_context(&vub_dev->vu_server, ctx);
 +    VuBlkExport *vexp = opaque;
 +    vhost_user_server_attach_aio_context(&vexp->vu_server, ctx);
  }
  static void blk_aio_detach(void *opaque)
  {
 -    VuBlockDev *vub_dev = opaque;
 -    vhost_user_server_detach_aio_context(&vub_dev->vu_server);
 +    VuBlkExport *vexp = opaque;
 +    vhost_user_server_detach_aio_context(&vexp->vu_server);
  }
  static void
 -vu_block_initialize_config(BlockDriverState *bs,
 +vu_blk_initialize_config(BlockDriverState *bs,
                             struct virtio_blk_config *config, uint32_t blk_size)
  {
      config->capacity = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
@@ -XXX,XX +XXX,XX @@ vu_block_initialize_config(BlockDriverState *bs,
      config->max_write_zeroes_seg = 1;
  }
 -static VuBlockDev *vu_block_init(VuBlockDev *vu_block_device, Error **errp)
 +static void vu_blk_exp_request_shutdown(BlockExport *exp)
  {
 +    VuBlkExport *vexp = container_of(exp, VuBlkExport, export);
 -    BlockBackend *blk;
 -    Error *local_error = NULL;
 -    const char *node_name = vu_block_device->node_name;
 -    bool writable = vu_block_device->writable;
 -    uint64_t perm = BLK_PERM_CONSISTENT_READ;
 -    int ret;
 -
 -    AioContext *ctx;
 -
 -    BlockDriverState *bs = bdrv_lookup_bs(node_name, node_name, &local_error);
 -
 -    if (!bs) {
 -        error_propagate(errp, local_error);
 -        return NULL;
 -    }
 -
 -    if (bdrv_is_read_only(bs)) {
 -        writable = false;
 -    }
 -
 -    if (writable) {
 -        perm |= BLK_PERM_WRITE;
 -    }
 -
 -    ctx = bdrv_get_aio_context(bs);
 -    aio_context_acquire(ctx);
 -    bdrv_invalidate_cache(bs, NULL);
 -    aio_context_release(ctx);
 -
 -    /*
 -     * Don't allow resize while the vhost user server is running,
 -     * otherwise we don't care what happens with the node.
 -     */
 -    blk = blk_new(bdrv_get_aio_context(bs), perm,
 -                  BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
 -                  BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD);
 -    ret = blk_insert_bs(blk, bs, errp);
 -
 -    if (ret < 0) {
 -        goto fail;
 -    }
 -
 -    blk_set_enable_write_cache(blk, false);
 -
 -    blk_set_allow_aio_context_change(blk, true);
 -
 -    vu_block_device->blkcfg.wce = 0;
 -    vu_block_device->backend = blk;
 -    if (!vu_block_device->blk_size) {
 -        vu_block_device->blk_size = BDRV_SECTOR_SIZE;
 -    }
 -    vu_block_device->blkcfg.blk_size = vu_block_device->blk_size;
 -    blk_set_guest_block_size(blk, vu_block_device->blk_size);
 -    vu_block_initialize_config(bs, &vu_block_device->blkcfg,
 -                                   vu_block_device->blk_size);
 -    return vu_block_device;
 -
 -fail:
 -    blk_unref(blk);
 -    return NULL;
 -}
 -
 -static void vu_block_deinit(VuBlockDev *vu_block_device)
 -{
 -    if (vu_block_device->backend) {
 -        blk_remove_aio_context_notifier(vu_block_device->backend, blk_aio_attached,
 -                                        blk_aio_detach, vu_block_device);
 -    }
 -
 -    blk_unref(vu_block_device->backend);
 -}
 -
 -static void vhost_user_blk_server_stop(VuBlockDev *vu_block_device)
 -{
 -    vhost_user_server_stop(&vu_block_device->vu_server);
 -    vu_block_deinit(vu_block_device);
 -}
 -
 -static void vhost_user_blk_server_start(VuBlockDev *vu_block_device,
 -                                        Error **errp)
 -{
 -    AioContext *ctx;
 -    SocketAddress *addr = vu_block_device->addr;
 -
 -    if (!vu_block_init(vu_block_device, errp)) {
 -        return;
 -    }
 -
 -    ctx = bdrv_get_aio_context(blk_bs(vu_block_device->backend));
 -
 -    if (!vhost_user_server_start(&vu_block_device->vu_server, addr, ctx,
 -                                 VHOST_USER_BLK_MAX_QUEUES, &vu_block_iface,
 -                                 errp)) {
 -        goto error;
 -    }
 -
 -    blk_add_aio_context_notifier(vu_block_device->backend, blk_aio_attached,
 -                                 blk_aio_detach, vu_block_device);
 -    vu_block_device->running = true;
 -    return;
 -
 - error:
 -    vu_block_deinit(vu_block_device);
 -}
 -
 -static bool vu_prop_modifiable(VuBlockDev *vus, Error **errp)
 -{
 -    if (vus->running) {
 -            error_setg(errp, "The property can't be modified "
 -                       "while the server is running");
 -            return false;
 -    }
 -    return true;
 -}
 -
 -static void vu_set_node_name(Object *obj, const char *value, Error **errp)
 -{
 -    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
 -
 -    if (!vu_prop_modifiable(vus, errp)) {
 -        return;
 -    }
 -
 -    if (vus->node_name) {
 -        g_free(vus->node_name);
 -    }
 -
 -    vus->node_name = g_strdup(value);
 -}
 -
 -static char *vu_get_node_name(Object *obj, Error **errp)
 -{
 -    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
 -    return g_strdup(vus->node_name);
 -}
 -
 -static void free_socket_addr(SocketAddress *addr)
 -{
 -        g_free(addr->u.q_unix.path);
 -        g_free(addr);
 -}
 -
 -static void vu_set_unix_socket(Object *obj, const char *value,
 -                               Error **errp)
 -{
 -    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
 -
 -    if (!vu_prop_modifiable(vus, errp)) {
 -        return;
 -    }
 -
 -    if (vus->addr) {
 -        free_socket_addr(vus->addr);
 -    }
 -
 -    SocketAddress *addr = g_new0(SocketAddress, 1);
 -    addr->type = SOCKET_ADDRESS_TYPE_UNIX;
 -    addr->u.q_unix.path = g_strdup(value);
 -    vus->addr = addr;
 +    vhost_user_server_stop(&vexp->vu_server);
  }
 -static char *vu_get_unix_socket(Object *obj, Error **errp)
 +static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
 +                             Error **errp)
  {
 -    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
 -    return g_strdup(vus->addr->u.q_unix.path);
 -}
 -
 -static bool vu_get_block_writable(Object *obj, Error **errp)
 -{
 -    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
 -    return vus->writable;
 -}
 -
 -static void vu_set_block_writable(Object *obj, bool value, Error **errp)
 -{
 -    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
 -
 -    if (!vu_prop_modifiable(vus, errp)) {
 -            return;
 -    }
 -
 -    vus->writable = value;
 -}
 -
 -static void vu_get_blk_size(Object *obj, Visitor *v, const char *name,
 -                            void *opaque, Error **errp)
 -{
 -    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
 -    uint32_t value = vus->blk_size;
 -
 -    visit_type_uint32(v, name, &value, errp);
 -}
 -
 -static void vu_set_blk_size(Object *obj, Visitor *v, const char *name,
 -                            void *opaque, Error **errp)
 -{
 -    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
 -
 +    VuBlkExport *vexp = container_of(exp, VuBlkExport, export);
 +    BlockExportOptionsVhostUserBlk *vu_opts = &opts->u.vhost_user_blk;
      Error *local_err = NULL;
 -    uint32_t value;
 +    uint64_t logical_block_size;
 -    if (!vu_prop_modifiable(vus, errp)) {
 -            return;
 -    }
 +    vexp->writable = opts->writable;
 +    vexp->blkcfg.wce = 0;
 -    visit_type_uint32(v, name, &value, &local_err);
 -    if (local_err) {
 -        goto out;
 +    if (vu_opts->has_logical_block_size) {
 +        logical_block_size = vu_opts->logical_block_size;
 +    } else {
 +        logical_block_size = BDRV_SECTOR_SIZE;
      }
 -
 -    check_block_size(object_get_typename(obj), name, value, &local_err);
 +    check_block_size(exp->id, "logical-block-size", logical_block_size,
 +                     &local_err);
      if (local_err) {
 -        goto out;
 +        error_propagate(errp, local_err);
 +        return -EINVAL;
 +    }
 +    vexp->blk_size = logical_block_size;
 +    blk_set_guest_block_size(exp->blk, logical_block_size);
 +    vu_blk_initialize_config(blk_bs(exp->blk), &vexp->blkcfg,
 +                               logical_block_size);
 +
 +    blk_set_allow_aio_context_change(exp->blk, true);
 +    blk_add_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
 +                                 vexp);
 +
 +    if (!vhost_user_server_start(&vexp->vu_server, vu_opts->addr, exp->ctx,
 +                                 VHOST_USER_BLK_MAX_QUEUES, &vu_blk_iface,
 +                                 errp)) {
 +        blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
 +                                        blk_aio_detach, vexp);
 +        return -EADDRNOTAVAIL;
      }
 -    vus->blk_size = value;
 -
 -out:
 -    error_propagate(errp, local_err);
 -}
 -
 -static void vhost_user_blk_server_instance_finalize(Object *obj)
 -{
 -    VuBlockDev *vub = VHOST_USER_BLK_SERVER(obj);
 -
 -    vhost_user_blk_server_stop(vub);
 -
 -    /*
 -     * Unlike object_property_add_str, object_class_property_add_str
 -     * doesn't have a release method. Thus manual memory freeing is
 -     * needed.
 -     */
 -    free_socket_addr(vub->addr);
 -    g_free(vub->node_name);
 -}
 -
 -static void vhost_user_blk_server_complete(UserCreatable *obj, Error **errp)
 -{
 -    VuBlockDev *vub = VHOST_USER_BLK_SERVER(obj);
 -
 -    vhost_user_blk_server_start(vub, errp);
 +    return 0;
  }
 -static void vhost_user_blk_server_class_init(ObjectClass *klass,
 -                                             void *class_data)
 +static void vu_blk_exp_delete(BlockExport *exp)
  {
 -    UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
 -    ucc->complete = vhost_user_blk_server_complete;
 -
 -    object_class_property_add_bool(klass, "writable",
 -                                   vu_get_block_writable,
 -                                   vu_set_block_writable);
 -
 -    object_class_property_add_str(klass, "node-name",
 -                                  vu_get_node_name,
 -                                  vu_set_node_name);
 -
 -    object_class_property_add_str(klass, "unix-socket",
 -                                  vu_get_unix_socket,
 -                                  vu_set_unix_socket);
 +    VuBlkExport *vexp = container_of(exp, VuBlkExport, export);
 -    object_class_property_add(klass, "logical-block-size", "uint32",
 -                              vu_get_blk_size, vu_set_blk_size,
 -                              NULL, NULL);
 +    blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
 +                                    vexp);
  }
 -static const TypeInfo vhost_user_blk_server_info = {
 -    .name = TYPE_VHOST_USER_BLK_SERVER,
 -    .parent = TYPE_OBJECT,
 -    .instance_size = sizeof(VuBlockDev),
 -    .instance_finalize = vhost_user_blk_server_instance_finalize,
 -    .class_init = vhost_user_blk_server_class_init,
 -    .interfaces = (InterfaceInfo[]) {
 -        {TYPE_USER_CREATABLE},
 -        {}
 -    },
 +const BlockExportDriver blk_exp_vhost_user_blk = {
 +    .type               = BLOCK_EXPORT_TYPE_VHOST_USER_BLK,
 +    .instance_size      = sizeof(VuBlkExport),
 +    .create             = vu_blk_exp_create,
 +    .delete             = vu_blk_exp_delete,
 +    .request_shutdown   = vu_blk_exp_request_shutdown,
  };
 -
 -static void vhost_user_blk_server_register_types(void)
 -{
 -    type_register_static(&vhost_user_blk_server_info);
 -}
 -
 -type_init(vhost_user_blk_server_register_types)
 diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
 index XXXXXXX..XXXXXXX 100644
---- a/blockjob.c
+--- a/util/vhost-user-server.c
-+++ b/blockjob.c
++++ b/util/vhost-user-server.c
-@@ -XXX,XX +XXX,XX @@ void block_job_user_resume(BlockJob *job)
+@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
- {
+                              Error **errp)
-     if (job && job->user_paused && job->pause_count > 0) {
+ {
-         job->user_paused = false;
+     QEMUBH *bh;
-+        block_job_iostatus_reset(job);
+-    QIONetListener *listener = qio_net_listener_new();
-         block_job_resume(job);
++    QIONetListener *listener;
      }
  }
@@ -XXX,XX +XXX,XX @@ void block_job_cancel(BlockJob *job)
      }
  }
 -void block_job_iostatus_reset(BlockJob *job)
 -{
 -    job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
 -}
 -
  static int block_job_finish_sync(BlockJob *job,
                                   void (*finish)(BlockJob *, Error **errp),
                                   Error **errp)
@@ -XXX,XX +XXX,XX @@ void block_job_yield(BlockJob *job)
      block_job_pause_point(job);
  }
 +void block_job_iostatus_reset(BlockJob *job)
 +{
 +    job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
 +}
 +
- void block_job_event_ready(BlockJob *job)
++    if (socket_addr->type != SOCKET_ADDRESS_TYPE_UNIX &&
- {
++        socket_addr->type != SOCKET_ADDRESS_TYPE_FD) {
-     job->ready = true;
++        error_setg(errp, "Only socket address types 'unix' and 'fd' are supported");
 +        return false;
 +    }
 +
 +    listener = qio_net_listener_new();
      if (qio_net_listener_open_sync(listener, socket_addr, 1,
                                     errp) < 0) {
          object_unref(OBJECT(listener));
 diff --git a/block/export/meson.build b/block/export/meson.build
 index XXXXXXX..XXXXXXX 100644
 --- a/block/export/meson.build
 +++ b/block/export/meson.build
@@ -1 +1,2 @@
  block_ss.add(files('export.c'))
 +block_ss.add(when: 'CONFIG_LINUX', if_true: files('vhost-user-blk-server.c', '../../contrib/libvhost-user/libvhost-user.c'))
 diff --git a/block/meson.build b/block/meson.build
 index XXXXXXX..XXXXXXX 100644
 --- a/block/meson.build
 +++ b/block/meson.build
@@ -XXX,XX +XXX,XX @@ block_ss.add(when: 'CONFIG_WIN32', if_true: files('file-win32.c', 'win32-aio.c')
  block_ss.add(when: 'CONFIG_POSIX', if_true: [files('file-posix.c'), coref, iokit])
  block_ss.add(when: 'CONFIG_LIBISCSI', if_true: files('iscsi-opts.c'))
  block_ss.add(when: 'CONFIG_LINUX', if_true: files('nvme.c'))
 -block_ss.add(when: 'CONFIG_LINUX', if_true: files('export/vhost-user-blk-server.c', '../contrib/libvhost-user/libvhost-user.c'))
  block_ss.add(when: 'CONFIG_REPLICATION', if_true: files('replication.c'))
  block_ss.add(when: 'CONFIG_SHEEPDOG', if_true: files('sheepdog.c'))
  block_ss.add(when: ['CONFIG_LINUX_AIO', libaio], if_true: files('linux-aio.c'))
 --
-.9.3
+.26.2

-New patch
+[PULL v2 18/28] util/vhost-user-server: move header to include/
+Headers used by other subsystems are located in include/. Also add the
+vhost-user-server and vhost-user-blk-server headers to MAINTAINERS.
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-id: 20200924151549.913737-13-stefanha@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ MAINTAINERS                                | 4 +++-
+ {util => include/qemu}/vhost-user-server.h | 0
+ block/export/vhost-user-blk-server.c       | 2 +-
+ util/vhost-user-server.c                   | 2 +-
+files changed, 5 insertions(+), 3 deletions(-)
+ rename {util => include/qemu}/vhost-user-server.h (100%)
+diff --git a/MAINTAINERS b/MAINTAINERS
+index XXXXXXX..XXXXXXX 100644
+--- a/MAINTAINERS
++++ b/MAINTAINERS
+@@ -XXX,XX +XXX,XX @@ Vhost-user block device backend server
+ M: Coiby Xu <Coiby.Xu@gmail.com>
+ S: Maintained
+ F: block/export/vhost-user-blk-server.c
+-F: util/vhost-user-server.c
++F: block/export/vhost-user-blk-server.h
++F: include/qemu/vhost-user-server.h
+ F: tests/qtest/libqos/vhost-user-blk.c
++F: util/vhost-user-server.c
+ Replication
+ M: Wen Congyang <wencongyang2@huawei.com>
+diff --git a/util/vhost-user-server.h b/include/qemu/vhost-user-server.h
+similarity index 100%
+rename from util/vhost-user-server.h
+rename to include/qemu/vhost-user-server.h
+diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/export/vhost-user-blk-server.c
++++ b/block/export/vhost-user-blk-server.c
+@@ -XXX,XX +XXX,XX @@
+ #include "block/block.h"
+ #include "contrib/libvhost-user/libvhost-user.h"
+ #include "standard-headers/linux/virtio_blk.h"
+-#include "util/vhost-user-server.h"
++#include "qemu/vhost-user-server.h"
+ #include "vhost-user-blk-server.h"
+ #include "qapi/error.h"
+ #include "qom/object_interfaces.h"
+diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/util/vhost-user-server.c
++++ b/util/vhost-user-server.c
+@@ -XXX,XX +XXX,XX @@
+  */
+ #include "qemu/osdep.h"
+ #include "qemu/main-loop.h"
++#include "qemu/vhost-user-server.h"
+ #include "block/aio-wait.h"
+-#include "vhost-user-server.h"
+ /*
+  * Theory of operation:
+--
+.26.2

-New patch
+[PULL v2 19/28] util/vhost-user-server: use static library in meson.build
+Don't compile contrib/libvhost-user/libvhost-user.c again. Instead build
+the static library once and then reuse it throughout QEMU.
+Also switch from CONFIG_LINUX to CONFIG_VHOST_USER, which is what the
+vhost-user tools (vhost-user-gpu, etc) do.
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-id: 20200924151549.913737-14-stefanha@redhat.com
+[Added CONFIG_LINUX again because libvhost-user doesn't build on macOS.
+--Stefan]
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ block/export/export.c             | 8 ++++----
+ block/export/meson.build          | 2 +-
+ contrib/libvhost-user/meson.build | 1 +
+ meson.build                       | 6 +++++-
+ util/meson.build                  | 4 +++-
+files changed, 14 insertions(+), 7 deletions(-)
+diff --git a/block/export/export.c b/block/export/export.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/export/export.c
++++ b/block/export/export.c
+@@ -XXX,XX +XXX,XX @@
+ #include "sysemu/block-backend.h"
+ #include "block/export.h"
+ #include "block/nbd.h"
+-#if CONFIG_LINUX
+-#include "block/export/vhost-user-blk-server.h"
+-#endif
+ #include "qapi/error.h"
+ #include "qapi/qapi-commands-block-export.h"
+ #include "qapi/qapi-events-block-export.h"
+ #include "qemu/id.h"
++#ifdef CONFIG_VHOST_USER
++#include "vhost-user-blk-server.h"
++#endif
+ static const BlockExportDriver *blk_exp_drivers[] = {
+     &blk_exp_nbd,
+-#if CONFIG_LINUX
++#ifdef CONFIG_VHOST_USER
+     &blk_exp_vhost_user_blk,
+ #endif
+ };
+diff --git a/block/export/meson.build b/block/export/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/block/export/meson.build
++++ b/block/export/meson.build
+@@ -XXX,XX +XXX,XX @@
+ block_ss.add(files('export.c'))
+-block_ss.add(when: 'CONFIG_LINUX', if_true: files('vhost-user-blk-server.c', '../../contrib/libvhost-user/libvhost-user.c'))
++block_ss.add(when: ['CONFIG_LINUX', 'CONFIG_VHOST_USER'], if_true: files('vhost-user-blk-server.c'))
+diff --git a/contrib/libvhost-user/meson.build b/contrib/libvhost-user/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/contrib/libvhost-user/meson.build
++++ b/contrib/libvhost-user/meson.build
+@@ -XXX,XX +XXX,XX @@
+ libvhost_user = static_library('vhost-user',
+                                files('libvhost-user.c', 'libvhost-user-glib.c'),
+                                build_by_default: false)
++vhost_user = declare_dependency(link_with: libvhost_user)
+diff --git a/meson.build b/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/meson.build
++++ b/meson.build
+@@ -XXX,XX +XXX,XX @@ trace_events_subdirs += [
+   'util',
+ ]
++vhost_user = not_found
++if 'CONFIG_VHOST_USER' in config_host
++  subdir('contrib/libvhost-user')
++endif
++
+ subdir('qapi')
+ subdir('qobject')
+ subdir('stubs')
+@@ -XXX,XX +XXX,XX @@ if have_tools
+              install: true)
+   if 'CONFIG_VHOST_USER' in config_host
+-    subdir('contrib/libvhost-user')
+     subdir('contrib/vhost-user-blk')
+     subdir('contrib/vhost-user-gpu')
+     subdir('contrib/vhost-user-input')
+diff --git a/util/meson.build b/util/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/util/meson.build
++++ b/util/meson.build
+@@ -XXX,XX +XXX,XX @@ if have_block
+   util_ss.add(files('main-loop.c'))
+   util_ss.add(files('nvdimm-utils.c'))
+   util_ss.add(files('qemu-coroutine.c', 'qemu-coroutine-lock.c', 'qemu-coroutine-io.c'))
+-  util_ss.add(when: 'CONFIG_LINUX', if_true: files('vhost-user-server.c'))
++  util_ss.add(when: ['CONFIG_LINUX', 'CONFIG_VHOST_USER'], if_true: [
++    files('vhost-user-server.c'), vhost_user
++  ])
+   util_ss.add(files('block-helpers.c'))
+   util_ss.add(files('qemu-coroutine-sleep.c'))
+   util_ss.add(files('qemu-co-shared-resource.c'))
+--
+.26.2

-New patch
+[PULL v2 20/28] qemu-storage-daemon: avoid compiling blockdev_ss twice
+Introduce libblkdev.fa to avoid recompiling blockdev_ss twice.
+Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
+Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-id: 20200929125516.186715-3-stefanha@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ meson.build                | 12 ++++++++++--
+ storage-daemon/meson.build |  3 +--
+files changed, 11 insertions(+), 4 deletions(-)
+diff --git a/meson.build b/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/meson.build
++++ b/meson.build
+@@ -XXX,XX +XXX,XX @@ blockdev_ss.add(files(
+ # os-win32.c does not
+ blockdev_ss.add(when: 'CONFIG_POSIX', if_true: files('os-posix.c'))
+ softmmu_ss.add(when: 'CONFIG_WIN32', if_true: [files('os-win32.c')])
+-softmmu_ss.add_all(blockdev_ss)
+ common_ss.add(files('cpus-common.c'))
+@@ -XXX,XX +XXX,XX @@ block = declare_dependency(link_whole: [libblock],
+                            link_args: '@block.syms',
+                            dependencies: [crypto, io])
++blockdev_ss = blockdev_ss.apply(config_host, strict: false)
++libblockdev = static_library('blockdev', blockdev_ss.sources() + genh,
++                             dependencies: blockdev_ss.dependencies(),
++                             name_suffix: 'fa',
++                             build_by_default: false)
++
++blockdev = declare_dependency(link_whole: [libblockdev],
++                              dependencies: [block])
++
+ qmp_ss = qmp_ss.apply(config_host, strict: false)
+ libqmp = static_library('qmp', qmp_ss.sources() + genh,
+                         dependencies: qmp_ss.dependencies(),
+@@ -XXX,XX +XXX,XX @@ foreach m : block_mods + softmmu_mods
+                 install_dir: config_host['qemu_moddir'])
+ endforeach
+-softmmu_ss.add(authz, block, chardev, crypto, io, qmp)
++softmmu_ss.add(authz, blockdev, chardev, crypto, io, qmp)
+ common_ss.add(qom, qemuutil)
+ common_ss.add_all(when: 'CONFIG_SOFTMMU', if_true: [softmmu_ss])
+diff --git a/storage-daemon/meson.build b/storage-daemon/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/storage-daemon/meson.build
++++ b/storage-daemon/meson.build
+@@ -XXX,XX +XXX,XX @@
+ qsd_ss = ss.source_set()
+ qsd_ss.add(files('qemu-storage-daemon.c'))
+-qsd_ss.add(block, chardev, qmp, qom, qemuutil)
+-qsd_ss.add_all(blockdev_ss)
++qsd_ss.add(blockdev, chardev, qmp, qom, qemuutil)
+ subdir('qapi')
+--
+.26.2

-New patch
+[PULL v2 21/28] block: move block exports to libblockdev
+Block exports are used by softmmu, qemu-storage-daemon, and qemu-nbd.
+They are not used by other programs and are not otherwise needed in
+libblock.
+Undo the recent move of blockdev-nbd.c from blockdev_ss into block_ss.
+Since bdrv_close_all() (libblock) calls blk_exp_close_all()
+(libblockdev) a stub function is required..
+Make qemu-nbd.c use signal handling utility functions instead of
+duplicating the code. This helps because os-posix.c is in libblockdev
+and it depends on a qemu_system_killed() symbol that qemu-nbd.c lacks.
+Once we use the signal handling utility functions we also end up
+providing the necessary symbol.
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
+Reviewed-by: Eric Blake <eblake@redhat.com>
+Message-id: 20200929125516.186715-4-stefanha@redhat.com
+[Fixed s/ndb/nbd/ typo in commit description as suggested by Eric Blake
+--Stefan]
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ qemu-nbd.c                | 21 ++++++++-------------
+ stubs/blk-exp-close-all.c |  7 +++++++
+ block/export/meson.build  |  4 ++--
+ meson.build               |  4 ++--
+ nbd/meson.build           |  2 ++
+ stubs/meson.build         |  1 +
+files changed, 22 insertions(+), 17 deletions(-)
+ create mode 100644 stubs/blk-exp-close-all.c
+diff --git a/qemu-nbd.c b/qemu-nbd.c
+index XXXXXXX..XXXXXXX 100644
+--- a/qemu-nbd.c
++++ b/qemu-nbd.c
+@@ -XXX,XX +XXX,XX @@
+ #include "qapi/error.h"
+ #include "qemu/cutils.h"
+ #include "sysemu/block-backend.h"
++#include "sysemu/runstate.h" /* for qemu_system_killed() prototype */
+ #include "block/block_int.h"
+ #include "block/nbd.h"
+ #include "qemu/main-loop.h"
+@@ -XXX,XX +XXX,XX @@ QEMU_COPYRIGHT "\n"
+ }
+ #ifdef CONFIG_POSIX
+-static void termsig_handler(int signum)
++/*
++ * The client thread uses SIGTERM to interrupt the server.  A signal
++ * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
++ */
++void qemu_system_killed(int signum, pid_t pid)
+ {
+     qatomic_cmpxchg(&state, RUNNING, TERMINATE);
+     qemu_notify_event();
+@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
+     BlockExportOptions *export_opts;
+ #ifdef CONFIG_POSIX
+-    /*
+-     * Exit gracefully on various signals, which includes SIGTERM used
+-     * by 'qemu-nbd -v -c'.
+-     */
+-    struct sigaction sa_sigterm;
+-    memset(&sa_sigterm, 0, sizeof(sa_sigterm));
+-    sa_sigterm.sa_handler = termsig_handler;
+-    sigaction(SIGTERM, &sa_sigterm, NULL);
+-    sigaction(SIGINT, &sa_sigterm, NULL);
+-    sigaction(SIGHUP, &sa_sigterm, NULL);
+-
+-    signal(SIGPIPE, SIG_IGN);
++    os_setup_early_signal_handling();
++    os_setup_signal_handling();
+ #endif
+     socket_init();
+diff --git a/stubs/blk-exp-close-all.c b/stubs/blk-exp-close-all.c
+new file mode 100644
+index XXXXXXX..XXXXXXX
+--- /dev/null
++++ b/stubs/blk-exp-close-all.c
+@@ -XXX,XX +XXX,XX @@
++#include "qemu/osdep.h"
++#include "block/export.h"
++
++/* Only used in programs that support block exports (libblockdev.fa) */
++void blk_exp_close_all(void)
++{
++}
+diff --git a/block/export/meson.build b/block/export/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/block/export/meson.build
++++ b/block/export/meson.build
+@@ -XXX,XX +XXX,XX @@
+-block_ss.add(files('export.c'))
+-block_ss.add(when: ['CONFIG_LINUX', 'CONFIG_VHOST_USER'], if_true: files('vhost-user-blk-server.c'))
++blockdev_ss.add(files('export.c'))
++blockdev_ss.add(when: ['CONFIG_LINUX', 'CONFIG_VHOST_USER'], if_true: files('vhost-user-blk-server.c'))
+diff --git a/meson.build b/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/meson.build
++++ b/meson.build
+@@ -XXX,XX +XXX,XX @@ subdir('dump')
+ block_ss.add(files(
+   'block.c',
+-  'blockdev-nbd.c',
+   'blockjob.c',
+   'job.c',
+   'qemu-io-cmds.c',
+@@ -XXX,XX +XXX,XX @@ subdir('block')
+ blockdev_ss.add(files(
+   'blockdev.c',
++  'blockdev-nbd.c',
+   'iothread.c',
+   'job-qmp.c',
+ ))
+@@ -XXX,XX +XXX,XX @@ if have_tools
+   qemu_io = executable('qemu-io', files('qemu-io.c'),
+              dependencies: [block, qemuutil], install: true)
+   qemu_nbd = executable('qemu-nbd', files('qemu-nbd.c'),
+-               dependencies: [block, qemuutil], install: true)
++               dependencies: [blockdev, qemuutil], install: true)
+   subdir('storage-daemon')
+   subdir('contrib/rdmacm-mux')
+diff --git a/nbd/meson.build b/nbd/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/nbd/meson.build
++++ b/nbd/meson.build
+@@ -XXX,XX +XXX,XX @@
+ block_ss.add(files(
+   'client.c',
+   'common.c',
++))
++blockdev_ss.add(files(
+   'server.c',
+ ))
+diff --git a/stubs/meson.build b/stubs/meson.build
+index XXXXXXX..XXXXXXX 100644
+--- a/stubs/meson.build
++++ b/stubs/meson.build
+@@ -XXX,XX +XXX,XX @@
+ stub_ss.add(files('arch_type.c'))
+ stub_ss.add(files('bdrv-next-monitor-owned.c'))
+ stub_ss.add(files('blk-commit-all.c'))
++stub_ss.add(files('blk-exp-close-all.c'))
+ stub_ss.add(files('blockdev-close-all-bdrv-states.c'))
+ stub_ss.add(files('change-state-handler.c'))
+ stub_ss.add(files('cmos.c'))
+--
+.26.2

-[Qemu-devel] [PULL 11/12] blockjob: use deferred_to_main_loop to indicate the coroutine has ended
+[PULL v2 22/28] block/export: add iothread and fixed-iothread options
-From: Paolo Bonzini <pbonzini@redhat.com>
+Make it possible to specify the iothread where the export will run. By
 default the block node can be moved to other AioContexts later and the
 export will follow. The fixed-iothread option forces strict behavior
 that prevents changing AioContext while the export is active. See the
 QAPI docs for details.
-All block jobs are using block_job_defer_to_main_loop as the final
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-step just before the coroutine terminates.  At this point,
+Message-id: 20200929125516.186715-5-stefanha@redhat.com
-block_job_enter should do nothing, but currently it restarts
+[Fix stray '#' character in block-export.json and add missing "(since:
-the freed coroutine.
+.2)" as suggested by Eric Blake.
 --Stefan]
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
  qapi/block-export.json               | 11 ++++++++++
  block/export/export.c                | 31 +++++++++++++++++++++++++++-
  block/export/vhost-user-blk-server.c |  5 ++++-
  nbd/server.c                         |  2 --
 files changed, 45 insertions(+), 4 deletions(-)
-Now, the job->co states should probably be changed to an enum
+diff --git a/qapi/block-export.json b/qapi/block-export.json
 (e.g. BEFORE_START, STARTED, YIELDED, COMPLETED) subsuming
 block_job_started, job->deferred_to_main_loop and job->busy.
 For now, this patch eliminates the problematic reenter by
 removing the reset of job->deferred_to_main_loop (which served
 no purpose, as far as I could see) and checking the flag in
 block_job_enter.
 Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
 Message-id: 20170508141310.8674-12-pbonzini@redhat.com
 Signed-off-by: Jeff Cody <jcody@redhat.com>
 ---
  blockjob.c                   | 10 ++++++++--
  include/block/blockjob_int.h |  3 ++-
 files changed, 10 insertions(+), 3 deletions(-)
 diff --git a/blockjob.c b/blockjob.c
 index XXXXXXX..XXXXXXX 100644
---- a/blockjob.c
+--- a/qapi/block-export.json
-+++ b/blockjob.c
++++ b/qapi/block-export.json
-@@ -XXX,XX +XXX,XX @@ void block_job_resume_all(void)
+@@ -XXX,XX +XXX,XX @@
+ #                export before completion is signalled. (since: 5.2;
- void block_job_enter(BlockJob *job)
+ #                default: false)
  #
 +# @iothread: The name of the iothread object where the export will run. The
 +#            default is to use the thread currently associated with the
 +#            block node. (since: 5.2)
 +#
 +# @fixed-iothread: True prevents the block node from being moved to another
 +#                  thread while the export is active. If true and @iothread is
 +#                  given, export creation fails if the block node cannot be
 +#                  moved to the iothread. The default is false. (since: 5.2)
 +#
  # Since: 4.2
  ##
  { 'union': 'BlockExportOptions',
    'base': { 'type': 'BlockExportType',
              'id': 'str',
 +        '*fixed-iothread': 'bool',
 +        '*iothread': 'str',
              'node-name': 'str',
              '*writable': 'bool',
              '*writethrough': 'bool' },
 diff --git a/block/export/export.c b/block/export/export.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/export/export.c
 +++ b/block/export/export.c
@@ -XXX,XX +XXX,XX @@
  #include "block/block.h"
  #include "sysemu/block-backend.h"
 +#include "sysemu/iothread.h"
  #include "block/export.h"
  #include "block/nbd.h"
  #include "qapi/error.h"
@@ -XXX,XX +XXX,XX @@ static const BlockExportDriver *blk_exp_find_driver(BlockExportType type)
  BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
  {
--    if (job->co && !job->busy) {
++    bool fixed_iothread = export->has_fixed_iothread && export->fixed_iothread;
-+    if (!block_job_started(job)) {
+     const BlockExportDriver *drv;
-+        return;
+     BlockExport *exp = NULL;
-+    }
+     BlockDriverState *bs;
-+    if (job->deferred_to_main_loop) {
+-    BlockBackend *blk;
-+        return;
++    BlockBackend *blk = NULL;
      AioContext *ctx;
      uint64_t perm;
      int ret;
@@ -XXX,XX +XXX,XX @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
      ctx = bdrv_get_aio_context(bs);
      aio_context_acquire(ctx);
 +    if (export->has_iothread) {
 +        IOThread *iothread;
 +        AioContext *new_ctx;
 +
 +        iothread = iothread_by_id(export->iothread);
 +        if (!iothread) {
 +            error_setg(errp, "iothread \"%s\" not found", export->iothread);
 +            goto fail;
 +        }
 +
 +        new_ctx = iothread_get_aio_context(iothread);
 +
 +        ret = bdrv_try_set_aio_context(bs, new_ctx, errp);
 +        if (ret == 0) {
 +            aio_context_release(ctx);
 +            aio_context_acquire(new_ctx);
 +            ctx = new_ctx;
 +        } else if (fixed_iothread) {
 +            goto fail;
 +        }
 +    }
 +
-+    if (!job->busy) {
+     /*
-         bdrv_coroutine_enter(blk_bs(job->blk), job->co);
+      * Block exports are used for non-shared storage migration. Make sure
       * that BDRV_O_INACTIVE is cleared and the image is ready for write
@@ -XXX,XX +XXX,XX @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
      }
+     blk = blk_new(ctx, perm, BLK_PERM_ALL);
++
++    if (!fixed_iothread) {
++        blk_set_allow_aio_context_change(blk, true);
++    }
++
+     ret = blk_insert_bs(blk, bs, errp);
+     if (ret < 0) {
+         goto fail;
+diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/export/vhost-user-blk-server.c
++++ b/block/export/vhost-user-blk-server.c
+@@ -XXX,XX +XXX,XX @@ static const VuDevIface vu_blk_iface = {
+ static void blk_aio_attached(AioContext *ctx, void *opaque)
+ {
+     VuBlkExport *vexp = opaque;
++
++    vexp->export.ctx = ctx;
+     vhost_user_server_attach_aio_context(&vexp->vu_server, ctx);
  }
-@@ -XXX,XX +XXX,XX @@ static void block_job_defer_to_main_loop_bh(void *opaque)
-         aio_context_acquire(aio_context);
+ static void blk_aio_detach(void *opaque)
  {
      VuBlkExport *vexp = opaque;
 +
      vhost_user_server_detach_aio_context(&vexp->vu_server);
 +    vexp->export.ctx = NULL;
  }
  static void
@@ -XXX,XX +XXX,XX @@ static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
      vu_blk_initialize_config(blk_bs(exp->blk), &vexp->blkcfg,
                                 logical_block_size);
 -    blk_set_allow_aio_context_change(exp->blk, true);
      blk_add_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
                                   vexp);
 diff --git a/nbd/server.c b/nbd/server.c
 index XXXXXXX..XXXXXXX 100644
 --- a/nbd/server.c
 +++ b/nbd/server.c
@@ -XXX,XX +XXX,XX @@ static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args,
          return ret;
      }
--    data->job->deferred_to_main_loop = false;
+-    blk_set_allow_aio_context_change(blk, true);
-     data->fn(data->job, data->opaque);
+-
+     QTAILQ_INIT(&exp->clients);
-     if (aio_context != data->aio_context) {
+     exp->name = g_strdup(arg->name);
-diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
+     exp->description = g_strdup(arg->description);
 index XXXXXXX..XXXXXXX 100644
 --- a/include/block/blockjob_int.h
 +++ b/include/block/blockjob_int.h
@@ -XXX,XX +XXX,XX @@ typedef void BlockJobDeferToMainLoopFn(BlockJob *job, void *opaque);
   * @fn: The function to run in the main loop
   * @opaque: The opaque value that is passed to @fn
   *
 - * Execute a given function in the main loop with the BlockDriverState
 + * This function must be called by the main job coroutine just before it
 + * returns.  @fn is executed in the main loop with the BlockDriverState
   * AioContext acquired.  Block jobs must call bdrv_unref(), bdrv_close(), and
   * anything that uses bdrv_drain_all() in the main loop.
   *
 --
-.9.3
+.26.2

-New patch
+[PULL v2 23/28] block/export: add vhost-user-blk multi-queue support
+Allow the number of queues to be configured using --export
+vhost-user-blk,num-queues=N. This setting should match the QEMU --device
+vhost-user-blk-pci,num-queues=N setting but QEMU vhost-user-blk.c lowers
+its own value if the vhost-user-blk backend offers fewer queues than
+QEMU.
+The vhost-user-blk-server.c code is already capable of multi-queue. All
+virtqueue processing runs in the same AioContext. No new locking is
+needed.
+Add the num-queues=N option and set the VIRTIO_BLK_F_MQ feature bit.
+Note that the feature bit only announces the presence of the num_queues
+configuration space field. It does not promise that there is more than 1
+virtqueue, so we can set it unconditionally.
+I tested multi-queue by running a random read fio test with numjobs=4 on
+an -smp 4 guest. After the benchmark finished the guest /proc/interrupts
+file showed activity on all 4 virtio-blk MSI-X. The /sys/block/vda/mq/
+directory shows that Linux blk-mq has 4 queues configured.
+An automated test is included in the next commit.
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Acked-by: Markus Armbruster <armbru@redhat.com>
+Message-id: 20201001144604.559733-2-stefanha@redhat.com
+[Fixed accidental tab characters as suggested by Markus Armbruster
+--Stefan]
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ qapi/block-export.json               | 10 +++++++---
+ block/export/vhost-user-blk-server.c | 24 ++++++++++++++++++------
+files changed, 25 insertions(+), 9 deletions(-)
+diff --git a/qapi/block-export.json b/qapi/block-export.json
+index XXXXXXX..XXXXXXX 100644
+--- a/qapi/block-export.json
++++ b/qapi/block-export.json
+@@ -XXX,XX +XXX,XX @@
+ #        SocketAddress types are supported. Passed fds must be UNIX domain
+ #        sockets.
+ # @logical-block-size: Logical block size in bytes. Defaults to 512 bytes.
++# @num-queues: Number of request virtqueues. Must be greater than 0. Defaults
++#              to 1.
+ #
+ # Since: 5.2
+ ##
+ { 'struct': 'BlockExportOptionsVhostUserBlk',
+-  'data': { 'addr': 'SocketAddress', '*logical-block-size': 'size' } }
++  'data': { 'addr': 'SocketAddress',
++        '*logical-block-size': 'size',
++            '*num-queues': 'uint16'} }
+ ##
+ # @NbdServerAddOptions:
+@@ -XXX,XX +XXX,XX @@
+ { 'union': 'BlockExportOptions',
+   'base': { 'type': 'BlockExportType',
+             'id': 'str',
+-        '*fixed-iothread': 'bool',
+-        '*iothread': 'str',
++            '*fixed-iothread': 'bool',
++            '*iothread': 'str',
+             'node-name': 'str',
+             '*writable': 'bool',
+             '*writethrough': 'bool' },
+diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/export/vhost-user-blk-server.c
++++ b/block/export/vhost-user-blk-server.c
+@@ -XXX,XX +XXX,XX @@
+ #include "util/block-helpers.h"
+ enum {
+-    VHOST_USER_BLK_MAX_QUEUES = 1,
++    VHOST_USER_BLK_NUM_QUEUES_DEFAULT = 1,
+ };
+ struct virtio_blk_inhdr {
+     unsigned char status;
+@@ -XXX,XX +XXX,XX @@ static uint64_t vu_blk_get_features(VuDev *dev)
+ull << VIRTIO_BLK_F_DISCARD |
+ull << VIRTIO_BLK_F_WRITE_ZEROES |
+ull << VIRTIO_BLK_F_CONFIG_WCE |
++               1ull << VIRTIO_BLK_F_MQ |
+ull << VIRTIO_F_VERSION_1 |
+ull << VIRTIO_RING_F_INDIRECT_DESC |
+ull << VIRTIO_RING_F_EVENT_IDX |
+@@ -XXX,XX +XXX,XX @@ static void blk_aio_detach(void *opaque)
+ static void
+ vu_blk_initialize_config(BlockDriverState *bs,
+-                           struct virtio_blk_config *config, uint32_t blk_size)
++                         struct virtio_blk_config *config,
++                         uint32_t blk_size,
++                         uint16_t num_queues)
+ {
+     config->capacity = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
+     config->blk_size = blk_size;
+@@ -XXX,XX +XXX,XX @@ vu_blk_initialize_config(BlockDriverState *bs,
+     config->seg_max = 128 - 2;
+     config->min_io_size = 1;
+     config->opt_io_size = 1;
+-    config->num_queues = VHOST_USER_BLK_MAX_QUEUES;
++    config->num_queues = num_queues;
+     config->max_discard_sectors = 32768;
+     config->max_discard_seg = 1;
+     config->discard_sector_alignment = config->blk_size >> 9;
+@@ -XXX,XX +XXX,XX @@ static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
+     BlockExportOptionsVhostUserBlk *vu_opts = &opts->u.vhost_user_blk;
+     Error *local_err = NULL;
+     uint64_t logical_block_size;
++    uint16_t num_queues = VHOST_USER_BLK_NUM_QUEUES_DEFAULT;
+     vexp->writable = opts->writable;
+     vexp->blkcfg.wce = 0;
+@@ -XXX,XX +XXX,XX @@ static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
+     }
+     vexp->blk_size = logical_block_size;
+     blk_set_guest_block_size(exp->blk, logical_block_size);
++
++    if (vu_opts->has_num_queues) {
++        num_queues = vu_opts->num_queues;
++    }
++    if (num_queues == 0) {
++        error_setg(errp, "num-queues must be greater than 0");
++        return -EINVAL;
++    }
++
+     vu_blk_initialize_config(blk_bs(exp->blk), &vexp->blkcfg,
+-                               logical_block_size);
++                             logical_block_size, num_queues);
+     blk_add_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
+                                  vexp);
+     if (!vhost_user_server_start(&vexp->vu_server, vu_opts->addr, exp->ctx,
+-                                 VHOST_USER_BLK_MAX_QUEUES, &vu_blk_iface,
+-                                 errp)) {
++                                 num_queues, &vu_blk_iface, errp)) {
+         blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
+                                         blk_aio_detach, vexp);
+         return -EADDRNOTAVAIL;
+--
+.26.2

-[Qemu-devel] [PULL 08/12] blockjob: group BlockJob transaction functions together
+[PULL v2 24/28] block/io: fix bdrv_co_block_status_above
-From: Paolo Bonzini <pbonzini@redhat.com>
+From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
-Yet another pure code movement patch, preparing for the next change.
+bdrv_co_block_status_above has several design problems with handling
 short backing files:
-Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+. With want_zeros=true, it may return ret with BDRV_BLOCK_ZERO but
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+without BDRV_BLOCK_ALLOCATED flag, when actually short backing file
-Message-id: 20170508141310.8674-9-pbonzini@redhat.com
+which produces these after-EOF zeros is inside requested backing
-Signed-off-by: Jeff Cody <jcody@redhat.com>
+sequence.
 . With want_zero=false, it may return pnum=0 prior to actual EOF,
 because of EOF of short backing file.
 Fix these things, making logic about short backing files clearer.
 With fixed bdrv_block_status_above we also have to improve is_zero in
 qcow2 code, otherwise iotest 154 will fail, because with this patch we
 stop to merge zeros of different types (produced by fully unallocated
 in the whole backing chain regions vs produced by short backing files).
 Note also, that this patch leaves for another day the general problem
 around block-status: misuse of BDRV_BLOCK_ALLOCATED as is-fs-allocated
 vs go-to-backing.
 Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
 Reviewed-by: Alberto Garcia <berto@igalia.com>
 Reviewed-by: Eric Blake <eblake@redhat.com>
 Message-id: 20200924194003.22080-2-vsementsov@virtuozzo.com
 [Fix s/comes/come/ as suggested by Eric Blake
 --Stefan]
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
- blockjob.c | 128 ++++++++++++++++++++++++++++++-------------------------------
+ block/io.c    | 68 ++++++++++++++++++++++++++++++++++++++++-----------
-file changed, 64 insertions(+), 64 deletions(-)
+ block/qcow2.c | 16 ++++++++++--
 files changed, 68 insertions(+), 16 deletions(-)
-diff --git a/blockjob.c b/blockjob.c
+diff --git a/block/io.c b/block/io.c
 index XXXXXXX..XXXXXXX 100644
---- a/blockjob.c
+--- a/block/io.c
-+++ b/blockjob.c
++++ b/block/io.c
-@@ -XXX,XX +XXX,XX @@ BlockJob *block_job_get(const char *id)
+@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
-     return NULL;
+                                   int64_t *map,
- }
+                                   BlockDriverState **file)
+ {
-+BlockJobTxn *block_job_txn_new(void)
++    int ret;
-+{
+     BlockDriverState *p;
-+    BlockJobTxn *txn = g_new0(BlockJobTxn, 1);
+-    int ret = 0;
-+    QLIST_INIT(&txn->jobs);
+-    bool first = true;
-+    txn->refcnt = 1;
++    int64_t eof = 0;
-+    return txn;
-+}
+     assert(bs != base);
 -    for (p = bs; p != base; p = bdrv_filter_or_cow_bs(p)) {
 +
-+static void block_job_txn_ref(BlockJobTxn *txn)
++    ret = bdrv_co_block_status(bs, want_zero, offset, bytes, pnum, map, file);
-+{
++    if (ret < 0 || *pnum == 0 || ret & BDRV_BLOCK_ALLOCATED) {
-+    txn->refcnt++;
++        return ret;
 +}
 +
 +void block_job_txn_unref(BlockJobTxn *txn)
 +{
 +    if (txn && --txn->refcnt == 0) {
 +        g_free(txn);
 +    }
 +}
 +
 +void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job)
 +{
 +    if (!txn) {
 +        return;
 +    }
 +
-+    assert(!job->txn);
++    if (ret & BDRV_BLOCK_EOF) {
-+    job->txn = txn;
++        eof = offset + *pnum;
 +    }
 +
-+    QLIST_INSERT_HEAD(&txn->jobs, job, txn_list);
++    assert(*pnum <= bytes);
-+    block_job_txn_ref(txn);
++    bytes = *pnum;
 +}
 +
- static void block_job_pause(BlockJob *job)
++    for (p = bdrv_filter_or_cow_bs(bs); p != base;
- {
++         p = bdrv_filter_or_cow_bs(p))
-     job->pause_count++;
++    {
-@@ -XXX,XX +XXX,XX @@ static void block_job_cancel_async(BlockJob *job)
+         ret = bdrv_co_block_status(p, want_zero, offset, bytes, pnum, map,
-     job->cancelled = true;
+                                    file);
          if (ret < 0) {
 -            break;
 +            return ret;
          }
 -        if (ret & BDRV_BLOCK_ZERO && ret & BDRV_BLOCK_EOF && !first) {
 +        if (*pnum == 0) {
              /*
 -             * Reading beyond the end of the file continues to read
 -             * zeroes, but we can only widen the result to the
 -             * unallocated length we learned from an earlier
 -             * iteration.
 +             * The top layer deferred to this layer, and because this layer is
 +             * short, any zeroes that we synthesize beyond EOF behave as if they
 +             * were allocated at this layer.
 +             *
 +             * We don't include BDRV_BLOCK_EOF into ret, as upper layer may be
 +             * larger. We'll add BDRV_BLOCK_EOF if needed at function end, see
 +             * below.
               */
 +            assert(ret & BDRV_BLOCK_EOF);
              *pnum = bytes;
 +            if (file) {
 +                *file = p;
 +            }
 +            ret = BDRV_BLOCK_ZERO | BDRV_BLOCK_ALLOCATED;
 +            break;
          }
 -        if (ret & (BDRV_BLOCK_ZERO | BDRV_BLOCK_DATA)) {
 +        if (ret & BDRV_BLOCK_ALLOCATED) {
 +            /*
 +             * We've found the node and the status, we must break.
 +             *
 +             * Drop BDRV_BLOCK_EOF, as it's not for upper layer, which may be
 +             * larger. We'll add BDRV_BLOCK_EOF if needed at function end, see
 +             * below.
 +             */
 +            ret &= ~BDRV_BLOCK_EOF;
              break;
          }
 -        /* [offset, pnum] unallocated on this layer, which could be only
 -         * the first part of [offset, bytes].  */
 -        bytes = MIN(bytes, *pnum);
 -        first = false;
 +
 +        /*
 +         * OK, [offset, offset + *pnum) region is unallocated on this layer,
 +         * let's continue the diving.
 +         */
 +        assert(*pnum <= bytes);
 +        bytes = *pnum;
 +    }
 +
 +    if (offset + *pnum == eof) {
 +        ret |= BDRV_BLOCK_EOF;
      }
 +
      return ret;
  }
-+static int block_job_finish_sync(BlockJob *job,
+diff --git a/block/qcow2.c b/block/qcow2.c
-+                                 void (*finish)(BlockJob *, Error **errp),
+index XXXXXXX..XXXXXXX 100644
-+                                 Error **errp)
+--- a/block/qcow2.c
-+{
++++ b/block/qcow2.c
-+    Error *local_err = NULL;
+@@ -XXX,XX +XXX,XX @@ static bool is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes)
-+    int ret;
+     if (!bytes) {
          return true;
      }
 -    res = bdrv_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL);
 -    return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == bytes;
 +
-+    assert(blk_bs(job->blk)->job == job);
++    /*
 +     * bdrv_block_status_above doesn't merge different types of zeros, for
 +     * example, zeros which come from the region which is unallocated in
 +     * the whole backing chain, and zeros which come because of a short
 +     * backing file. So, we need a loop.
 +     */
 +    do {
 +        res = bdrv_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL);
 +        offset += nr;
 +        bytes -= nr;
 +    } while (res >= 0 && (res & BDRV_BLOCK_ZERO) && nr && bytes);
 +
-+    block_job_ref(job);
++    return res >= 0 && (res & BDRV_BLOCK_ZERO) && bytes == 0;
 +
 +    finish(job, &local_err);
 +    if (local_err) {
 +        error_propagate(errp, local_err);
 +        block_job_unref(job);
 +        return -EBUSY;
 +    }
 +    /* block_job_drain calls block_job_enter, and it should be enough to
 +     * induce progress until the job completes or moves to the main thread.
 +    */
 +    while (!job->deferred_to_main_loop && !job->completed) {
 +        block_job_drain(job);
 +    }
 +    while (!job->completed) {
 +        aio_poll(qemu_get_aio_context(), true);
 +    }
 +    ret = (job->cancelled && job->ret == 0) ? -ECANCELED : job->ret;
 +    block_job_unref(job);
 +    return ret;
 +}
 +
  static void block_job_completed_txn_abort(BlockJob *job)
  {
      AioContext *ctx;
@@ -XXX,XX +XXX,XX @@ void block_job_cancel(BlockJob *job)
      }
  }
--static int block_job_finish_sync(BlockJob *job,
+ static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
 -                                 void (*finish)(BlockJob *, Error **errp),
 -                                 Error **errp)
 -{
 -    Error *local_err = NULL;
 -    int ret;
 -
 -    assert(blk_bs(job->blk)->job == job);
 -
 -    block_job_ref(job);
 -
 -    finish(job, &local_err);
 -    if (local_err) {
 -        error_propagate(errp, local_err);
 -        block_job_unref(job);
 -        return -EBUSY;
 -    }
 -    /* block_job_drain calls block_job_enter, and it should be enough to
 -     * induce progress until the job completes or moves to the main thread.
 -    */
 -    while (!job->deferred_to_main_loop && !job->completed) {
 -        block_job_drain(job);
 -    }
 -    while (!job->completed) {
 -        aio_poll(qemu_get_aio_context(), true);
 -    }
 -    ret = (job->cancelled && job->ret == 0) ? -ECANCELED : job->ret;
 -    block_job_unref(job);
 -    return ret;
 -}
 -
  /* A wrapper around block_job_cancel() taking an Error ** parameter so it may be
   * used with block_job_finish_sync() without the need for (rather nasty)
   * function pointer casts there. */
@@ -XXX,XX +XXX,XX @@ void block_job_defer_to_main_loop(BlockJob *job,
      aio_bh_schedule_oneshot(qemu_get_aio_context(),
                              block_job_defer_to_main_loop_bh, data);
  }
 -
 -BlockJobTxn *block_job_txn_new(void)
 -{
 -    BlockJobTxn *txn = g_new0(BlockJobTxn, 1);
 -    QLIST_INIT(&txn->jobs);
 -    txn->refcnt = 1;
 -    return txn;
 -}
 -
 -static void block_job_txn_ref(BlockJobTxn *txn)
 -{
 -    txn->refcnt++;
 -}
 -
 -void block_job_txn_unref(BlockJobTxn *txn)
 -{
 -    if (txn && --txn->refcnt == 0) {
 -        g_free(txn);
 -    }
 -}
 -
 -void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job)
 -{
 -    if (!txn) {
 -        return;
 -    }
 -
 -    assert(!job->txn);
 -    job->txn = txn;
 -
 -    QLIST_INSERT_HEAD(&txn->jobs, job, txn_list);
 -    block_job_txn_ref(txn);
 -}
 --
-.9.3
+.26.2

-[Qemu-devel] [PULL 02/12] blockjob: remove iostatus_reset callback
+[PULL v2 25/28] block/io: bdrv_common_block_status_above: support include_base
-From: Paolo Bonzini <pbonzini@redhat.com>
+From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
-This is unused since commit 66a0fae ("blockjob: Don't touch BDS iostatus",
+In order to reuse bdrv_common_block_status_above in
--05-19).
+bdrv_is_allocated_above, let's support include_base parameter.
-Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
-Reviewed-by: John Snow <jsnow@redhat.com>
+Reviewed-by: Alberto Garcia <berto@igalia.com>
-Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
+Reviewed-by: Eric Blake <eblake@redhat.com>
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Message-id: 20200924194003.22080-3-vsementsov@virtuozzo.com
-Reviewed-by: Jeff Cody <jcody@redhat.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 Message-id: 20170508141310.8674-3-pbonzini@redhat.com
 Signed-off-by: Jeff Cody <jcody@redhat.com>
 ---
- blockjob.c                   | 3 ---
+ block/coroutines.h |  2 ++
- include/block/blockjob_int.h | 3 ---
+ block/io.c         | 21 ++++++++++++++-------
-files changed, 6 deletions(-)
+files changed, 16 insertions(+), 7 deletions(-)
-diff --git a/blockjob.c b/blockjob.c
+diff --git a/block/coroutines.h b/block/coroutines.h
 index XXXXXXX..XXXXXXX 100644
---- a/blockjob.c
+--- a/block/coroutines.h
-+++ b/blockjob.c
++++ b/block/coroutines.h
-@@ -XXX,XX +XXX,XX @@ bool block_job_is_cancelled(BlockJob *job)
+@@ -XXX,XX +XXX,XX @@ bdrv_pwritev(BdrvChild *child, int64_t offset, unsigned int bytes,
- void block_job_iostatus_reset(BlockJob *job)
+ int coroutine_fn
  bdrv_co_common_block_status_above(BlockDriverState *bs,
                                    BlockDriverState *base,
 +                                  bool include_base,
                                    bool want_zero,
                                    int64_t offset,
                                    int64_t bytes,
@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
  int generated_co_wrapper
  bdrv_common_block_status_above(BlockDriverState *bs,
                                 BlockDriverState *base,
 +                               bool include_base,
                                 bool want_zero,
                                 int64_t offset,
                                 int64_t bytes,
 diff --git a/block/io.c b/block/io.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/io.c
 +++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ early_out:
  int coroutine_fn
  bdrv_co_common_block_status_above(BlockDriverState *bs,
                                    BlockDriverState *base,
 +                                  bool include_base,
                                    bool want_zero,
                                    int64_t offset,
                                    int64_t bytes,
@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
      BlockDriverState *p;
      int64_t eof = 0;
 -    assert(bs != base);
 +    assert(include_base || bs != base);
 +    assert(!include_base || base); /* Can't include NULL base */
      ret = bdrv_co_block_status(bs, want_zero, offset, bytes, pnum, map, file);
 -    if (ret < 0 || *pnum == 0 || ret & BDRV_BLOCK_ALLOCATED) {
 +    if (ret < 0 || *pnum == 0 || ret & BDRV_BLOCK_ALLOCATED || bs == base) {
          return ret;
      }
@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
      assert(*pnum <= bytes);
      bytes = *pnum;
 -    for (p = bdrv_filter_or_cow_bs(bs); p != base;
 +    for (p = bdrv_filter_or_cow_bs(bs); include_base || p != base;
           p = bdrv_filter_or_cow_bs(p))
      {
          ret = bdrv_co_block_status(p, want_zero, offset, bytes, pnum, map,
@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
              break;
          }
 +        if (p == base) {
 +            assert(include_base);
 +            break;
 +        }
 +
          /*
           * OK, [offset, offset + *pnum) region is unallocated on this layer,
           * let's continue the diving.
@@ -XXX,XX +XXX,XX @@ int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
                              int64_t offset, int64_t bytes, int64_t *pnum,
                              int64_t *map, BlockDriverState **file)
  {
-     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
+-    return bdrv_common_block_status_above(bs, base, true, offset, bytes,
--    if (job->driver->iostatus_reset) {
++    return bdrv_common_block_status_above(bs, base, false, true, offset, bytes,
--        job->driver->iostatus_reset(job);
+                                           pnum, map, file);
 -    }
  }
- static int block_job_finish_sync(BlockJob *job,
+@@ -XXX,XX +XXX,XX @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t offset,
-diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
+     int ret;
-index XXXXXXX..XXXXXXX 100644
+     int64_t dummy;
---- a/include/block/blockjob_int.h
-+++ b/include/block/blockjob_int.h
+-    ret = bdrv_common_block_status_above(bs, bdrv_filter_or_cow_bs(bs), false,
-@@ -XXX,XX +XXX,XX @@ struct BlockJobDriver {
+-                                         offset, bytes, pnum ? pnum : &dummy,
-     /** Optional callback for job types that support setting a speed limit */
+-                                         NULL, NULL);
-     void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
++    ret = bdrv_common_block_status_above(bs, bs, true, false, offset,
++                                         bytes, pnum ? pnum : &dummy, NULL,
--    /** Optional callback for job types that need to forward I/O status reset */
++                                         NULL);
--    void (*iostatus_reset)(BlockJob *job);
+     if (ret < 0) {
--
+         return ret;
-     /** Mandatory: Entrypoint for the Coroutine. */
+     }
      CoroutineEntry *start;
 --
-.9.3
+.26.2

-New patch
+[PULL v2 26/28] block/io: bdrv_common_block_status_above: support bs == base
+From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
+We are going to reuse bdrv_common_block_status_above in
+bdrv_is_allocated_above. bdrv_is_allocated_above may be called with
+include_base == false and still bs == base (for ex. from img_rebase()).
+So, support this corner case.
+Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
+Reviewed-by: Kevin Wolf <kwolf@redhat.com>
+Reviewed-by: Eric Blake <eblake@redhat.com>
+Reviewed-by: Alberto Garcia <berto@igalia.com>
+Message-id: 20200924194003.22080-4-vsementsov@virtuozzo.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ block/io.c | 6 +++++-
+file changed, 5 insertions(+), 1 deletion(-)
+diff --git a/block/io.c b/block/io.c
+index XXXXXXX..XXXXXXX 100644
+--- a/block/io.c
++++ b/block/io.c
+@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
+     BlockDriverState *p;
+     int64_t eof = 0;
+-    assert(include_base || bs != base);
+     assert(!include_base || base); /* Can't include NULL base */
++    if (!include_base && bs == base) {
++        *pnum = bytes;
++        return 0;
++    }
++
+     ret = bdrv_co_block_status(bs, want_zero, offset, bytes, pnum, map, file);
+     if (ret < 0 || *pnum == 0 || ret & BDRV_BLOCK_ALLOCATED || bs == base) {
+         return ret;
+--
+.26.2

-[Qemu-devel] [PULL 04/12] blockjob: introduce block_job_pause/resume_all
+[PULL v2 27/28] block/io: fix bdrv_is_allocated_above
-From: Paolo Bonzini <pbonzini@redhat.com>
+From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
-Remove use of block_job_pause/resume from outside blockjob.c, thus
+bdrv_is_allocated_above wrongly handles short backing files: it reports
-making them static.  The new functions are used by the block layer,
+after-EOF space as UNALLOCATED which is wrong, as on read the data is
-so place them in blockjob_int.h.
+generated on the level of short backing file (if all overlays have
 unallocated areas at that place).
-Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reusing bdrv_common_block_status_above fixes the issue and unifies code
-Reviewed-by: John Snow <jsnow@redhat.com>
+path.
-Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-Reviewed-by: Jeff Cody <jcody@redhat.com>
+Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
-Message-id: 20170508141310.8674-5-pbonzini@redhat.com
+Reviewed-by: Eric Blake <eblake@redhat.com>
-Signed-off-by: Jeff Cody <jcody@redhat.com>
+Reviewed-by: Alberto Garcia <berto@igalia.com>
 Message-id: 20200924194003.22080-5-vsementsov@virtuozzo.com
 [Fix s/has/have/ as suggested by Eric Blake. Fix s/area/areas/.
 --Stefan]
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
- block/io.c                   |  19 ++------
+ block/io.c | 43 +++++--------------------------------------
- blockjob.c                   | 114 ++++++++++++++++++++++++++-----------------
+file changed, 5 insertions(+), 38 deletions(-)
  include/block/blockjob.h     |  16 ------
  include/block/blockjob_int.h |  14 ++++++
 files changed, 86 insertions(+), 77 deletions(-)
 diff --git a/block/io.c b/block/io.c
 index XXXXXXX..XXXXXXX 100644
 --- a/block/io.c
 +++ b/block/io.c
-@@ -XXX,XX +XXX,XX @@
+@@ -XXX,XX +XXX,XX @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t offset,
- #include "trace.h"
+  * at 'offset + *pnum' may return the same allocation status (in other
- #include "sysemu/block-backend.h"
+  * words, the result is not necessarily the maximum possible range);
- #include "block/blockjob.h"
+  * but 'pnum' will only be 0 when end of file is reached.
-+#include "block/blockjob_int.h"
+- *
- #include "block/block_int.h"
+  */
- #include "qemu/cutils.h"
+ int bdrv_is_allocated_above(BlockDriverState *top,
- #include "qapi/error.h"
+                             BlockDriverState *base,
-@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
+                             bool include_base, int64_t offset,
-     bool waited = true;
+                             int64_t bytes, int64_t *pnum)
-     BlockDriverState *bs;
+ {
-     BdrvNextIterator it;
+-    BlockDriverState *intermediate;
--    BlockJob *job = NULL;
+-    int ret;
-     GSList *aio_ctxs = NULL, *ctx;
+-    int64_t n = bytes;
 -    while ((job = block_job_next(job))) {
 -        AioContext *aio_context = blk_get_aio_context(job->blk);
 -
--        aio_context_acquire(aio_context);
+-    assert(base || !include_base);
--        block_job_pause(job);
+-
--        aio_context_release(aio_context);
+-    intermediate = top;
--    }
+-    while (include_base || intermediate != base) {
-+    block_job_pause_all();
+-        int64_t pnum_inter;
+-        int64_t size_inter;
-     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+-
-         AioContext *aio_context = bdrv_get_aio_context(bs);
+-        assert(intermediate);
-@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
+-        ret = bdrv_is_allocated(intermediate, offset, bytes, &pnum_inter);
- {
+-        if (ret < 0) {
-     BlockDriverState *bs;
+-            return ret;
-     BdrvNextIterator it;
+-        }
--    BlockJob *job = NULL;
+-        if (ret) {
+-            *pnum = pnum_inter;
-     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
+-            return 1;
-         AioContext *aio_context = bdrv_get_aio_context(bs);
+-        }
-@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
+-
-         aio_context_release(aio_context);
+-        size_inter = bdrv_getlength(intermediate);
 -        if (size_inter < 0) {
 -            return size_inter;
 -        }
 -        if (n > pnum_inter &&
 -            (intermediate == top || offset + pnum_inter < size_inter)) {
 -            n = pnum_inter;
 -        }
 -
 -        if (intermediate == base) {
 -            break;
 -        }
 -
 -        intermediate = bdrv_filter_or_cow_bs(intermediate);
 +    int ret = bdrv_common_block_status_above(top, base, include_base, false,
 +                                             offset, bytes, pnum, NULL, NULL);
 +    if (ret < 0) {
 +        return ret;
      }
--    while ((job = block_job_next(job))) {
+-    *pnum = n;
--        AioContext *aio_context = blk_get_aio_context(job->blk);
+-    return 0;
--
++    return !!(ret & BDRV_BLOCK_ALLOCATED);
 -        aio_context_acquire(aio_context);
 -        block_job_resume(job);
 -        aio_context_release(aio_context);
 -    }
 +    block_job_resume_all();
  }
- void bdrv_drain_all(void)
+ int coroutine_fn
 diff --git a/blockjob.c b/blockjob.c
 index XXXXXXX..XXXXXXX 100644
 --- a/blockjob.c
 +++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ struct BlockJobTxn {
  static QLIST_HEAD(, BlockJob) block_jobs = QLIST_HEAD_INITIALIZER(block_jobs);
 -static char *child_job_get_parent_desc(BdrvChild *c)
 -{
 -    BlockJob *job = c->opaque;
 -    return g_strdup_printf("%s job '%s'",
 -                           BlockJobType_lookup[job->driver->job_type],
 -                           job->id);
 -}
 -
 -static const BdrvChildRole child_job = {
 -    .get_parent_desc    = child_job_get_parent_desc,
 -    .stay_at_node       = true,
 -};
 -
 -static void block_job_drained_begin(void *opaque)
 -{
 -    BlockJob *job = opaque;
 -    block_job_pause(job);
 -}
 -
 -static void block_job_drained_end(void *opaque)
 -{
 -    BlockJob *job = opaque;
 -    block_job_resume(job);
 -}
 -
 -static const BlockDevOps block_job_dev_ops = {
 -    .drained_begin = block_job_drained_begin,
 -    .drained_end = block_job_drained_end,
 -};
 -
  BlockJob *block_job_next(BlockJob *job)
  {
      if (!job) {
@@ -XXX,XX +XXX,XX @@ BlockJob *block_job_get(const char *id)
      return NULL;
  }
 +static void block_job_pause(BlockJob *job)
 +{
 +    job->pause_count++;
 +}
 +
 +static void block_job_resume(BlockJob *job)
 +{
 +    assert(job->pause_count > 0);
 +    job->pause_count--;
 +    if (job->pause_count) {
 +        return;
 +    }
 +    block_job_enter(job);
 +}
 +
  static void block_job_ref(BlockJob *job)
  {
      ++job->refcnt;
@@ -XXX,XX +XXX,XX @@ static void block_job_detach_aio_context(void *opaque)
      block_job_unref(job);
  }
 +static char *child_job_get_parent_desc(BdrvChild *c)
 +{
 +    BlockJob *job = c->opaque;
 +    return g_strdup_printf("%s job '%s'",
 +                           BlockJobType_lookup[job->driver->job_type],
 +                           job->id);
 +}
 +
 +static const BdrvChildRole child_job = {
 +    .get_parent_desc    = child_job_get_parent_desc,
 +    .stay_at_node       = true,
 +};
 +
 +static void block_job_drained_begin(void *opaque)
 +{
 +    BlockJob *job = opaque;
 +    block_job_pause(job);
 +}
 +
 +static void block_job_drained_end(void *opaque)
 +{
 +    BlockJob *job = opaque;
 +    block_job_resume(job);
 +}
 +
 +static const BlockDevOps block_job_dev_ops = {
 +    .drained_begin = block_job_drained_begin,
 +    .drained_end = block_job_drained_end,
 +};
 +
  void block_job_remove_all_bdrv(BlockJob *job)
  {
      GSList *l;
@@ -XXX,XX +XXX,XX @@ void block_job_complete(BlockJob *job, Error **errp)
      job->driver->complete(job, errp);
  }
 -void block_job_pause(BlockJob *job)
 -{
 -    job->pause_count++;
 -}
 -
  void block_job_user_pause(BlockJob *job)
  {
      job->user_paused = true;
@@ -XXX,XX +XXX,XX @@ void coroutine_fn block_job_pause_point(BlockJob *job)
      }
  }
 -void block_job_resume(BlockJob *job)
 -{
 -    assert(job->pause_count > 0);
 -    job->pause_count--;
 -    if (job->pause_count) {
 -        return;
 -    }
 -    block_job_enter(job);
 -}
 -
  void block_job_user_resume(BlockJob *job)
  {
      if (job && job->user_paused && job->pause_count > 0) {
@@ -XXX,XX +XXX,XX @@ static void block_job_event_completed(BlockJob *job, const char *msg)
                                          &error_abort);
  }
 +void block_job_pause_all(void)
 +{
 +    BlockJob *job = NULL;
 +    while ((job = block_job_next(job))) {
 +        AioContext *aio_context = blk_get_aio_context(job->blk);
 +
 +        aio_context_acquire(aio_context);
 +        block_job_pause(job);
 +        aio_context_release(aio_context);
 +    }
 +}
 +
 +void block_job_resume_all(void)
 +{
 +    BlockJob *job = NULL;
 +    while ((job = block_job_next(job))) {
 +        AioContext *aio_context = blk_get_aio_context(job->blk);
 +
 +        aio_context_acquire(aio_context);
 +        block_job_resume(job);
 +        aio_context_release(aio_context);
 +    }
 +}
 +
  void block_job_event_ready(BlockJob *job)
  {
      job->ready = true;
 diff --git a/include/block/blockjob.h b/include/block/blockjob.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/block/blockjob.h
 +++ b/include/block/blockjob.h
@@ -XXX,XX +XXX,XX @@ void block_job_complete(BlockJob *job, Error **errp);
  BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
  /**
 - * block_job_pause:
 - * @job: The job to be paused.
 - *
 - * Asynchronously pause the specified job.
 - */
 -void block_job_pause(BlockJob *job);
 -
 -/**
   * block_job_user_pause:
   * @job: The job to be paused.
   *
@@ -XXX,XX +XXX,XX @@ void block_job_user_pause(BlockJob *job);
  bool block_job_user_paused(BlockJob *job);
  /**
 - * block_job_resume:
 - * @job: The job to be resumed.
 - *
 - * Resume the specified job.  Must be paired with a preceding block_job_pause.
 - */
 -void block_job_resume(BlockJob *job);
 -
 -/**
   * block_job_user_resume:
   * @job: The job to be resumed.
   *
 diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/block/blockjob_int.h
 +++ b/include/block/blockjob_int.h
@@ -XXX,XX +XXX,XX @@ void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns);
  void block_job_yield(BlockJob *job);
  /**
 + * block_job_pause_all:
 + *
 + * Asynchronously pause all jobs.
 + */
 +void block_job_pause_all(void);
 +
 +/**
 + * block_job_resume_all:
 + *
 + * Resume all block jobs.  Must be paired with a preceding block_job_pause_all.
 + */
 +void block_job_resume_all(void);
 +
 +/**
   * block_job_early_fail:
   * @bs: The block device.
   *
 --
-.9.3
+.26.2

-[Qemu-devel] [PULL 12/12] block/gluster: glfs_lseek() workaround
+[PULL v2 28/28] iotests: add commit top->base cases to 274
-On current released versions of glusterfs, glfs_lseek() will sometimes
+From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
 return invalid values for SEEK_DATA or SEEK_HOLE.  For SEEK_DATA and
 SEEK_HOLE, the returned value should be >= the passed offset, or < 0 in
 the case of error:
-LSEEK(2):
+These cases are fixed by previous patches around block_status and
 is_allocated.
-    off_t lseek(int fd, off_t offset, int whence);
+Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
 Reviewed-by: Eric Blake <eblake@redhat.com>
 Reviewed-by: Alberto Garcia <berto@igalia.com>
 Message-id: 20200924194003.22080-6-vsementsov@virtuozzo.com
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
  tests/qemu-iotests/274     | 20 +++++++++++
  tests/qemu-iotests/274.out | 68 ++++++++++++++++++++++++++++++++++++++
 files changed, 88 insertions(+)
-    [...]
+diff --git a/tests/qemu-iotests/274 b/tests/qemu-iotests/274
 index XXXXXXX..XXXXXXX 100755
 --- a/tests/qemu-iotests/274
 +++ b/tests/qemu-iotests/274
@@ -XXX,XX +XXX,XX @@ with iotests.FilePath('base') as base, \
      iotests.qemu_io_log('-c', 'read -P 1 0 %d' % size_short, mid)
      iotests.qemu_io_log('-c', 'read -P 0 %d %d' % (size_short, size_diff), mid)
 +    iotests.log('=== Testing qemu-img commit (top -> base) ===')
 +
 +    create_chain()
 +    iotests.qemu_img_log('commit', '-b', base, top)
 +    iotests.img_info_log(base)
 +    iotests.qemu_io_log('-c', 'read -P 1 0 %d' % size_short, base)
 +    iotests.qemu_io_log('-c', 'read -P 0 %d %d' % (size_short, size_diff), base)
 +
 +    iotests.log('=== Testing QMP active commit (top -> base) ===')
 +
 +    create_chain()
 +    with create_vm() as vm:
 +        vm.launch()
 +        vm.qmp_log('block-commit', device='top', base_node='base',
 +                   job_id='job0', auto_dismiss=False)
 +        vm.run_job('job0', wait=5)
 +
 +    iotests.img_info_log(mid)
 +    iotests.qemu_io_log('-c', 'read -P 1 0 %d' % size_short, base)
 +    iotests.qemu_io_log('-c', 'read -P 0 %d %d' % (size_short, size_diff), base)
      iotests.log('== Resize tests ==')
 diff --git a/tests/qemu-iotests/274.out b/tests/qemu-iotests/274.out
 index XXXXXXX..XXXXXXX 100644
 --- a/tests/qemu-iotests/274.out
 +++ b/tests/qemu-iotests/274.out
@@ -XXX,XX +XXX,XX @@ read 1048576/1048576 bytes at offset 0
  read 1048576/1048576 bytes at offset 1048576
 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 +=== Testing qemu-img commit (top -> base) ===
 +Formatting 'TEST_DIR/PID-base', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=2097152 lazy_refcounts=off refcount_bits=16
 +
 +Formatting 'TEST_DIR/PID-mid', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=1048576 backing_file=TEST_DIR/PID-base backing_fmt=qcow2 lazy_refcounts=off refcount_bits=16
 +
 +Formatting 'TEST_DIR/PID-top', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=2097152 backing_file=TEST_DIR/PID-mid backing_fmt=qcow2 lazy_refcounts=off refcount_bits=16
 +
 +wrote 2097152/2097152 bytes at offset 0
 +2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 +
 +Image committed.
 +
 +image: TEST_IMG
 +file format: IMGFMT
 +virtual size: 2 MiB (2097152 bytes)
 +cluster_size: 65536
 +Format specific information:
 +    compat: 1.1
 +    compression type: zlib
 +    lazy refcounts: false
 +    refcount bits: 16
 +    corrupt: false
 +    extended l2: false
 +
 +read 1048576/1048576 bytes at offset 0
 +1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 +
 +read 1048576/1048576 bytes at offset 1048576
 +1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 +
 +=== Testing QMP active commit (top -> base) ===
 +Formatting 'TEST_DIR/PID-base', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=2097152 lazy_refcounts=off refcount_bits=16
 +
 +Formatting 'TEST_DIR/PID-mid', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=1048576 backing_file=TEST_DIR/PID-base backing_fmt=qcow2 lazy_refcounts=off refcount_bits=16
 +
 +Formatting 'TEST_DIR/PID-top', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=2097152 backing_file=TEST_DIR/PID-mid backing_fmt=qcow2 lazy_refcounts=off refcount_bits=16
 +
 +wrote 2097152/2097152 bytes at offset 0
 +2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 +
 +{"execute": "block-commit", "arguments": {"auto-dismiss": false, "base-node": "base", "device": "top", "job-id": "job0"}}
 +{"return": {}}
 +{"execute": "job-complete", "arguments": {"id": "job0"}}
 +{"return": {}}
 +{"data": {"device": "job0", "len": 1048576, "offset": 1048576, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_READY", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 +{"data": {"device": "job0", "len": 1048576, "offset": 1048576, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 +{"execute": "job-dismiss", "arguments": {"id": "job0"}}
 +{"return": {}}
 +image: TEST_IMG
 +file format: IMGFMT
 +virtual size: 1 MiB (1048576 bytes)
 +cluster_size: 65536
 +backing file: TEST_DIR/PID-base
 +backing file format: IMGFMT
 +Format specific information:
 +    compat: 1.1
 +    compression type: zlib
 +    lazy refcounts: false
 +    refcount bits: 16
 +    corrupt: false
 +    extended l2: false
 +
 +read 1048576/1048576 bytes at offset 0
 +1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 +
 +read 1048576/1048576 bytes at offset 1048576
 +1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 +
  == Resize tests ==
  === preallocation=off ===
  Formatting 'TEST_DIR/PID-base', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=6442450944 lazy_refcounts=off refcount_bits=16
 --
 .26.2
-    SEEK_HOLE
-              Adjust  the file offset to the next hole in the file greater
-              than or equal to offset.  If offset points into the middle of
-              a hole, then the file offset is set to offset.  If there is no
-              hole past offset, then the file offset is adjusted to the end
-              of the file (i.e., there is  an implicit hole at the end of
-              any file).
-    [...]
-    RETURN VALUE
-              Upon  successful  completion,  lseek()  returns  the resulting
-              offset location as measured in bytes from the beginning of the
-              file.  On error, the value (off_t) -1 is returned and errno is
-              set to indicate the error
-However, occasionally glfs_lseek() for SEEK_HOLE/DATA will return a
-value less than the passed offset, yet greater than zero.
-For instance, here are example values observed from this call:
-    offs = glfs_lseek(s->fd, start, SEEK_HOLE);
-    if (offs < 0) {
-        return -errno;          /* D1 and (H3 or H4) */
-    }
-start == 7608336384
-offs == 7607877632
-This causes QEMU to abort on the assert test.  When this value is
-returned, errno is also 0.
-This is a reported and known bug to glusterfs:
-https://bugzilla.redhat.com/show_bug.cgi?id=1425293
-Although this is being fixed in gluster, we still should work around it
-in QEMU, given that multiple released versions of gluster behave this
-way.
-This patch treats the return case of (offs < start) the same as if an
-error value other than ENXIO is returned; we will assume we learned
-nothing, and there are no holes in the file.
-Signed-off-by: Jeff Cody <jcody@redhat.com>
-Reviewed-by: Eric Blake <eblake@redhat.com>
-Reviewed-by: Niels de Vos <ndevos@redhat.com>
-Message-id: 87c0140e9407c08f6e74b04131b610f2e27c014c.1495560397.git.jcody@redhat.com
-Signed-off-by: Jeff Cody <jcody@redhat.com>
----
- block/gluster.c | 18 ++++++++++++++++--
-file changed, 16 insertions(+), 2 deletions(-)
-diff --git a/block/gluster.c b/block/gluster.c
-index XXXXXXX..XXXXXXX 100644
---- a/block/gluster.c
-+++ b/block/gluster.c
-@@ -XXX,XX +XXX,XX @@ static int find_allocation(BlockDriverState *bs, off_t start,
-     if (offs < 0) {
-         return -errno;          /* D3 or D4 */
-     }
--    assert(offs >= start);
-+
-+    if (offs < start) {
-+        /* This is not a valid return by lseek().  We are safe to just return
-+         * -EIO in this case, and we'll treat it like D4. Unfortunately some
-+         *  versions of gluster server will return offs < start, so an assert
-+         *  here will unnecessarily abort QEMU. */
-+        return -EIO;
-+    }
-     if (offs > start) {
-         /* D2: in hole, next data at offs */
-@@ -XXX,XX +XXX,XX @@ static int find_allocation(BlockDriverState *bs, off_t start,
-     if (offs < 0) {
-         return -errno;          /* D1 and (H3 or H4) */
-     }
--    assert(offs >= start);
-+
-+    if (offs < start) {
-+        /* This is not a valid return by lseek().  We are safe to just return
-+         * -EIO in this case, and we'll treat it like H4. Unfortunately some
-+         *  versions of gluster server will return offs < start, so an assert
-+         *  here will unnecessarily abort QEMU. */
-+        return -EIO;
-+    }
-     if (offs > start) {
-         /*
---
-.9.3

The following changes since commit 9964e96dc9999cf7f7c936ee854a795415d19b60:

Merge remote-tracking branch 'jasowang/tags/net-pull-request' into staging (2017-05-23 15:01:31 +0100)

are available in the git repository at:

git://github.com/codyprime/qemu-kvm-jtc.git tags/block-pull-request

for you to fetch changes up to 223a23c198787328ae75bc65d84edf5fde33c0b6:

block/gluster: glfs_lseek() workaround (2017-05-24 16:44:46 -0400)

----------------------------------------------------------------
Block patches
----------------------------------------------------------------

Jeff Cody (1):
  block/gluster: glfs_lseek() workaround

Paolo Bonzini (11):
  blockjob: remove unnecessary check
  blockjob: remove iostatus_reset callback
  blockjob: introduce block_job_early_fail
  blockjob: introduce block_job_pause/resume_all
  blockjob: separate monitor and blockjob APIs
  blockjob: move iostatus reset inside block_job_user_resume
  blockjob: introduce block_job_cancel_async, check iostatus invariants
  blockjob: group BlockJob transaction functions together
  blockjob: strengthen a bit test-blockjob-txn
  blockjob: reorganize block_job_completed_txn_abort
  blockjob: use deferred_to_main_loop to indicate the coroutine has
    ended

-- 
2.9.3

From: Paolo Bonzini <pbonzini@redhat.com>

This is unused since commit 66a0fae ("blockjob: Don't touch BDS iostatus",
2016-05-19).

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20170508141310.8674-3-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 blockjob.c                   | 3 ---
 include/block/blockjob_int.h | 3 ---
 2 files changed, 6 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ bool block_job_is_cancelled(BlockJob *job)
 void block_job_iostatus_reset(BlockJob *job)
 {
     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
-    if (job->driver->iostatus_reset) {
-        job->driver->iostatus_reset(job);
-    }
 }
 
 static int block_job_finish_sync(BlockJob *job,
diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/blockjob_int.h
+++ b/include/block/blockjob_int.h
@@ -XXX,XX +XXX,XX @@ struct BlockJobDriver {
     /** Optional callback for job types that support setting a speed limit */
     void (*set_speed)(BlockJob *job, int64_t speed, Error **errp);
 
-    /** Optional callback for job types that need to forward I/O status reset */
-    void (*iostatus_reset)(BlockJob *job);
-
     /** Mandatory: Entrypoint for the Coroutine. */
     CoroutineEntry *start;
 
-- 
2.9.3

From: Paolo Bonzini <pbonzini@redhat.com>

Outside blockjob.c, block_job_unref is only used when a block job fails
to start, and block_job_ref is not used at all.  The reference counting
thus is pretty well hidden.  Introduce a separate function to be used
by block jobs; because block_job_ref and block_job_unref now become
static, move them earlier in blockjob.c.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20170508141310.8674-4-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 block/backup.c               |  2 +-
 block/commit.c               |  2 +-
 block/mirror.c               |  2 +-
 blockjob.c                   | 47 ++++++++++++++++++++++++++------------------
 include/block/blockjob_int.h | 15 +++-----------
 tests/test-blockjob.c        | 10 +++++-----
 6 files changed, 39 insertions(+), 39 deletions(-)

diff --git a/block/backup.c b/block/backup.c
index XXXXXXX..XXXXXXX 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -XXX,XX +XXX,XX @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
     }
     if (job) {
         backup_clean(&job->common);
-        block_job_unref(&job->common);
+        block_job_early_fail(&job->common);
     }
 
     return NULL;
diff --git a/block/commit.c b/block/commit.c
index XXXXXXX..XXXXXXX 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -XXX,XX +XXX,XX @@ fail:
     if (commit_top_bs) {
         bdrv_set_backing_hd(overlay_bs, top, &error_abort);
     }
-    block_job_unref(&s->common);
+    block_job_early_fail(&s->common);
 }
 
 
diff --git a/block/mirror.c b/block/mirror.c
index XXXXXXX..XXXXXXX 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -XXX,XX +XXX,XX @@ fail:
 
         g_free(s->replaces);
         blk_unref(s->target);
-        block_job_unref(&s->common);
+        block_job_early_fail(&s->common);
     }
 
     bdrv_child_try_set_perm(mirror_top_bs->backing, 0, BLK_PERM_ALL,
diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ BlockJob *block_job_get(const char *id)
     return NULL;
 }
 
+static void block_job_ref(BlockJob *job)
+{
+    ++job->refcnt;
+}
+
+static void block_job_attached_aio_context(AioContext *new_context,
+                                           void *opaque);
+static void block_job_detach_aio_context(void *opaque);
+
+static void block_job_unref(BlockJob *job)
+{
+    if (--job->refcnt == 0) {
+        BlockDriverState *bs = blk_bs(job->blk);
+        bs->job = NULL;
+        block_job_remove_all_bdrv(job);
+        blk_remove_aio_context_notifier(job->blk,
+                                        block_job_attached_aio_context,
+                                        block_job_detach_aio_context, job);
+        blk_unref(job->blk);
+        error_free(job->blocker);
+        g_free(job->id);
+        QLIST_REMOVE(job, job_list);
+        g_free(job);
+    }
+}
+
 static void block_job_attached_aio_context(AioContext *new_context,
                                            void *opaque)
 {
@@ -XXX,XX +XXX,XX @@ void block_job_start(BlockJob *job)
     bdrv_coroutine_enter(blk_bs(job->blk), job->co);
 }
 
-void block_job_ref(BlockJob *job)
+void block_job_early_fail(BlockJob *job)
 {
-    ++job->refcnt;
-}
-
-void block_job_unref(BlockJob *job)
-{
-    if (--job->refcnt == 0) {
-        BlockDriverState *bs = blk_bs(job->blk);
-        bs->job = NULL;
-        block_job_remove_all_bdrv(job);
-        blk_remove_aio_context_notifier(job->blk,
-                                        block_job_attached_aio_context,
-                                        block_job_detach_aio_context, job);
-        blk_unref(job->blk);
-        error_free(job->blocker);
-        g_free(job->id);
-        QLIST_REMOVE(job, job_list);
-        g_free(job);
-    }
+    block_job_unref(job);
 }
 
 static void block_job_completed_single(BlockJob *job)
diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/blockjob_int.h
+++ b/include/block/blockjob_int.h
@@ -XXX,XX +XXX,XX @@ void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns);
 void block_job_yield(BlockJob *job);
 
 /**
- * block_job_ref:
+ * block_job_early_fail:
  * @bs: The block device.
  *
- * Grab a reference to the block job. Should be paired with block_job_unref.
+ * The block job could not be started, free it.
  */
-void block_job_ref(BlockJob *job);
-
-/**
- * block_job_unref:
- * @bs: The block device.
- *
- * Release reference to the block job and release resources if it is the last
- * reference.
- */
-void block_job_unref(BlockJob *job);
+void block_job_early_fail(BlockJob *job);
 
 /**
  * block_job_completed:
diff --git a/tests/test-blockjob.c b/tests/test-blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-blockjob.c
+++ b/tests/test-blockjob.c
@@ -XXX,XX +XXX,XX @@ static void test_job_ids(void)
     job[1] = do_test_id(blk[1], "id0", false);
 
     /* But once job[0] finishes we can reuse its ID */
-    block_job_unref(job[0]);
+    block_job_early_fail(job[0]);
     job[1] = do_test_id(blk[1], "id0", true);
 
     /* No job ID specified, defaults to the backend name ('drive1') */
-    block_job_unref(job[1]);
+    block_job_early_fail(job[1]);
     job[1] = do_test_id(blk[1], NULL, true);
 
     /* Duplicate job ID */
@@ -XXX,XX +XXX,XX @@ static void test_job_ids(void)
     /* This one is valid */
     job[2] = do_test_id(blk[2], "id_2", true);
 
-    block_job_unref(job[0]);
-    block_job_unref(job[1]);
-    block_job_unref(job[2]);
+    block_job_early_fail(job[0]);
+    block_job_early_fail(job[1]);
+    block_job_early_fail(job[2]);
 
     destroy_blk(blk[0]);
     destroy_blk(blk[1]);
-- 
2.9.3

From: Paolo Bonzini <pbonzini@redhat.com>

Remove use of block_job_pause/resume from outside blockjob.c, thus
making them static.  The new functions are used by the block layer,
so place them in blockjob_int.h.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20170508141310.8674-5-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 block/io.c                   |  19 ++------
 blockjob.c                   | 114 ++++++++++++++++++++++++++-----------------
 include/block/blockjob.h     |  16 ------
 include/block/blockjob_int.h |  14 ++++++
 4 files changed, 86 insertions(+), 77 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@
 #include "trace.h"
 #include "sysemu/block-backend.h"
 #include "block/blockjob.h"
+#include "block/blockjob_int.h"
 #include "block/block_int.h"
 #include "qemu/cutils.h"
 #include "qapi/error.h"
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_begin(void)
     bool waited = true;
     BlockDriverState *bs;
     BdrvNextIterator it;
-    BlockJob *job = NULL;
     GSList *aio_ctxs = NULL, *ctx;
 
-    while ((job = block_job_next(job))) {
-        AioContext *aio_context = blk_get_aio_context(job->blk);
-
-        aio_context_acquire(aio_context);
-        block_job_pause(job);
-        aio_context_release(aio_context);
-    }
+    block_job_pause_all();
 
     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
         AioContext *aio_context = bdrv_get_aio_context(bs);
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
 {
     BlockDriverState *bs;
     BdrvNextIterator it;
-    BlockJob *job = NULL;
 
     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
         AioContext *aio_context = bdrv_get_aio_context(bs);
@@ -XXX,XX +XXX,XX @@ void bdrv_drain_all_end(void)
         aio_context_release(aio_context);
     }
 
-    while ((job = block_job_next(job))) {
-        AioContext *aio_context = blk_get_aio_context(job->blk);
-
-        aio_context_acquire(aio_context);
-        block_job_resume(job);
-        aio_context_release(aio_context);
-    }
+    block_job_resume_all();
 }
 
 void bdrv_drain_all(void)
diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ struct BlockJobTxn {
 
 static QLIST_HEAD(, BlockJob) block_jobs = QLIST_HEAD_INITIALIZER(block_jobs);
 
-static char *child_job_get_parent_desc(BdrvChild *c)
-{
-    BlockJob *job = c->opaque;
-    return g_strdup_printf("%s job '%s'",
-                           BlockJobType_lookup[job->driver->job_type],
-                           job->id);
-}
-
-static const BdrvChildRole child_job = {
-    .get_parent_desc    = child_job_get_parent_desc,
-    .stay_at_node       = true,
-};
-
-static void block_job_drained_begin(void *opaque)
-{
-    BlockJob *job = opaque;
-    block_job_pause(job);
-}
-
-static void block_job_drained_end(void *opaque)
-{
-    BlockJob *job = opaque;
-    block_job_resume(job);
-}
-
-static const BlockDevOps block_job_dev_ops = {
-    .drained_begin = block_job_drained_begin,
-    .drained_end = block_job_drained_end,
-};
-
 BlockJob *block_job_next(BlockJob *job)
 {
     if (!job) {
@@ -XXX,XX +XXX,XX @@ BlockJob *block_job_get(const char *id)
     return NULL;
 }
 
+static void block_job_pause(BlockJob *job)
+{
+    job->pause_count++;
+}
+
+static void block_job_resume(BlockJob *job)
+{
+    assert(job->pause_count > 0);
+    job->pause_count--;
+    if (job->pause_count) {
+        return;
+    }
+    block_job_enter(job);
+}
+
 static void block_job_ref(BlockJob *job)
 {
     ++job->refcnt;
@@ -XXX,XX +XXX,XX @@ static void block_job_detach_aio_context(void *opaque)
     block_job_unref(job);
 }
 
+static char *child_job_get_parent_desc(BdrvChild *c)
+{
+    BlockJob *job = c->opaque;
+    return g_strdup_printf("%s job '%s'",
+                           BlockJobType_lookup[job->driver->job_type],
+                           job->id);
+}
+
+static const BdrvChildRole child_job = {
+    .get_parent_desc    = child_job_get_parent_desc,
+    .stay_at_node       = true,
+};
+
+static void block_job_drained_begin(void *opaque)
+{
+    BlockJob *job = opaque;
+    block_job_pause(job);
+}
+
+static void block_job_drained_end(void *opaque)
+{
+    BlockJob *job = opaque;
+    block_job_resume(job);
+}
+
+static const BlockDevOps block_job_dev_ops = {
+    .drained_begin = block_job_drained_begin,
+    .drained_end = block_job_drained_end,
+};
+
 void block_job_remove_all_bdrv(BlockJob *job)
 {
     GSList *l;
@@ -XXX,XX +XXX,XX @@ void block_job_complete(BlockJob *job, Error **errp)
     job->driver->complete(job, errp);
 }
 
-void block_job_pause(BlockJob *job)
-{
-    job->pause_count++;
-}
-
 void block_job_user_pause(BlockJob *job)
 {
     job->user_paused = true;
@@ -XXX,XX +XXX,XX @@ void coroutine_fn block_job_pause_point(BlockJob *job)
     }
 }
 
-void block_job_resume(BlockJob *job)
-{
-    assert(job->pause_count > 0);
-    job->pause_count--;
-    if (job->pause_count) {
-        return;
-    }
-    block_job_enter(job);
-}
-
 void block_job_user_resume(BlockJob *job)
 {
     if (job && job->user_paused && job->pause_count > 0) {
@@ -XXX,XX +XXX,XX @@ static void block_job_event_completed(BlockJob *job, const char *msg)
                                         &error_abort);
 }
 
+void block_job_pause_all(void)
+{
+    BlockJob *job = NULL;
+    while ((job = block_job_next(job))) {
+        AioContext *aio_context = blk_get_aio_context(job->blk);
+
+        aio_context_acquire(aio_context);
+        block_job_pause(job);
+        aio_context_release(aio_context);
+    }
+}
+
+void block_job_resume_all(void)
+{
+    BlockJob *job = NULL;
+    while ((job = block_job_next(job))) {
+        AioContext *aio_context = blk_get_aio_context(job->blk);
+
+        aio_context_acquire(aio_context);
+        block_job_resume(job);
+        aio_context_release(aio_context);
+    }
+}
+
 void block_job_event_ready(BlockJob *job)
 {
     job->ready = true;
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -XXX,XX +XXX,XX @@ void block_job_complete(BlockJob *job, Error **errp);
 BlockJobInfo *block_job_query(BlockJob *job, Error **errp);
 
 /**
- * block_job_pause:
- * @job: The job to be paused.
- *
- * Asynchronously pause the specified job.
- */
-void block_job_pause(BlockJob *job);
-
-/**
  * block_job_user_pause:
  * @job: The job to be paused.
  *
@@ -XXX,XX +XXX,XX @@ void block_job_user_pause(BlockJob *job);
 bool block_job_user_paused(BlockJob *job);
 
 /**
- * block_job_resume:
- * @job: The job to be resumed.
- *
- * Resume the specified job.  Must be paired with a preceding block_job_pause.
- */
-void block_job_resume(BlockJob *job);
-
-/**
  * block_job_user_resume:
  * @job: The job to be resumed.
  *
diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/blockjob_int.h
+++ b/include/block/blockjob_int.h
@@ -XXX,XX +XXX,XX @@ void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns);
 void block_job_yield(BlockJob *job);
 
 /**
+ * block_job_pause_all:
+ *
+ * Asynchronously pause all jobs.
+ */
+void block_job_pause_all(void);
+
+/**
+ * block_job_resume_all:
+ *
+ * Resume all block jobs.  Must be paired with a preceding block_job_pause_all.
+ */
+void block_job_resume_all(void);
+
+/**
  * block_job_early_fail:
  * @bs: The block device.
  *
-- 
2.9.3

From: Paolo Bonzini <pbonzini@redhat.com>

We have two different headers for block job operations, blockjob.h
and blockjob_int.h.  The former contains APIs called by the monitor,
the latter contains APIs called by the block job drivers and the
block layer itself.

Keep the two APIs separate in the blockjob.c file too.  This will
be useful when transitioning away from the AioContext lock, because
there will be locking policies for the two categories, too---the
monitor will have to call new block_job_lock/unlock APIs, while blockjob
APIs will take care of this for the users.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170508141310.8674-6-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 blockjob.c | 390 ++++++++++++++++++++++++++++++++-----------------------------
 1 file changed, 205 insertions(+), 185 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ struct BlockJobTxn {
 
 static QLIST_HEAD(, BlockJob) block_jobs = QLIST_HEAD_INITIALIZER(block_jobs);
 
+/*
+ * The block job API is composed of two categories of functions.
+ *
+ * The first includes functions used by the monitor.  The monitor is
+ * peculiar in that it accesses the block job list with block_job_get, and
+ * therefore needs consistency across block_job_get and the actual operation
+ * (e.g. block_job_set_speed).  The consistency is achieved with
+ * aio_context_acquire/release.  These functions are declared in blockjob.h.
+ *
+ * The second includes functions used by the block job drivers and sometimes
+ * by the core block layer.  These do not care about locking, because the
+ * whole coroutine runs under the AioContext lock, and are declared in
+ * blockjob_int.h.
+ */
+
 BlockJob *block_job_next(BlockJob *job)
 {
     if (!job) {
@@ -XXX,XX +XXX,XX @@ int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs,
     return 0;
 }
 
-void *block_job_create(const char *job_id, const BlockJobDriver *driver,
-                       BlockDriverState *bs, uint64_t perm,
-                       uint64_t shared_perm, int64_t speed, int flags,
-                       BlockCompletionFunc *cb, void *opaque, Error **errp)
-{
-    BlockBackend *blk;
-    BlockJob *job;
-    int ret;
-
-    if (bs->job) {
-        error_setg(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
-        return NULL;
-    }
-
-    if (job_id == NULL && !(flags & BLOCK_JOB_INTERNAL)) {
-        job_id = bdrv_get_device_name(bs);
-        if (!*job_id) {
-            error_setg(errp, "An explicit job ID is required for this node");
-            return NULL;
-        }
-    }
-
-    if (job_id) {
-        if (flags & BLOCK_JOB_INTERNAL) {
-            error_setg(errp, "Cannot specify job ID for internal block job");
-            return NULL;
-        }
-
-        if (!id_wellformed(job_id)) {
-            error_setg(errp, "Invalid job ID '%s'", job_id);
-            return NULL;
-        }
-
-        if (block_job_get(job_id)) {
-            error_setg(errp, "Job ID '%s' already in use", job_id);
-            return NULL;
-        }
-    }
-
-    blk = blk_new(perm, shared_perm);
-    ret = blk_insert_bs(blk, bs, errp);
-    if (ret < 0) {
-        blk_unref(blk);
-        return NULL;
-    }
-
-    job = g_malloc0(driver->instance_size);
-    job->driver        = driver;
-    job->id            = g_strdup(job_id);
-    job->blk           = blk;
-    job->cb            = cb;
-    job->opaque        = opaque;
-    job->busy          = false;
-    job->paused        = true;
-    job->pause_count   = 1;
-    job->refcnt        = 1;
-
-    error_setg(&job->blocker, "block device is in use by block job: %s",
-               BlockJobType_lookup[driver->job_type]);
-    block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort);
-    bs->job = job;
-
-    blk_set_dev_ops(blk, &block_job_dev_ops, job);
-    bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
-
-    QLIST_INSERT_HEAD(&block_jobs, job, job_list);
-
-    blk_add_aio_context_notifier(blk, block_job_attached_aio_context,
-                                 block_job_detach_aio_context, job);
-
-    /* Only set speed when necessary to avoid NotSupported error */
-    if (speed != 0) {
-        Error *local_err = NULL;
-
-        block_job_set_speed(job, speed, &local_err);
-        if (local_err) {
-            block_job_unref(job);
-            error_propagate(errp, local_err);
-            return NULL;
-        }
-    }
-    return job;
-}
-
 bool block_job_is_internal(BlockJob *job)
 {
     return (job->id == NULL);
@@ -XXX,XX +XXX,XX @@ void block_job_start(BlockJob *job)
     bdrv_coroutine_enter(blk_bs(job->blk), job->co);
 }
 
-void block_job_early_fail(BlockJob *job)
-{
-    block_job_unref(job);
-}
-
 static void block_job_completed_single(BlockJob *job)
 {
     if (!job->ret) {
@@ -XXX,XX +XXX,XX @@ static void block_job_completed_txn_success(BlockJob *job)
     }
 }
 
-void block_job_completed(BlockJob *job, int ret)
-{
-    assert(blk_bs(job->blk)->job == job);
-    assert(!job->completed);
-    job->completed = true;
-    job->ret = ret;
-    if (!job->txn) {
-        block_job_completed_single(job);
-    } else if (ret < 0 || block_job_is_cancelled(job)) {
-        block_job_completed_txn_abort(job);
-    } else {
-        block_job_completed_txn_success(job);
-    }
-}
-
 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
 {
     Error *local_err = NULL;
@@ -XXX,XX +XXX,XX @@ void block_job_user_pause(BlockJob *job)
     block_job_pause(job);
 }
 
-static bool block_job_should_pause(BlockJob *job)
-{
-    return job->pause_count > 0;
-}
-
 bool block_job_user_paused(BlockJob *job)
 {
     return job->user_paused;
 }
 
-void coroutine_fn block_job_pause_point(BlockJob *job)
-{
-    assert(job && block_job_started(job));
-
-    if (!block_job_should_pause(job)) {
-        return;
-    }
-    if (block_job_is_cancelled(job)) {
-        return;
-    }
-
-    if (job->driver->pause) {
-        job->driver->pause(job);
-    }
-
-    if (block_job_should_pause(job) && !block_job_is_cancelled(job)) {
-        job->paused = true;
-        job->busy = false;
-        qemu_coroutine_yield(); /* wait for block_job_resume() */
-        job->busy = true;
-        job->paused = false;
-    }
-
-    if (job->driver->resume) {
-        job->driver->resume(job);
-    }
-}
-
 void block_job_user_resume(BlockJob *job)
 {
     if (job && job->user_paused && job->pause_count > 0) {
@@ -XXX,XX +XXX,XX @@ void block_job_user_resume(BlockJob *job)
     }
 }
 
-void block_job_enter(BlockJob *job)
-{
-    if (job->co && !job->busy) {
-        bdrv_coroutine_enter(blk_bs(job->blk), job->co);
-    }
-}
-
 void block_job_cancel(BlockJob *job)
 {
     if (block_job_started(job)) {
@@ -XXX,XX +XXX,XX @@ void block_job_cancel(BlockJob *job)
     }
 }
 
-bool block_job_is_cancelled(BlockJob *job)
-{
-    return job->cancelled;
-}
-
 void block_job_iostatus_reset(BlockJob *job)
 {
     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
@@ -XXX,XX +XXX,XX @@ int block_job_complete_sync(BlockJob *job, Error **errp)
     return block_job_finish_sync(job, &block_job_complete, errp);
 }
 
-void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns)
-{
-    assert(job->busy);
-
-    /* Check cancellation *before* setting busy = false, too!  */
-    if (block_job_is_cancelled(job)) {
-        return;
-    }
-
-    job->busy = false;
-    if (!block_job_should_pause(job)) {
-        co_aio_sleep_ns(blk_get_aio_context(job->blk), type, ns);
-    }
-    job->busy = true;
-
-    block_job_pause_point(job);
-}
-
-void block_job_yield(BlockJob *job)
-{
-    assert(job->busy);
-
-    /* Check cancellation *before* setting busy = false, too!  */
-    if (block_job_is_cancelled(job)) {
-        return;
-    }
-
-    job->busy = false;
-    if (!block_job_should_pause(job)) {
-        qemu_coroutine_yield();
-    }
-    job->busy = true;
-
-    block_job_pause_point(job);
-}
-
 BlockJobInfo *block_job_query(BlockJob *job, Error **errp)
 {
     BlockJobInfo *info;
@@ -XXX,XX +XXX,XX @@ static void block_job_event_completed(BlockJob *job, const char *msg)
                                         &error_abort);
 }
 
+/*
+ * API for block job drivers and the block layer.  These functions are
+ * declared in blockjob_int.h.
+ */
+
+void *block_job_create(const char *job_id, const BlockJobDriver *driver,
+                       BlockDriverState *bs, uint64_t perm,
+                       uint64_t shared_perm, int64_t speed, int flags,
+                       BlockCompletionFunc *cb, void *opaque, Error **errp)
+{
+    BlockBackend *blk;
+    BlockJob *job;
+    int ret;
+
+    if (bs->job) {
+        error_setg(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
+        return NULL;
+    }
+
+    if (job_id == NULL && !(flags & BLOCK_JOB_INTERNAL)) {
+        job_id = bdrv_get_device_name(bs);
+        if (!*job_id) {
+            error_setg(errp, "An explicit job ID is required for this node");
+            return NULL;
+        }
+    }
+
+    if (job_id) {
+        if (flags & BLOCK_JOB_INTERNAL) {
+            error_setg(errp, "Cannot specify job ID for internal block job");
+            return NULL;
+        }
+
+        if (!id_wellformed(job_id)) {
+            error_setg(errp, "Invalid job ID '%s'", job_id);
+            return NULL;
+        }
+
+        if (block_job_get(job_id)) {
+            error_setg(errp, "Job ID '%s' already in use", job_id);
+            return NULL;
+        }
+    }
+
+    blk = blk_new(perm, shared_perm);
+    ret = blk_insert_bs(blk, bs, errp);
+    if (ret < 0) {
+        blk_unref(blk);
+        return NULL;
+    }
+
+    job = g_malloc0(driver->instance_size);
+    job->driver        = driver;
+    job->id            = g_strdup(job_id);
+    job->blk           = blk;
+    job->cb            = cb;
+    job->opaque        = opaque;
+    job->busy          = false;
+    job->paused        = true;
+    job->pause_count   = 1;
+    job->refcnt        = 1;
+
+    error_setg(&job->blocker, "block device is in use by block job: %s",
+               BlockJobType_lookup[driver->job_type]);
+    block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort);
+    bs->job = job;
+
+    blk_set_dev_ops(blk, &block_job_dev_ops, job);
+    bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker);
+
+    QLIST_INSERT_HEAD(&block_jobs, job, job_list);
+
+    blk_add_aio_context_notifier(blk, block_job_attached_aio_context,
+                                 block_job_detach_aio_context, job);
+
+    /* Only set speed when necessary to avoid NotSupported error */
+    if (speed != 0) {
+        Error *local_err = NULL;
+
+        block_job_set_speed(job, speed, &local_err);
+        if (local_err) {
+            block_job_unref(job);
+            error_propagate(errp, local_err);
+            return NULL;
+        }
+    }
+    return job;
+}
+
 void block_job_pause_all(void)
 {
     BlockJob *job = NULL;
@@ -XXX,XX +XXX,XX @@ void block_job_pause_all(void)
     }
 }
 
+void block_job_early_fail(BlockJob *job)
+{
+    block_job_unref(job);
+}
+
+void block_job_completed(BlockJob *job, int ret)
+{
+    assert(blk_bs(job->blk)->job == job);
+    assert(!job->completed);
+    job->completed = true;
+    job->ret = ret;
+    if (!job->txn) {
+        block_job_completed_single(job);
+    } else if (ret < 0 || block_job_is_cancelled(job)) {
+        block_job_completed_txn_abort(job);
+    } else {
+        block_job_completed_txn_success(job);
+    }
+}
+
+static bool block_job_should_pause(BlockJob *job)
+{
+    return job->pause_count > 0;
+}
+
+void coroutine_fn block_job_pause_point(BlockJob *job)
+{
+    assert(job && block_job_started(job));
+
+    if (!block_job_should_pause(job)) {
+        return;
+    }
+    if (block_job_is_cancelled(job)) {
+        return;
+    }
+
+    if (job->driver->pause) {
+        job->driver->pause(job);
+    }
+
+    if (block_job_should_pause(job) && !block_job_is_cancelled(job)) {
+        job->paused = true;
+        job->busy = false;
+        qemu_coroutine_yield(); /* wait for block_job_resume() */
+        job->busy = true;
+        job->paused = false;
+    }
+
+    if (job->driver->resume) {
+        job->driver->resume(job);
+    }
+}
+
 void block_job_resume_all(void)
 {
     BlockJob *job = NULL;
@@ -XXX,XX +XXX,XX @@ void block_job_resume_all(void)
     }
 }
 
+void block_job_enter(BlockJob *job)
+{
+    if (job->co && !job->busy) {
+        bdrv_coroutine_enter(blk_bs(job->blk), job->co);
+    }
+}
+
+bool block_job_is_cancelled(BlockJob *job)
+{
+    return job->cancelled;
+}
+
+void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns)
+{
+    assert(job->busy);
+
+    /* Check cancellation *before* setting busy = false, too!  */
+    if (block_job_is_cancelled(job)) {
+        return;
+    }
+
+    job->busy = false;
+    if (!block_job_should_pause(job)) {
+        co_aio_sleep_ns(blk_get_aio_context(job->blk), type, ns);
+    }
+    job->busy = true;
+
+    block_job_pause_point(job);
+}
+
+void block_job_yield(BlockJob *job)
+{
+    assert(job->busy);
+
+    /* Check cancellation *before* setting busy = false, too!  */
+    if (block_job_is_cancelled(job)) {
+        return;
+    }
+
+    job->busy = false;
+    if (!block_job_should_pause(job)) {
+        qemu_coroutine_yield();
+    }
+    job->busy = true;
+
+    block_job_pause_point(job);
+}
+
 void block_job_event_ready(BlockJob *job)
 {
     job->ready = true;
-- 
2.9.3

From: Paolo Bonzini <pbonzini@redhat.com>

Outside blockjob.c, the block_job_iostatus_reset function is used once
in the monitor and once in BlockBackend.  When we introduce the block
job mutex, block_job_iostatus_reset's client is going to be the block
layer (for which blockjob.c will take the block job mutex) rather than
the monitor (which will take the block job mutex by itself).

The monitor's call to block_job_iostatus_reset from the monitor comes
just before the sole call to block_job_user_resume, so reset the
iostatus directly from block_job_iostatus_reset.  This will avoid
the need to introduce separate block_job_iostatus_reset and
block_job_iostatus_reset_locked APIs.

After making this change, move the function together with the others
that were moved in the previous patch.

diff --git a/blockdev.c b/blockdev.c
index XXXXXXX..XXXXXXX 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -XXX,XX +XXX,XX @@ void qmp_block_job_resume(const char *device, Error **errp)
     }
 
     trace_qmp_block_job_resume(job);
-    block_job_iostatus_reset(job);
     block_job_user_resume(job);
     aio_context_release(aio_context);
 }
diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ void block_job_user_resume(BlockJob *job)
 {
     if (job && job->user_paused && job->pause_count > 0) {
         job->user_paused = false;
+        block_job_iostatus_reset(job);
         block_job_resume(job);
     }
 }
@@ -XXX,XX +XXX,XX @@ void block_job_cancel(BlockJob *job)
     }
 }
 
-void block_job_iostatus_reset(BlockJob *job)
-{
-    job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
-}
-
 static int block_job_finish_sync(BlockJob *job,
                                  void (*finish)(BlockJob *, Error **errp),
                                  Error **errp)
@@ -XXX,XX +XXX,XX @@ void block_job_yield(BlockJob *job)
     block_job_pause_point(job);
 }
 
+void block_job_iostatus_reset(BlockJob *job)
+{
+    job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
+}
+
 void block_job_event_ready(BlockJob *job)
 {
     job->ready = true;
-- 
2.9.3

From: Paolo Bonzini <pbonzini@redhat.com>

The new functions helps respecting the invariant that the coroutine
is entered with false user_resume, zero pause count and no error
recorded in the iostatus.

Resetting the iostatus is now common to all of block_job_cancel_async,
block_job_user_resume and block_job_iostatus_reset, albeit with slight
differences:

- block_job_cancel_async resets the iostatus, and resumes the job if
there was an error, but the coroutine is not restarted immediately.
For example the caller may continue with a call to block_job_finish_sync.

- block_job_user_resume resets the iostatus.  It wants to resume the job
unconditionally, even if there was no error.

- block_job_iostatus_reset doesn't resume the job at all.  Maybe that's
a bug but it should be fixed separately.

block_job_iostatus_reset does the least common denominator, so add some
checking but otherwise leave it as the entry point for resetting the
iostatus.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170508141310.8674-8-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 blockjob.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ static void block_job_completed_single(BlockJob *job)
     block_job_unref(job);
 }
 
+static void block_job_cancel_async(BlockJob *job)
+{
+    if (job->iostatus != BLOCK_DEVICE_IO_STATUS_OK) {
+        block_job_iostatus_reset(job);
+    }
+    if (job->user_paused) {
+        /* Do not call block_job_enter here, the caller will handle it.  */
+        job->user_paused = false;
+        job->pause_count--;
+    }
+    job->cancelled = true;
+}
+
 static void block_job_completed_txn_abort(BlockJob *job)
 {
     AioContext *ctx;
@@ -XXX,XX +XXX,XX @@ static void block_job_completed_txn_abort(BlockJob *job)
              * them; this job, however, may or may not be cancelled, depending
              * on the caller, so leave it. */
             if (other_job != job) {
-                other_job->cancelled = true;
+                block_job_cancel_async(other_job);
             }
             continue;
         }
@@ -XXX,XX +XXX,XX @@ bool block_job_user_paused(BlockJob *job)
 void block_job_user_resume(BlockJob *job)
 {
     if (job && job->user_paused && job->pause_count > 0) {
-        job->user_paused = false;
         block_job_iostatus_reset(job);
+        job->user_paused = false;
         block_job_resume(job);
     }
 }
@@ -XXX,XX +XXX,XX @@ void block_job_user_resume(BlockJob *job)
 void block_job_cancel(BlockJob *job)
 {
     if (block_job_started(job)) {
-        job->cancelled = true;
-        block_job_iostatus_reset(job);
+        block_job_cancel_async(job);
         block_job_enter(job);
     } else {
         block_job_completed(job, -ECANCELED);
@@ -XXX,XX +XXX,XX @@ void block_job_yield(BlockJob *job)
 
 void block_job_iostatus_reset(BlockJob *job)
 {
+    if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
+        return;
+    }
+    assert(job->user_paused && job->pause_count > 0);
     job->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
 }
 
-- 
2.9.3

From: Paolo Bonzini <pbonzini@redhat.com>

Yet another pure code movement patch, preparing for the next change.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170508141310.8674-9-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 blockjob.c | 128 ++++++++++++++++++++++++++++++-------------------------------
 1 file changed, 64 insertions(+), 64 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ BlockJob *block_job_get(const char *id)
     return NULL;
 }
 
+BlockJobTxn *block_job_txn_new(void)
+{
+    BlockJobTxn *txn = g_new0(BlockJobTxn, 1);
+    QLIST_INIT(&txn->jobs);
+    txn->refcnt = 1;
+    return txn;
+}
+
+static void block_job_txn_ref(BlockJobTxn *txn)
+{
+    txn->refcnt++;
+}
+
+void block_job_txn_unref(BlockJobTxn *txn)
+{
+    if (txn && --txn->refcnt == 0) {
+        g_free(txn);
+    }
+}
+
+void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job)
+{
+    if (!txn) {
+        return;
+    }
+
+    assert(!job->txn);
+    job->txn = txn;
+
+    QLIST_INSERT_HEAD(&txn->jobs, job, txn_list);
+    block_job_txn_ref(txn);
+}
+
 static void block_job_pause(BlockJob *job)
 {
     job->pause_count++;
@@ -XXX,XX +XXX,XX @@ static void block_job_cancel_async(BlockJob *job)
     job->cancelled = true;
 }
 
+static int block_job_finish_sync(BlockJob *job,
+                                 void (*finish)(BlockJob *, Error **errp),
+                                 Error **errp)
+{
+    Error *local_err = NULL;
+    int ret;
+
+    assert(blk_bs(job->blk)->job == job);
+
+    block_job_ref(job);
+
+    finish(job, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        block_job_unref(job);
+        return -EBUSY;
+    }
+    /* block_job_drain calls block_job_enter, and it should be enough to
+     * induce progress until the job completes or moves to the main thread.
+    */
+    while (!job->deferred_to_main_loop && !job->completed) {
+        block_job_drain(job);
+    }
+    while (!job->completed) {
+        aio_poll(qemu_get_aio_context(), true);
+    }
+    ret = (job->cancelled && job->ret == 0) ? -ECANCELED : job->ret;
+    block_job_unref(job);
+    return ret;
+}
+
 static void block_job_completed_txn_abort(BlockJob *job)
 {
     AioContext *ctx;
@@ -XXX,XX +XXX,XX @@ void block_job_cancel(BlockJob *job)
     }
 }
 
-static int block_job_finish_sync(BlockJob *job,
-                                 void (*finish)(BlockJob *, Error **errp),
-                                 Error **errp)
-{
-    Error *local_err = NULL;
-    int ret;
-
-    assert(blk_bs(job->blk)->job == job);
-
-    block_job_ref(job);
-
-    finish(job, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        block_job_unref(job);
-        return -EBUSY;
-    }
-    /* block_job_drain calls block_job_enter, and it should be enough to
-     * induce progress until the job completes or moves to the main thread.
-    */
-    while (!job->deferred_to_main_loop && !job->completed) {
-        block_job_drain(job);
-    }
-    while (!job->completed) {
-        aio_poll(qemu_get_aio_context(), true);
-    }
-    ret = (job->cancelled && job->ret == 0) ? -ECANCELED : job->ret;
-    block_job_unref(job);
-    return ret;
-}
-
 /* A wrapper around block_job_cancel() taking an Error ** parameter so it may be
  * used with block_job_finish_sync() without the need for (rather nasty)
  * function pointer casts there. */
@@ -XXX,XX +XXX,XX @@ void block_job_defer_to_main_loop(BlockJob *job,
     aio_bh_schedule_oneshot(qemu_get_aio_context(),
                             block_job_defer_to_main_loop_bh, data);
 }
-
-BlockJobTxn *block_job_txn_new(void)
-{
-    BlockJobTxn *txn = g_new0(BlockJobTxn, 1);
-    QLIST_INIT(&txn->jobs);
-    txn->refcnt = 1;
-    return txn;
-}
-
-static void block_job_txn_ref(BlockJobTxn *txn)
-{
-    txn->refcnt++;
-}
-
-void block_job_txn_unref(BlockJobTxn *txn)
-{
-    if (txn && --txn->refcnt == 0) {
-        g_free(txn);
-    }
-}
-
-void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job)
-{
-    if (!txn) {
-        return;
-    }
-
-    assert(!job->txn);
-    job->txn = txn;
-
-    QLIST_INSERT_HEAD(&txn->jobs, job, txn_list);
-    block_job_txn_ref(txn);
-}
-- 
2.9.3

From: Paolo Bonzini <pbonzini@redhat.com>

Unlike test-blockjob-txn, QMP releases the reference to the transaction
before the jobs finish.  Thus, qemu-iotest 124 showed a failure while
working on the next patch that the unit tests did not have.  Make
the test a little nastier.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170508141310.8674-10-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 tests/test-blockjob-txn.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tests/test-blockjob-txn.c b/tests/test-blockjob-txn.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/test-blockjob-txn.c
+++ b/tests/test-blockjob-txn.c
@@ -XXX,XX +XXX,XX @@ static void test_pair_jobs(int expected1, int expected2)
     block_job_start(job1);
     block_job_start(job2);
 
+    /* Release our reference now to trigger as many nice
+     * use-after-free bugs as possible.
+     */
+    block_job_txn_unref(txn);
+
     if (expected1 == -ECANCELED) {
         block_job_cancel(job1);
     }
@@ -XXX,XX +XXX,XX @@ static void test_pair_jobs(int expected1, int expected2)
 
     g_assert_cmpint(result1, ==, expected1);
     g_assert_cmpint(result2, ==, expected2);
-
-    block_job_txn_unref(txn);
 }
 
 static void test_pair_jobs_success(void)
-- 
2.9.3

From: Paolo Bonzini <pbonzini@redhat.com>

This splits the part that touches job states from the part that invokes
callbacks.  It will make the code simpler to understand once job states will
be protected by a different mutex than the AioContext lock.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170508141310.8674-11-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 blockjob.c | 35 ++++++++++++++++++++++-------------
 1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ void block_job_start(BlockJob *job)
 
 static void block_job_completed_single(BlockJob *job)
 {
+    assert(job->completed);
+
     if (!job->ret) {
         if (job->driver->commit) {
             job->driver->commit(job);
@@ -XXX,XX +XXX,XX @@ static int block_job_finish_sync(BlockJob *job,
 
     block_job_ref(job);
 
-    finish(job, &local_err);
+    if (finish) {
+        finish(job, &local_err);
+    }
     if (local_err) {
         error_propagate(errp, local_err);
         block_job_unref(job);
@@ -XXX,XX +XXX,XX @@ static void block_job_completed_txn_abort(BlockJob *job)
 {
     AioContext *ctx;
     BlockJobTxn *txn = job->txn;
-    BlockJob *other_job, *next;
+    BlockJob *other_job;
 
     if (txn->aborting) {
         /*
@@ -XXX,XX +XXX,XX @@ static void block_job_completed_txn_abort(BlockJob *job)
         return;
     }
     txn->aborting = true;
+    block_job_txn_ref(txn);
+
     /* We are the first failed job. Cancel other jobs. */
     QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
         ctx = blk_get_aio_context(other_job->blk);
         aio_context_acquire(ctx);
     }
+
+    /* Other jobs are effectively cancelled by us, set the status for
+     * them; this job, however, may or may not be cancelled, depending
+     * on the caller, so leave it. */
     QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
-        if (other_job == job || other_job->completed) {
-            /* Other jobs are "effectively" cancelled by us, set the status for
-             * them; this job, however, may or may not be cancelled, depending
-             * on the caller, so leave it. */
-            if (other_job != job) {
-                block_job_cancel_async(other_job);
-            }
-            continue;
+        if (other_job != job) {
+            block_job_cancel_async(other_job);
         }
-        block_job_cancel_sync(other_job);
-        assert(other_job->completed);
     }
-    QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) {
+    while (!QLIST_EMPTY(&txn->jobs)) {
+        other_job = QLIST_FIRST(&txn->jobs);
         ctx = blk_get_aio_context(other_job->blk);
+        if (!other_job->completed) {
+            assert(other_job->cancelled);
+            block_job_finish_sync(other_job, NULL, NULL);
+        }
         block_job_completed_single(other_job);
         aio_context_release(ctx);
     }
+
+    block_job_txn_unref(txn);
 }
 
 static void block_job_completed_txn_success(BlockJob *job)
-- 
2.9.3

From: Paolo Bonzini <pbonzini@redhat.com>

All block jobs are using block_job_defer_to_main_loop as the final
step just before the coroutine terminates.  At this point,
block_job_enter should do nothing, but currently it restarts
the freed coroutine.

Now, the job->co states should probably be changed to an enum
(e.g. BEFORE_START, STARTED, YIELDED, COMPLETED) subsuming
block_job_started, job->deferred_to_main_loop and job->busy.
For now, this patch eliminates the problematic reenter by
removing the reset of job->deferred_to_main_loop (which served
no purpose, as far as I could see) and checking the flag in
block_job_enter.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170508141310.8674-12-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 blockjob.c                   | 10 ++++++++--
 include/block/blockjob_int.h |  3 ++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index XXXXXXX..XXXXXXX 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -XXX,XX +XXX,XX @@ void block_job_resume_all(void)
 
 void block_job_enter(BlockJob *job)
 {
-    if (job->co && !job->busy) {
+    if (!block_job_started(job)) {
+        return;
+    }
+    if (job->deferred_to_main_loop) {
+        return;
+    }
+
+    if (!job->busy) {
         bdrv_coroutine_enter(blk_bs(job->blk), job->co);
     }
 }
@@ -XXX,XX +XXX,XX @@ static void block_job_defer_to_main_loop_bh(void *opaque)
         aio_context_acquire(aio_context);
     }
 
-    data->job->deferred_to_main_loop = false;
     data->fn(data->job, data->opaque);
 
     if (aio_context != data->aio_context) {
diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/blockjob_int.h
+++ b/include/block/blockjob_int.h
@@ -XXX,XX +XXX,XX @@ typedef void BlockJobDeferToMainLoopFn(BlockJob *job, void *opaque);
  * @fn: The function to run in the main loop
  * @opaque: The opaque value that is passed to @fn
  *
- * Execute a given function in the main loop with the BlockDriverState
+ * This function must be called by the main job coroutine just before it
+ * returns.  @fn is executed in the main loop with the BlockDriverState
  * AioContext acquired.  Block jobs must call bdrv_unref(), bdrv_close(), and
  * anything that uses bdrv_drain_all() in the main loop.
  *
-- 
2.9.3

On current released versions of glusterfs, glfs_lseek() will sometimes
return invalid values for SEEK_DATA or SEEK_HOLE.  For SEEK_DATA and
SEEK_HOLE, the returned value should be >= the passed offset, or < 0 in
the case of error:

LSEEK(2):

off_t lseek(int fd, off_t offset, int whence);

[...]

SEEK_HOLE
              Adjust  the file offset to the next hole in the file greater
              than or equal to offset.  If offset points into the middle of
              a hole, then the file offset is set to offset.  If there is no
              hole past offset, then the file offset is adjusted to the end
              of the file (i.e., there is  an implicit hole at the end of
              any file).

[...]

RETURN VALUE
              Upon  successful  completion,  lseek()  returns  the resulting
              offset location as measured in bytes from the beginning of the
              file.  On error, the value (off_t) -1 is returned and errno is
              set to indicate the error

However, occasionally glfs_lseek() for SEEK_HOLE/DATA will return a
value less than the passed offset, yet greater than zero.

For instance, here are example values observed from this call:

offs = glfs_lseek(s->fd, start, SEEK_HOLE);
    if (offs < 0) {
        return -errno;          /* D1 and (H3 or H4) */
    }

start == 7608336384
offs == 7607877632

This causes QEMU to abort on the assert test.  When this value is
returned, errno is also 0.

This is a reported and known bug to glusterfs:
https://bugzilla.redhat.com/show_bug.cgi?id=1425293

Although this is being fixed in gluster, we still should work around it
in QEMU, given that multiple released versions of gluster behave this
way.

This patch treats the return case of (offs < start) the same as if an
error value other than ENXIO is returned; we will assume we learned
nothing, and there are no holes in the file.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Message-id: 87c0140e9407c08f6e74b04131b610f2e27c014c.1495560397.git.jcody@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 block/gluster.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/block/gluster.c b/block/gluster.c
index XXXXXXX..XXXXXXX 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -XXX,XX +XXX,XX @@ static int find_allocation(BlockDriverState *bs, off_t start,
     if (offs < 0) {
         return -errno;          /* D3 or D4 */
     }
-    assert(offs >= start);
+
+    if (offs < start) {
+        /* This is not a valid return by lseek().  We are safe to just return
+         * -EIO in this case, and we'll treat it like D4. Unfortunately some
+         *  versions of gluster server will return offs < start, so an assert
+         *  here will unnecessarily abort QEMU. */
+        return -EIO;
+    }
 
     if (offs > start) {
         /* D2: in hole, next data at offs */
@@ -XXX,XX +XXX,XX @@ static int find_allocation(BlockDriverState *bs, off_t start,
     if (offs < 0) {
         return -errno;          /* D1 and (H3 or H4) */
     }
-    assert(offs >= start);
+
+    if (offs < start) {
+        /* This is not a valid return by lseek().  We are safe to just return
+         * -EIO in this case, and we'll treat it like H4. Unfortunately some
+         *  versions of gluster server will return offs < start, so an assert
+         *  here will unnecessarily abort QEMU. */
+        return -EIO;
+    }
 
     if (offs > start) {
         /*
-- 
2.9.3

The following changes since commit ac793156f650ae2d77834932d72224175ee69086:

Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20201020-1' into staging (2020-10-20 21:11:35 +0100)

are available in the Git repository at:

https://gitlab.com/stefanha/qemu.git tags/block-pull-request

for you to fetch changes up to 32a3fd65e7e3551337fd26bfc0e2f899d70c028c:

iotests: add commit top->base cases to 274 (2020-10-22 09:55:39 +0100)

----------------------------------------------------------------
Pull request

v2:
 * Fix format string issues on 32-bit hosts [Peter]
 * Fix qemu-nbd.c CONFIG_POSIX ifdef issue [Eric]
 * Fix missing eventfd.h header on macOS [Peter]
 * Drop unreliable vhost-user-blk test (will send a new patch when ready) [Peter]

This pull request contains the vhost-user-blk server by Coiby Xu along with my
additions, block/nvme.c alignment and hardware error statistics by Philippe
Mathieu-Daudé, and bdrv_co_block_status_above() fixes by Vladimir
Sementsov-Ogievskiy.

----------------------------------------------------------------

Coiby Xu (6):
  libvhost-user: Allow vu_message_read to be replaced
  libvhost-user: remove watch for kick_fd when de-initialize vu-dev
  util/vhost-user-server: generic vhost user server
  block: move logical block size check function to a common utility
    function
  block/export: vhost-user block device backend server
  MAINTAINERS: Add vhost-user block device backend server maintainer

Philippe Mathieu-Daudé (1):
  block/nvme: Add driver statistics for access alignment and hw errors

Stefan Hajnoczi (16):
  util/vhost-user-server: s/fileds/fields/ typo fix
  util/vhost-user-server: drop unnecessary QOM cast
  util/vhost-user-server: drop unnecessary watch deletion
  block/export: consolidate request structs into VuBlockReq
  util/vhost-user-server: drop unused DevicePanicNotifier
  util/vhost-user-server: fix memory leak in vu_message_read()
  util/vhost-user-server: check EOF when reading payload
  util/vhost-user-server: rework vu_client_trip() coroutine lifecycle
  block/export: report flush errors
  block/export: convert vhost-user-blk server to block export API
  util/vhost-user-server: move header to include/
  util/vhost-user-server: use static library in meson.build
  qemu-storage-daemon: avoid compiling blockdev_ss twice
  block: move block exports to libblockdev
  block/export: add iothread and fixed-iothread options
  block/export: add vhost-user-blk multi-queue support

Vladimir Sementsov-Ogievskiy (5):
  block/io: fix bdrv_co_block_status_above
  block/io: bdrv_common_block_status_above: support include_base
  block/io: bdrv_common_block_status_above: support bs == base
  block/io: fix bdrv_is_allocated_above
  iotests: add commit top->base cases to 274

-- 
2.26.2

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Keep statistics of some hardware errors, and number of
aligned/unaligned I/O accesses.

QMP example booting a full RHEL 8.3 aarch64 guest:

{ "execute": "query-blockstats" }
{
    "return": [
        {
            "device": "",
            "node-name": "drive0",
            "stats": {
                "flush_total_time_ns": 6026948,
                "wr_highest_offset": 3383991230464,
                "wr_total_time_ns": 807450995,
                "failed_wr_operations": 0,
                "failed_rd_operations": 0,
                "wr_merged": 3,
                "wr_bytes": 50133504,
                "failed_unmap_operations": 0,
                "failed_flush_operations": 0,
                "account_invalid": false,
                "rd_total_time_ns": 1846979900,
                "flush_operations": 130,
                "wr_operations": 659,
                "rd_merged": 1192,
                "rd_bytes": 218244096,
                "account_failed": false,
                "idle_time_ns": 2678641497,
                "rd_operations": 7406,
            },
            "driver-specific": {
                "driver": "nvme",
                "completion-errors": 0,
                "unaligned-accesses": 2959,
                "aligned-accesses": 4477
            },
            "qdev": "/machine/peripheral-anon/device[0]/virtio-backend"
        }
    ]
}

Suggested-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20201001162939.1567915-1-philmd@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qapi/block-core.json | 24 +++++++++++++++++++++++-
 block/nvme.c         | 27 +++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index XXXXXXX..XXXXXXX 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -XXX,XX +XXX,XX @@
       'discard-nb-failed': 'uint64',
       'discard-bytes-ok': 'uint64' } }
 
+##
+# @BlockStatsSpecificNvme:
+#
+# NVMe driver statistics
+#
+# @completion-errors: The number of completion errors.
+#
+# @aligned-accesses: The number of aligned accesses performed by
+#                    the driver.
+#
+# @unaligned-accesses: The number of unaligned accesses performed by
+#                      the driver.
+#
+# Since: 5.2
+##
+{ 'struct': 'BlockStatsSpecificNvme',
+  'data': {
+      'completion-errors': 'uint64',
+      'aligned-accesses': 'uint64',
+      'unaligned-accesses': 'uint64' } }
+
 ##
 # @BlockStatsSpecific:
 #
@@ -XXX,XX +XXX,XX @@
   'discriminator': 'driver',
   'data': {
       'file': 'BlockStatsSpecificFile',
-      'host_device': 'BlockStatsSpecificFile' } }
+      'host_device': 'BlockStatsSpecificFile',
+      'nvme': 'BlockStatsSpecificNvme' } }
 
 ##
 # @BlockStats:
diff --git a/block/nvme.c b/block/nvme.c
index XXXXXXX..XXXXXXX 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -XXX,XX +XXX,XX @@ struct BDRVNVMeState {
 
     /* PCI address (required for nvme_refresh_filename()) */
     char *device;
+
+    struct {
+        uint64_t completion_errors;
+        uint64_t aligned_accesses;
+        uint64_t unaligned_accesses;
+    } stats;
 };
 
 #define NVME_BLOCK_OPT_DEVICE "device"
@@ -XXX,XX +XXX,XX @@ static bool nvme_process_completion(NVMeQueuePair *q)
             break;
         }
         ret = nvme_translate_error(c);
+        if (ret) {
+            s->stats.completion_errors++;
+        }
         q->cq.head = (q->cq.head + 1) % NVME_QUEUE_SIZE;
         if (!q->cq.head) {
             q->cq_phase = !q->cq_phase;
@@ -XXX,XX +XXX,XX @@ static int nvme_co_prw(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
     assert(QEMU_IS_ALIGNED(bytes, s->page_size));
     assert(bytes <= s->max_transfer);
     if (nvme_qiov_aligned(bs, qiov)) {
+        s->stats.aligned_accesses++;
         return nvme_co_prw_aligned(bs, offset, bytes, qiov, is_write, flags);
     }
+    s->stats.unaligned_accesses++;
     trace_nvme_prw_buffered(s, offset, bytes, qiov->niov, is_write);
     buf = qemu_try_memalign(s->page_size, bytes);
 
@@ -XXX,XX +XXX,XX @@ static void nvme_unregister_buf(BlockDriverState *bs, void *host)
     qemu_vfio_dma_unmap(s->vfio, host);
 }
 
+static BlockStatsSpecific *nvme_get_specific_stats(BlockDriverState *bs)
+{
+    BlockStatsSpecific *stats = g_new(BlockStatsSpecific, 1);
+    BDRVNVMeState *s = bs->opaque;
+
+    stats->driver = BLOCKDEV_DRIVER_NVME;
+    stats->u.nvme = (BlockStatsSpecificNvme) {
+        .completion_errors = s->stats.completion_errors,
+        .aligned_accesses = s->stats.aligned_accesses,
+        .unaligned_accesses = s->stats.unaligned_accesses,
+    };
+
+    return stats;
+}
+
 static const char *const nvme_strong_runtime_opts[] = {
     NVME_BLOCK_OPT_DEVICE,
     NVME_BLOCK_OPT_NAMESPACE,
@@ -XXX,XX +XXX,XX @@ static BlockDriver bdrv_nvme = {
     .bdrv_refresh_filename    = nvme_refresh_filename,
     .bdrv_refresh_limits      = nvme_refresh_limits,
     .strong_runtime_opts      = nvme_strong_runtime_opts,
+    .bdrv_get_specific_stats  = nvme_get_specific_stats,
 
     .bdrv_detach_aio_context  = nvme_detach_aio_context,
     .bdrv_attach_aio_context  = nvme_attach_aio_context,
-- 
2.26.2

From: Coiby Xu <coiby.xu@gmail.com>

Allow vu_message_read to be replaced by one which will make use of the
QIOChannel functions. Thus reading vhost-user message won't stall the
guest. For slave channel, we still use the default vu_message_read.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200918080912.321299-2-coiby.xu@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 contrib/libvhost-user/libvhost-user.h      | 21 +++++++++++++++++++++
 contrib/libvhost-user/libvhost-user-glib.c |  2 +-
 contrib/libvhost-user/libvhost-user.c      | 14 +++++++-------
 tests/vhost-user-bridge.c                  |  2 ++
 tools/virtiofsd/fuse_virtio.c              |  4 ++--
 5 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h
index XXXXXXX..XXXXXXX 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -XXX,XX +XXX,XX @@
  */
 #define VHOST_USER_MAX_RAM_SLOTS 32
 
+#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
+
 typedef enum VhostSetConfigType {
     VHOST_SET_CONFIG_TYPE_MASTER = 0,
     VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
@@ -XXX,XX +XXX,XX @@ typedef uint64_t (*vu_get_features_cb) (VuDev *dev);
 typedef void (*vu_set_features_cb) (VuDev *dev, uint64_t features);
 typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg,
                                   int *do_reply);
+typedef bool (*vu_read_msg_cb) (VuDev *dev, int sock, VhostUserMsg *vmsg);
 typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool started);
 typedef bool (*vu_queue_is_processed_in_order_cb) (VuDev *dev, int qidx);
 typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, uint32_t len);
@@ -XXX,XX +XXX,XX @@ struct VuDev {
     bool broken;
     uint16_t max_queues;
 
+    /* @read_msg: custom method to read vhost-user message
+     *
+     * Read data from vhost_user socket fd and fill up
+     * the passed VhostUserMsg *vmsg struct.
+     *
+     * If reading fails, it should close the received set of file
+     * descriptors as socket message's auxiliary data.
+     *
+     * For the details, please refer to vu_message_read in libvhost-user.c
+     * which will be used by default if not custom method is provided when
+     * calling vu_init
+     *
+     * Returns: true if vhost-user message successfully received,
+     *          otherwise return false.
+     *
+     */
+    vu_read_msg_cb read_msg;
     /* @set_watch: add or update the given fd to the watch set,
      * call cb when condition is met */
     vu_set_watch_cb set_watch;
@@ -XXX,XX +XXX,XX @@ bool vu_init(VuDev *dev,
              uint16_t max_queues,
              int socket,
              vu_panic_cb panic,
+             vu_read_msg_cb read_msg,
              vu_set_watch_cb set_watch,
              vu_remove_watch_cb remove_watch,
              const VuDevIface *iface);
diff --git a/contrib/libvhost-user/libvhost-user-glib.c b/contrib/libvhost-user/libvhost-user-glib.c
index XXXXXXX..XXXXXXX 100644
--- a/contrib/libvhost-user/libvhost-user-glib.c
+++ b/contrib/libvhost-user/libvhost-user-glib.c
@@ -XXX,XX +XXX,XX @@ vug_init(VugDev *dev, uint16_t max_queues, int socket,
     g_assert(dev);
     g_assert(iface);
 
-    if (!vu_init(&dev->parent, max_queues, socket, panic, set_watch,
+    if (!vu_init(&dev->parent, max_queues, socket, panic, NULL, set_watch,
                  remove_watch, iface)) {
         return false;
     }
diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index XXXXXXX..XXXXXXX 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -XXX,XX +XXX,XX @@
 /* The version of inflight buffer */
 #define INFLIGHT_VERSION 1
 
-#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
-
 /* The version of the protocol we support */
 #define VHOST_USER_VERSION 1
 #define LIBVHOST_USER_DEBUG 0
@@ -XXX,XX +XXX,XX @@ have_userfault(void)
 }
 
 static bool
-vu_message_read(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
+vu_message_read_default(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
 {
     char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS * sizeof(int))] = {};
     struct iovec iov = {
@@ -XXX,XX +XXX,XX @@ vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg)
         goto out;
     }
 
-    if (!vu_message_read(dev, dev->slave_fd, &msg_reply)) {
+    if (!vu_message_read_default(dev, dev->slave_fd, &msg_reply)) {
         goto out;
     }
 
@@ -XXX,XX +XXX,XX @@ vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg)
     /* Wait for QEMU to confirm that it's registered the handler for the
      * faults.
      */
-    if (!vu_message_read(dev, dev->sock, vmsg) ||
+    if (!dev->read_msg(dev, dev->sock, vmsg) ||
         vmsg->size != sizeof(vmsg->payload.u64) ||
         vmsg->payload.u64 != 0) {
         vu_panic(dev, "failed to receive valid ack for postcopy set-mem-table");
@@ -XXX,XX +XXX,XX @@ vu_dispatch(VuDev *dev)
     int reply_requested;
     bool need_reply, success = false;
 
-    if (!vu_message_read(dev, dev->sock, &vmsg)) {
+    if (!dev->read_msg(dev, dev->sock, &vmsg)) {
         goto end;
     }
 
@@ -XXX,XX +XXX,XX @@ vu_init(VuDev *dev,
         uint16_t max_queues,
         int socket,
         vu_panic_cb panic,
+        vu_read_msg_cb read_msg,
         vu_set_watch_cb set_watch,
         vu_remove_watch_cb remove_watch,
         const VuDevIface *iface)
@@ -XXX,XX +XXX,XX @@ vu_init(VuDev *dev,
 
     dev->sock = socket;
     dev->panic = panic;
+    dev->read_msg = read_msg ? read_msg : vu_message_read_default;
     dev->set_watch = set_watch;
     dev->remove_watch = remove_watch;
     dev->iface = iface;
@@ -XXX,XX +XXX,XX @@ static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync)
 
         vu_message_write(dev, dev->slave_fd, &vmsg);
         if (ack) {
-            vu_message_read(dev, dev->slave_fd, &vmsg);
+            vu_message_read_default(dev, dev->slave_fd, &vmsg);
         }
         return;
     }
diff --git a/tests/vhost-user-bridge.c b/tests/vhost-user-bridge.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/vhost-user-bridge.c
+++ b/tests/vhost-user-bridge.c
@@ -XXX,XX +XXX,XX @@ vubr_accept_cb(int sock, void *ctx)
                  VHOST_USER_BRIDGE_MAX_QUEUES,
                  conn_fd,
                  vubr_panic,
+                 NULL,
                  vubr_set_watch,
                  vubr_remove_watch,
                  &vuiface)) {
@@ -XXX,XX +XXX,XX @@ vubr_new(const char *path, bool client)
                      VHOST_USER_BRIDGE_MAX_QUEUES,
                      dev->sock,
                      vubr_panic,
+                     NULL,
                      vubr_set_watch,
                      vubr_remove_watch,
                      &vuiface)) {
diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c
index XXXXXXX..XXXXXXX 100644
--- a/tools/virtiofsd/fuse_virtio.c
+++ b/tools/virtiofsd/fuse_virtio.c
@@ -XXX,XX +XXX,XX @@ int virtio_session_mount(struct fuse_session *se)
     se->vu_socketfd = data_sock;
     se->virtio_dev->se = se;
     pthread_rwlock_init(&se->virtio_dev->vu_dispatch_rwlock, NULL);
-    vu_init(&se->virtio_dev->dev, 2, se->vu_socketfd, fv_panic, fv_set_watch,
-            fv_remove_watch, &fv_iface);
+    vu_init(&se->virtio_dev->dev, 2, se->vu_socketfd, fv_panic, NULL,
+            fv_set_watch, fv_remove_watch, &fv_iface);
 
     return 0;
 }
-- 
2.26.2

From: Coiby Xu <coiby.xu@gmail.com>

Sharing QEMU devices via vhost-user protocol.

Only one vhost-user client can connect to the server one time.

diff --git a/util/vhost-user-server.h b/util/vhost-user-server.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/util/vhost-user-server.h
@@ -XXX,XX +XXX,XX @@
+/*
+ * Sharing QEMU devices via vhost-user protocol
+ *
+ * Copyright (c) Coiby Xu <coiby.xu@gmail.com>.
+ * Copyright (c) 2020 Red Hat, Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#ifndef VHOST_USER_SERVER_H
+#define VHOST_USER_SERVER_H
+
+#include "contrib/libvhost-user/libvhost-user.h"
+#include "io/channel-socket.h"
+#include "io/channel-file.h"
+#include "io/net-listener.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "standard-headers/linux/virtio_blk.h"
+
+typedef struct VuFdWatch {
+    VuDev *vu_dev;
+    int fd; /*kick fd*/
+    void *pvt;
+    vu_watch_cb cb;
+    bool processing;
+    QTAILQ_ENTRY(VuFdWatch) next;
+} VuFdWatch;
+
+typedef struct VuServer VuServer;
+typedef void DevicePanicNotifierFn(VuServer *server);
+
+struct VuServer {
+    QIONetListener *listener;
+    AioContext *ctx;
+    DevicePanicNotifierFn *device_panic_notifier;
+    int max_queues;
+    const VuDevIface *vu_iface;
+    VuDev vu_dev;
+    QIOChannel *ioc; /* The I/O channel with the client */
+    QIOChannelSocket *sioc; /* The underlying data channel with the client */
+    /* IOChannel for fd provided via VHOST_USER_SET_SLAVE_REQ_FD */
+    QIOChannel *ioc_slave;
+    QIOChannelSocket *sioc_slave;
+    Coroutine *co_trip; /* coroutine for processing VhostUserMsg */
+    QTAILQ_HEAD(, VuFdWatch) vu_fd_watches;
+    /* restart coroutine co_trip if AIOContext is changed */
+    bool aio_context_changed;
+    bool processing_msg;
+};
+
+bool vhost_user_server_start(VuServer *server,
+                             SocketAddress *unix_socket,
+                             AioContext *ctx,
+                             uint16_t max_queues,
+                             DevicePanicNotifierFn *device_panic_notifier,
+                             const VuDevIface *vu_iface,
+                             Error **errp);
+
+void vhost_user_server_stop(VuServer *server);
+
+void vhost_user_server_set_aio_context(VuServer *server, AioContext *ctx);
+
+#endif /* VHOST_USER_SERVER_H */
diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/util/vhost-user-server.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Sharing QEMU devices via vhost-user protocol
+ *
+ * Copyright (c) Coiby Xu <coiby.xu@gmail.com>.
+ * Copyright (c) 2020 Red Hat, Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
+#include "vhost-user-server.h"
+
+static void vmsg_close_fds(VhostUserMsg *vmsg)
+{
+    int i;
+    for (i = 0; i < vmsg->fd_num; i++) {
+        close(vmsg->fds[i]);
+    }
+}
+
+static void vmsg_unblock_fds(VhostUserMsg *vmsg)
+{
+    int i;
+    for (i = 0; i < vmsg->fd_num; i++) {
+        qemu_set_nonblock(vmsg->fds[i]);
+    }
+}
+
+static void vu_accept(QIONetListener *listener, QIOChannelSocket *sioc,
+                      gpointer opaque);
+
+static void close_client(VuServer *server)
+{
+    /*
+     * Before closing the client
+     *
+     * 1. Let vu_client_trip stop processing new vhost-user msg
+     *
+     * 2. remove kick_handler
+     *
+     * 3. wait for the kick handler to be finished
+     *
+     * 4. wait for the current vhost-user msg to be finished processing
+     */
+
+    QIOChannelSocket *sioc = server->sioc;
+    /* When this is set vu_client_trip will stop new processing vhost-user message */
+    server->sioc = NULL;
+
+    VuFdWatch *vu_fd_watch, *next;
+    QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
+        aio_set_fd_handler(server->ioc->ctx, vu_fd_watch->fd, true, NULL,
+                           NULL, NULL, NULL);
+    }
+
+    while (!QTAILQ_EMPTY(&server->vu_fd_watches)) {
+        QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
+            if (!vu_fd_watch->processing) {
+                QTAILQ_REMOVE(&server->vu_fd_watches, vu_fd_watch, next);
+                g_free(vu_fd_watch);
+            }
+        }
+    }
+
+    while (server->processing_msg) {
+        if (server->ioc->read_coroutine) {
+            server->ioc->read_coroutine = NULL;
+            qio_channel_set_aio_fd_handler(server->ioc, server->ioc->ctx, NULL,
+                                           NULL, server->ioc);
+            server->processing_msg = false;
+        }
+    }
+
+    vu_deinit(&server->vu_dev);
+    object_unref(OBJECT(sioc));
+    object_unref(OBJECT(server->ioc));
+}
+
+static void panic_cb(VuDev *vu_dev, const char *buf)
+{
+    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
+
+    /* avoid while loop in close_client */
+    server->processing_msg = false;
+
+    if (buf) {
+        error_report("vu_panic: %s", buf);
+    }
+
+    if (server->sioc) {
+        close_client(server);
+    }
+
+    if (server->device_panic_notifier) {
+        server->device_panic_notifier(server);
+    }
+
+    /*
+     * Set the callback function for network listener so another
+     * vhost-user client can connect to this server
+     */
+    qio_net_listener_set_client_func(server->listener,
+                                     vu_accept,
+                                     server,
+                                     NULL);
+}
+
+static bool coroutine_fn
+vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg *vmsg)
+{
+    struct iovec iov = {
+        .iov_base = (char *)vmsg,
+        .iov_len = VHOST_USER_HDR_SIZE,
+    };
+    int rc, read_bytes = 0;
+    Error *local_err = NULL;
+    /*
+     * Store fds/nfds returned from qio_channel_readv_full into
+     * temporary variables.
+     *
+     * VhostUserMsg is a packed structure, gcc will complain about passing
+     * pointer to a packed structure member if we pass &VhostUserMsg.fd_num
+     * and &VhostUserMsg.fds directly when calling qio_channel_readv_full,
+     * thus two temporary variables nfds and fds are used here.
+     */
+    size_t nfds = 0, nfds_t = 0;
+    const size_t max_fds = G_N_ELEMENTS(vmsg->fds);
+    int *fds_t = NULL;
+    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
+    QIOChannel *ioc = server->ioc;
+
+    if (!ioc) {
+        error_report_err(local_err);
+        goto fail;
+    }
+
+    assert(qemu_in_coroutine());
+    do {
+        /*
+         * qio_channel_readv_full may have short reads, keeping calling it
+         * until getting VHOST_USER_HDR_SIZE or 0 bytes in total
+         */
+        rc = qio_channel_readv_full(ioc, &iov, 1, &fds_t, &nfds_t, &local_err);
+        if (rc < 0) {
+            if (rc == QIO_CHANNEL_ERR_BLOCK) {
+                qio_channel_yield(ioc, G_IO_IN);
+                continue;
+            } else {
+                error_report_err(local_err);
+                return false;
+            }
+        }
+        read_bytes += rc;
+        if (nfds_t > 0) {
+            if (nfds + nfds_t > max_fds) {
+                error_report("A maximum of %zu fds are allowed, "
+                             "however got %zu fds now",
+                             max_fds, nfds + nfds_t);
+                goto fail;
+            }
+            memcpy(vmsg->fds + nfds, fds_t,
+                   nfds_t *sizeof(vmsg->fds[0]));
+            nfds += nfds_t;
+            g_free(fds_t);
+        }
+        if (read_bytes == VHOST_USER_HDR_SIZE || rc == 0) {
+            break;
+        }
+        iov.iov_base = (char *)vmsg + read_bytes;
+        iov.iov_len = VHOST_USER_HDR_SIZE - read_bytes;
+    } while (true);
+
+    vmsg->fd_num = nfds;
+    /* qio_channel_readv_full will make socket fds blocking, unblock them */
+    vmsg_unblock_fds(vmsg);
+    if (vmsg->size > sizeof(vmsg->payload)) {
+        error_report("Error: too big message request: %d, "
+                     "size: vmsg->size: %u, "
+                     "while sizeof(vmsg->payload) = %zu",
+                     vmsg->request, vmsg->size, sizeof(vmsg->payload));
+        goto fail;
+    }
+
+    struct iovec iov_payload = {
+        .iov_base = (char *)&vmsg->payload,
+        .iov_len = vmsg->size,
+    };
+    if (vmsg->size) {
+        rc = qio_channel_readv_all_eof(ioc, &iov_payload, 1, &local_err);
+        if (rc == -1) {
+            error_report_err(local_err);
+            goto fail;
+        }
+    }
+
+    return true;
+
+fail:
+    vmsg_close_fds(vmsg);
+
+    return false;
+}
+
+
+static void vu_client_start(VuServer *server);
+static coroutine_fn void vu_client_trip(void *opaque)
+{
+    VuServer *server = opaque;
+
+    while (!server->aio_context_changed && server->sioc) {
+        server->processing_msg = true;
+        vu_dispatch(&server->vu_dev);
+        server->processing_msg = false;
+    }
+
+    if (server->aio_context_changed && server->sioc) {
+        server->aio_context_changed = false;
+        vu_client_start(server);
+    }
+}
+
+static void vu_client_start(VuServer *server)
+{
+    server->co_trip = qemu_coroutine_create(vu_client_trip, server);
+    aio_co_enter(server->ctx, server->co_trip);
+}
+
+/*
+ * a wrapper for vu_kick_cb
+ *
+ * since aio_dispatch can only pass one user data pointer to the
+ * callback function, pack VuDev and pvt into a struct. Then unpack it
+ * and pass them to vu_kick_cb
+ */
+static void kick_handler(void *opaque)
+{
+    VuFdWatch *vu_fd_watch = opaque;
+    vu_fd_watch->processing = true;
+    vu_fd_watch->cb(vu_fd_watch->vu_dev, 0, vu_fd_watch->pvt);
+    vu_fd_watch->processing = false;
+}
+
+
+static VuFdWatch *find_vu_fd_watch(VuServer *server, int fd)
+{
+
+    VuFdWatch *vu_fd_watch, *next;
+    QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
+        if (vu_fd_watch->fd == fd) {
+            return vu_fd_watch;
+        }
+    }
+    return NULL;
+}
+
+static void
+set_watch(VuDev *vu_dev, int fd, int vu_evt,
+          vu_watch_cb cb, void *pvt)
+{
+
+    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
+    g_assert(vu_dev);
+    g_assert(fd >= 0);
+    g_assert(cb);
+
+    VuFdWatch *vu_fd_watch = find_vu_fd_watch(server, fd);
+
+    if (!vu_fd_watch) {
+        VuFdWatch *vu_fd_watch = g_new0(VuFdWatch, 1);
+
+        QTAILQ_INSERT_TAIL(&server->vu_fd_watches, vu_fd_watch, next);
+
+        vu_fd_watch->fd = fd;
+        vu_fd_watch->cb = cb;
+        qemu_set_nonblock(fd);
+        aio_set_fd_handler(server->ioc->ctx, fd, true, kick_handler,
+                           NULL, NULL, vu_fd_watch);
+        vu_fd_watch->vu_dev = vu_dev;
+        vu_fd_watch->pvt = pvt;
+    }
+}
+
+
+static void remove_watch(VuDev *vu_dev, int fd)
+{
+    VuServer *server;
+    g_assert(vu_dev);
+    g_assert(fd >= 0);
+
+    server = container_of(vu_dev, VuServer, vu_dev);
+
+    VuFdWatch *vu_fd_watch = find_vu_fd_watch(server, fd);
+
+    if (!vu_fd_watch) {
+        return;
+    }
+    aio_set_fd_handler(server->ioc->ctx, fd, true, NULL, NULL, NULL, NULL);
+
+    QTAILQ_REMOVE(&server->vu_fd_watches, vu_fd_watch, next);
+    g_free(vu_fd_watch);
+}
+
+
+static void vu_accept(QIONetListener *listener, QIOChannelSocket *sioc,
+                      gpointer opaque)
+{
+    VuServer *server = opaque;
+
+    if (server->sioc) {
+        warn_report("Only one vhost-user client is allowed to "
+                    "connect the server one time");
+        return;
+    }
+
+    if (!vu_init(&server->vu_dev, server->max_queues, sioc->fd, panic_cb,
+                 vu_message_read, set_watch, remove_watch, server->vu_iface)) {
+        error_report("Failed to initialize libvhost-user");
+        return;
+    }
+
+    /*
+     * Unset the callback function for network listener to make another
+     * vhost-user client keeping waiting until this client disconnects
+     */
+    qio_net_listener_set_client_func(server->listener,
+                                     NULL,
+                                     NULL,
+                                     NULL);
+    server->sioc = sioc;
+    /*
+     * Increase the object reference, so sioc will not freed by
+     * qio_net_listener_channel_func which will call object_unref(OBJECT(sioc))
+     */
+    object_ref(OBJECT(server->sioc));
+    qio_channel_set_name(QIO_CHANNEL(sioc), "vhost-user client");
+    server->ioc = QIO_CHANNEL(sioc);
+    object_ref(OBJECT(server->ioc));
+    qio_channel_attach_aio_context(server->ioc, server->ctx);
+    qio_channel_set_blocking(QIO_CHANNEL(server->sioc), false, NULL);
+    vu_client_start(server);
+}
+
+
+void vhost_user_server_stop(VuServer *server)
+{
+    if (server->sioc) {
+        close_client(server);
+    }
+
+    if (server->listener) {
+        qio_net_listener_disconnect(server->listener);
+        object_unref(OBJECT(server->listener));
+    }
+
+}
+
+void vhost_user_server_set_aio_context(VuServer *server, AioContext *ctx)
+{
+    VuFdWatch *vu_fd_watch, *next;
+    void *opaque = NULL;
+    IOHandler *io_read = NULL;
+    bool attach;
+
+    server->ctx = ctx ? ctx : qemu_get_aio_context();
+
+    if (!server->sioc) {
+        /* not yet serving any client*/
+        return;
+    }
+
+    if (ctx) {
+        qio_channel_attach_aio_context(server->ioc, ctx);
+        server->aio_context_changed = true;
+        io_read = kick_handler;
+        attach = true;
+    } else {
+        qio_channel_detach_aio_context(server->ioc);
+        /* server->ioc->ctx keeps the old AioConext */
+        ctx = server->ioc->ctx;
+        attach = false;
+    }
+
+    QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
+        if (vu_fd_watch->cb) {
+            opaque = attach ? vu_fd_watch : NULL;
+            aio_set_fd_handler(ctx, vu_fd_watch->fd, true,
+                               io_read, NULL, NULL,
+                               opaque);
+        }
+    }
+}
+
+
+bool vhost_user_server_start(VuServer *server,
+                             SocketAddress *socket_addr,
+                             AioContext *ctx,
+                             uint16_t max_queues,
+                             DevicePanicNotifierFn *device_panic_notifier,
+                             const VuDevIface *vu_iface,
+                             Error **errp)
+{
+    QIONetListener *listener = qio_net_listener_new();
+    if (qio_net_listener_open_sync(listener, socket_addr, 1,
+                                   errp) < 0) {
+        object_unref(OBJECT(listener));
+        return false;
+    }
+
+    /* zero out unspecified fileds */
+    *server = (VuServer) {
+        .listener              = listener,
+        .vu_iface              = vu_iface,
+        .max_queues            = max_queues,
+        .ctx                   = ctx,
+        .device_panic_notifier = device_panic_notifier,
+    };
+
+    qio_net_listener_set_name(server->listener, "vhost-user-backend-listener");
+
+    qio_net_listener_set_client_func(server->listener,
+                                     vu_accept,
+                                     server,
+                                     NULL);
+
+    QTAILQ_INIT(&server->vu_fd_watches);
+    return true;
+}
diff --git a/util/meson.build b/util/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/util/meson.build
+++ b/util/meson.build
@@ -XXX,XX +XXX,XX @@ if have_block
   util_ss.add(files('main-loop.c'))
   util_ss.add(files('nvdimm-utils.c'))
   util_ss.add(files('qemu-coroutine.c', 'qemu-coroutine-lock.c', 'qemu-coroutine-io.c'))
+  util_ss.add(when: 'CONFIG_LINUX', if_true: files('vhost-user-server.c'))
   util_ss.add(files('qemu-coroutine-sleep.c'))
   util_ss.add(files('qemu-co-shared-resource.c'))
   util_ss.add(files('thread-pool.c', 'qemu-timer.c'))
-- 
2.26.2

From: Coiby Xu <coiby.xu@gmail.com>

Move the constants from hw/core/qdev-properties.c to
util/block-helpers.h so that knowledge of the min/max values is

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
Message-id: 20200918080912.321299-5-coiby.xu@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 util/block-helpers.h             | 19 +++++++++++++
 hw/core/qdev-properties-system.c | 31 ++++-----------------
 util/block-helpers.c             | 46 ++++++++++++++++++++++++++++++++
 util/meson.build                 |  1 +
 4 files changed, 71 insertions(+), 26 deletions(-)
 create mode 100644 util/block-helpers.h
 create mode 100644 util/block-helpers.c

diff --git a/util/block-helpers.h b/util/block-helpers.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/util/block-helpers.h
@@ -XXX,XX +XXX,XX @@
+#ifndef BLOCK_HELPERS_H
+#define BLOCK_HELPERS_H
+
+#include "qemu/units.h"
+
+/* lower limit is sector size */
+#define MIN_BLOCK_SIZE          INT64_C(512)
+#define MIN_BLOCK_SIZE_STR      "512 B"
+/*
+ * upper limit is arbitrary, 2 MiB looks sufficient for all sensible uses, and
+ * matches qcow2 cluster size limit
+ */
+#define MAX_BLOCK_SIZE          (2 * MiB)
+#define MAX_BLOCK_SIZE_STR      "2 MiB"
+
+void check_block_size(const char *id, const char *name, int64_t value,
+                      Error **errp);
+
+#endif /* BLOCK_HELPERS_H */
diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/qdev-properties-system.c
+++ b/hw/core/qdev-properties-system.c
@@ -XXX,XX +XXX,XX @@
 #include "sysemu/blockdev.h"
 #include "net/net.h"
 #include "hw/pci/pci.h"
+#include "util/block-helpers.h"
 
 static bool check_prop_still_unset(DeviceState *dev, const char *name,
                                    const void *old_val, const char *new_val,
@@ -XXX,XX +XXX,XX @@ const PropertyInfo qdev_prop_losttickpolicy = {
 
 /* --- blocksize --- */
 
-/* lower limit is sector size */
-#define MIN_BLOCK_SIZE          512
-#define MIN_BLOCK_SIZE_STR      "512 B"
-/*
- * upper limit is arbitrary, 2 MiB looks sufficient for all sensible uses, and
- * matches qcow2 cluster size limit
- */
-#define MAX_BLOCK_SIZE          (2 * MiB)
-#define MAX_BLOCK_SIZE_STR      "2 MiB"
-
 static void set_blocksize(Object *obj, Visitor *v, const char *name,
                           void *opaque, Error **errp)
 {
@@ -XXX,XX +XXX,XX @@ static void set_blocksize(Object *obj, Visitor *v, const char *name,
     Property *prop = opaque;
     uint32_t *ptr = qdev_get_prop_ptr(dev, prop);
     uint64_t value;
+    Error *local_err = NULL;
 
     if (dev->realized) {
         qdev_prop_set_after_realize(dev, name, errp);
@@ -XXX,XX +XXX,XX @@ static void set_blocksize(Object *obj, Visitor *v, const char *name,
     if (!visit_type_size(v, name, &value, errp)) {
         return;
     }
-    /* value of 0 means "unset" */
-    if (value && (value < MIN_BLOCK_SIZE || value > MAX_BLOCK_SIZE)) {
-        error_setg(errp,
-                   "Property %s.%s doesn't take value %" PRIu64
-                   " (minimum: " MIN_BLOCK_SIZE_STR
-                   ", maximum: " MAX_BLOCK_SIZE_STR ")",
-                   dev->id ? : "", name, value);
+    check_block_size(dev->id ? : "", name, value, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
         return;
     }
-
-    /* We rely on power-of-2 blocksizes for bitmasks */
-    if ((value & (value - 1)) != 0) {
-        error_setg(errp,
-                  "Property %s.%s doesn't take value '%" PRId64 "', "
-                  "it's not a power of 2", dev->id ?: "", name, (int64_t)value);
-        return;
-    }
-
     *ptr = value;
 }
 
diff --git a/util/block-helpers.c b/util/block-helpers.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/util/block-helpers.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Block utility functions
+ *
+ * Copyright IBM, Corp. 2011
+ * Copyright (c) 2020 Coiby Xu <coiby.xu@gmail.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qapi/qmp/qerror.h"
+#include "block-helpers.h"
+
+/**
+ * check_block_size:
+ * @id: The unique ID of the object
+ * @name: The name of the property being validated
+ * @value: The block size in bytes
+ * @errp: A pointer to an area to store an error
+ *
+ * This function checks that the block size meets the following conditions:
+ * 1. At least MIN_BLOCK_SIZE
+ * 2. No larger than MAX_BLOCK_SIZE
+ * 3. A power of 2
+ */
+void check_block_size(const char *id, const char *name, int64_t value,
+                      Error **errp)
+{
+    /* value of 0 means "unset" */
+    if (value && (value < MIN_BLOCK_SIZE || value > MAX_BLOCK_SIZE)) {
+        error_setg(errp, QERR_PROPERTY_VALUE_OUT_OF_RANGE,
+                   id, name, value, MIN_BLOCK_SIZE, MAX_BLOCK_SIZE);
+        return;
+    }
+
+    /* We rely on power-of-2 blocksizes for bitmasks */
+    if ((value & (value - 1)) != 0) {
+        error_setg(errp,
+                   "Property %s.%s doesn't take value '%" PRId64
+                   "', it's not a power of 2",
+                   id, name, value);
+        return;
+    }
+}
diff --git a/util/meson.build b/util/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/util/meson.build
+++ b/util/meson.build
@@ -XXX,XX +XXX,XX @@ if have_block
   util_ss.add(files('nvdimm-utils.c'))
   util_ss.add(files('qemu-coroutine.c', 'qemu-coroutine-lock.c', 'qemu-coroutine-io.c'))
   util_ss.add(when: 'CONFIG_LINUX', if_true: files('vhost-user-server.c'))
+  util_ss.add(files('block-helpers.c'))
   util_ss.add(files('qemu-coroutine-sleep.c'))
   util_ss.add(files('qemu-co-shared-resource.c'))
   util_ss.add(files('thread-pool.c', 'qemu-timer.c'))
-- 
2.26.2

From: Coiby Xu <coiby.xu@gmail.com>

By making use of libvhost-user, block device drive can be shared to
the connected vhost-user client. Only one client can connect to the
server one time.

Since vhost-user-server needs a block drive to be created first, delay
the creation of this object.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20200918080912.321299-6-coiby.xu@gmail.com
[Shorten "vhost_user_blk_server" string to "vhost_user_blk" to avoid the
following compiler warning:
../block/export/vhost-user-blk-server.c:178:50: error: ‘%s’ directive output truncated writing 21 bytes into a region of size 20 [-Werror=format-truncation=]
and fix "Invalid size %ld ..." ssize_t format string arguments for
32-bit hosts.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/export/vhost-user-blk-server.h |  36 ++
 block/export/vhost-user-blk-server.c | 661 +++++++++++++++++++++++++++
 softmmu/vl.c                         |   4 +
 block/meson.build                    |   1 +
 4 files changed, 702 insertions(+)
 create mode 100644 block/export/vhost-user-blk-server.h
 create mode 100644 block/export/vhost-user-blk-server.c

diff --git a/block/export/vhost-user-blk-server.h b/block/export/vhost-user-blk-server.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/block/export/vhost-user-blk-server.h
@@ -XXX,XX +XXX,XX @@
+/*
+ * Sharing QEMU block devices via vhost-user protocal
+ *
+ * Copyright (c) Coiby Xu <coiby.xu@gmail.com>.
+ * Copyright (c) 2020 Red Hat, Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#ifndef VHOST_USER_BLK_SERVER_H
+#define VHOST_USER_BLK_SERVER_H
+#include "util/vhost-user-server.h"
+
+typedef struct VuBlockDev VuBlockDev;
+#define TYPE_VHOST_USER_BLK_SERVER "vhost-user-blk-server"
+#define VHOST_USER_BLK_SERVER(obj) \
+   OBJECT_CHECK(VuBlockDev, obj, TYPE_VHOST_USER_BLK_SERVER)
+
+/* vhost user block device */
+struct VuBlockDev {
+    Object parent_obj;
+    char *node_name;
+    SocketAddress *addr;
+    AioContext *ctx;
+    VuServer vu_server;
+    bool running;
+    uint32_t blk_size;
+    BlockBackend *backend;
+    QIOChannelSocket *sioc;
+    QTAILQ_ENTRY(VuBlockDev) next;
+    struct virtio_blk_config blkcfg;
+    bool writable;
+};
+
+#endif /* VHOST_USER_BLK_SERVER_H */
diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/block/export/vhost-user-blk-server.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Sharing QEMU block devices via vhost-user protocal
+ *
+ * Parts of the code based on nbd/server.c.
+ *
+ * Copyright (c) Coiby Xu <coiby.xu@gmail.com>.
+ * Copyright (c) 2020 Red Hat, Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include "block/block.h"
+#include "vhost-user-blk-server.h"
+#include "qapi/error.h"
+#include "qom/object_interfaces.h"
+#include "sysemu/block-backend.h"
+#include "util/block-helpers.h"
+
+enum {
+    VHOST_USER_BLK_MAX_QUEUES = 1,
+};
+struct virtio_blk_inhdr {
+    unsigned char status;
+};
+
+typedef struct VuBlockReq {
+    VuVirtqElement *elem;
+    int64_t sector_num;
+    size_t size;
+    struct virtio_blk_inhdr *in;
+    struct virtio_blk_outhdr out;
+    VuServer *server;
+    struct VuVirtq *vq;
+} VuBlockReq;
+
+static void vu_block_req_complete(VuBlockReq *req)
+{
+    VuDev *vu_dev = &req->server->vu_dev;
+
+    /* IO size with 1 extra status byte */
+    vu_queue_push(vu_dev, req->vq, req->elem, req->size + 1);
+    vu_queue_notify(vu_dev, req->vq);
+
+    if (req->elem) {
+        free(req->elem);
+    }
+
+    g_free(req);
+}
+
+static VuBlockDev *get_vu_block_device_by_server(VuServer *server)
+{
+    return container_of(server, VuBlockDev, vu_server);
+}
+
+static int coroutine_fn
+vu_block_discard_write_zeroes(VuBlockReq *req, struct iovec *iov,
+                              uint32_t iovcnt, uint32_t type)
+{
+    struct virtio_blk_discard_write_zeroes desc;
+    ssize_t size = iov_to_buf(iov, iovcnt, 0, &desc, sizeof(desc));
+    if (unlikely(size != sizeof(desc))) {
+        error_report("Invalid size %zd, expect %zu", size, sizeof(desc));
+        return -EINVAL;
+    }
+
+    VuBlockDev *vdev_blk = get_vu_block_device_by_server(req->server);
+    uint64_t range[2] = { le64_to_cpu(desc.sector) << 9,
+                          le32_to_cpu(desc.num_sectors) << 9 };
+    if (type == VIRTIO_BLK_T_DISCARD) {
+        if (blk_co_pdiscard(vdev_blk->backend, range[0], range[1]) == 0) {
+            return 0;
+        }
+    } else if (type == VIRTIO_BLK_T_WRITE_ZEROES) {
+        if (blk_co_pwrite_zeroes(vdev_blk->backend,
+                                 range[0], range[1], 0) == 0) {
+            return 0;
+        }
+    }
+
+    return -EINVAL;
+}
+
+static void coroutine_fn vu_block_flush(VuBlockReq *req)
+{
+    VuBlockDev *vdev_blk = get_vu_block_device_by_server(req->server);
+    BlockBackend *backend = vdev_blk->backend;
+    blk_co_flush(backend);
+}
+
+struct req_data {
+    VuServer *server;
+    VuVirtq *vq;
+    VuVirtqElement *elem;
+};
+
+static void coroutine_fn vu_block_virtio_process_req(void *opaque)
+{
+    struct req_data *data = opaque;
+    VuServer *server = data->server;
+    VuVirtq *vq = data->vq;
+    VuVirtqElement *elem = data->elem;
+    uint32_t type;
+    VuBlockReq *req;
+
+    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
+    BlockBackend *backend = vdev_blk->backend;
+
+    struct iovec *in_iov = elem->in_sg;
+    struct iovec *out_iov = elem->out_sg;
+    unsigned in_num = elem->in_num;
+    unsigned out_num = elem->out_num;
+    /* refer to hw/block/virtio_blk.c */
+    if (elem->out_num < 1 || elem->in_num < 1) {
+        error_report("virtio-blk request missing headers");
+        free(elem);
+        return;
+    }
+
+    req = g_new0(VuBlockReq, 1);
+    req->server = server;
+    req->vq = vq;
+    req->elem = elem;
+
+    if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
+                            sizeof(req->out)) != sizeof(req->out))) {
+        error_report("virtio-blk request outhdr too short");
+        goto err;
+    }
+
+    iov_discard_front(&out_iov, &out_num, sizeof(req->out));
+
+    if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
+        error_report("virtio-blk request inhdr too short");
+        goto err;
+    }
+
+    /* We always touch the last byte, so just see how big in_iov is.  */
+    req->in = (void *)in_iov[in_num - 1].iov_base
+              + in_iov[in_num - 1].iov_len
+              - sizeof(struct virtio_blk_inhdr);
+    iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr));
+
+    type = le32_to_cpu(req->out.type);
+    switch (type & ~VIRTIO_BLK_T_BARRIER) {
+    case VIRTIO_BLK_T_IN:
+    case VIRTIO_BLK_T_OUT: {
+        ssize_t ret = 0;
+        bool is_write = type & VIRTIO_BLK_T_OUT;
+        req->sector_num = le64_to_cpu(req->out.sector);
+
+        int64_t offset = req->sector_num * vdev_blk->blk_size;
+        QEMUIOVector qiov;
+        if (is_write) {
+            qemu_iovec_init_external(&qiov, out_iov, out_num);
+            ret = blk_co_pwritev(backend, offset, qiov.size,
+                                 &qiov, 0);
+        } else {
+            qemu_iovec_init_external(&qiov, in_iov, in_num);
+            ret = blk_co_preadv(backend, offset, qiov.size,
+                                &qiov, 0);
+        }
+        if (ret >= 0) {
+            req->in->status = VIRTIO_BLK_S_OK;
+        } else {
+            req->in->status = VIRTIO_BLK_S_IOERR;
+        }
+        break;
+    }
+    case VIRTIO_BLK_T_FLUSH:
+        vu_block_flush(req);
+        req->in->status = VIRTIO_BLK_S_OK;
+        break;
+    case VIRTIO_BLK_T_GET_ID: {
+        size_t size = MIN(iov_size(&elem->in_sg[0], in_num),
+                          VIRTIO_BLK_ID_BYTES);
+        snprintf(elem->in_sg[0].iov_base, size, "%s", "vhost_user_blk");
+        req->in->status = VIRTIO_BLK_S_OK;
+        req->size = elem->in_sg[0].iov_len;
+        break;
+    }
+    case VIRTIO_BLK_T_DISCARD:
+    case VIRTIO_BLK_T_WRITE_ZEROES: {
+        int rc;
+        rc = vu_block_discard_write_zeroes(req, &elem->out_sg[1],
+                                           out_num, type);
+        if (rc == 0) {
+            req->in->status = VIRTIO_BLK_S_OK;
+        } else {
+            req->in->status = VIRTIO_BLK_S_IOERR;
+        }
+        break;
+    }
+    default:
+        req->in->status = VIRTIO_BLK_S_UNSUPP;
+        break;
+    }
+
+    vu_block_req_complete(req);
+    return;
+
+err:
+    free(elem);
+    g_free(req);
+    return;
+}
+
+static void vu_block_process_vq(VuDev *vu_dev, int idx)
+{
+    VuServer *server;
+    VuVirtq *vq;
+    struct req_data *req_data;
+
+    server = container_of(vu_dev, VuServer, vu_dev);
+    assert(server);
+
+    vq = vu_get_queue(vu_dev, idx);
+    assert(vq);
+    VuVirtqElement *elem;
+    while (1) {
+        elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement) +
+                                    sizeof(VuBlockReq));
+        if (elem) {
+            req_data = g_new0(struct req_data, 1);
+            req_data->server = server;
+            req_data->vq = vq;
+            req_data->elem = elem;
+            Coroutine *co = qemu_coroutine_create(vu_block_virtio_process_req,
+                                                  req_data);
+            aio_co_enter(server->ioc->ctx, co);
+        } else {
+            break;
+        }
+    }
+}
+
+static void vu_block_queue_set_started(VuDev *vu_dev, int idx, bool started)
+{
+    VuVirtq *vq;
+
+    assert(vu_dev);
+
+    vq = vu_get_queue(vu_dev, idx);
+    vu_set_queue_handler(vu_dev, vq, started ? vu_block_process_vq : NULL);
+}
+
+static uint64_t vu_block_get_features(VuDev *dev)
+{
+    uint64_t features;
+    VuServer *server = container_of(dev, VuServer, vu_dev);
+    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
+    features = 1ull << VIRTIO_BLK_F_SIZE_MAX |
+               1ull << VIRTIO_BLK_F_SEG_MAX |
+               1ull << VIRTIO_BLK_F_TOPOLOGY |
+               1ull << VIRTIO_BLK_F_BLK_SIZE |
+               1ull << VIRTIO_BLK_F_FLUSH |
+               1ull << VIRTIO_BLK_F_DISCARD |
+               1ull << VIRTIO_BLK_F_WRITE_ZEROES |
+               1ull << VIRTIO_BLK_F_CONFIG_WCE |
+               1ull << VIRTIO_F_VERSION_1 |
+               1ull << VIRTIO_RING_F_INDIRECT_DESC |
+               1ull << VIRTIO_RING_F_EVENT_IDX |
+               1ull << VHOST_USER_F_PROTOCOL_FEATURES;
+
+    if (!vdev_blk->writable) {
+        features |= 1ull << VIRTIO_BLK_F_RO;
+    }
+
+    return features;
+}
+
+static uint64_t vu_block_get_protocol_features(VuDev *dev)
+{
+    return 1ull << VHOST_USER_PROTOCOL_F_CONFIG |
+           1ull << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD;
+}
+
+static int
+vu_block_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
+{
+    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
+    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
+    memcpy(config, &vdev_blk->blkcfg, len);
+
+    return 0;
+}
+
+static int
+vu_block_set_config(VuDev *vu_dev, const uint8_t *data,
+                    uint32_t offset, uint32_t size, uint32_t flags)
+{
+    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
+    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
+    uint8_t wce;
+
+    /* don't support live migration */
+    if (flags != VHOST_SET_CONFIG_TYPE_MASTER) {
+        return -EINVAL;
+    }
+
+    if (offset != offsetof(struct virtio_blk_config, wce) ||
+        size != 1) {
+        return -EINVAL;
+    }
+
+    wce = *data;
+    vdev_blk->blkcfg.wce = wce;
+    blk_set_enable_write_cache(vdev_blk->backend, wce);
+    return 0;
+}
+
+/*
+ * When the client disconnects, it sends a VHOST_USER_NONE request
+ * and vu_process_message will simple call exit which cause the VM
+ * to exit abruptly.
+ * To avoid this issue,  process VHOST_USER_NONE request ahead
+ * of vu_process_message.
+ *
+ */
+static int vu_block_process_msg(VuDev *dev, VhostUserMsg *vmsg, int *do_reply)
+{
+    if (vmsg->request == VHOST_USER_NONE) {
+        dev->panic(dev, "disconnect");
+        return true;
+    }
+    return false;
+}
+
+static const VuDevIface vu_block_iface = {
+    .get_features          = vu_block_get_features,
+    .queue_set_started     = vu_block_queue_set_started,
+    .get_protocol_features = vu_block_get_protocol_features,
+    .get_config            = vu_block_get_config,
+    .set_config            = vu_block_set_config,
+    .process_msg           = vu_block_process_msg,
+};
+
+static void blk_aio_attached(AioContext *ctx, void *opaque)
+{
+    VuBlockDev *vub_dev = opaque;
+    aio_context_acquire(ctx);
+    vhost_user_server_set_aio_context(&vub_dev->vu_server, ctx);
+    aio_context_release(ctx);
+}
+
+static void blk_aio_detach(void *opaque)
+{
+    VuBlockDev *vub_dev = opaque;
+    AioContext *ctx = vub_dev->vu_server.ctx;
+    aio_context_acquire(ctx);
+    vhost_user_server_set_aio_context(&vub_dev->vu_server, NULL);
+    aio_context_release(ctx);
+}
+
+static void
+vu_block_initialize_config(BlockDriverState *bs,
+                           struct virtio_blk_config *config, uint32_t blk_size)
+{
+    config->capacity = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
+    config->blk_size = blk_size;
+    config->size_max = 0;
+    config->seg_max = 128 - 2;
+    config->min_io_size = 1;
+    config->opt_io_size = 1;
+    config->num_queues = VHOST_USER_BLK_MAX_QUEUES;
+    config->max_discard_sectors = 32768;
+    config->max_discard_seg = 1;
+    config->discard_sector_alignment = config->blk_size >> 9;
+    config->max_write_zeroes_sectors = 32768;
+    config->max_write_zeroes_seg = 1;
+}
+
+static VuBlockDev *vu_block_init(VuBlockDev *vu_block_device, Error **errp)
+{
+
+    BlockBackend *blk;
+    Error *local_error = NULL;
+    const char *node_name = vu_block_device->node_name;
+    bool writable = vu_block_device->writable;
+    uint64_t perm = BLK_PERM_CONSISTENT_READ;
+    int ret;
+
+    AioContext *ctx;
+
+    BlockDriverState *bs = bdrv_lookup_bs(node_name, node_name, &local_error);
+
+    if (!bs) {
+        error_propagate(errp, local_error);
+        return NULL;
+    }
+
+    if (bdrv_is_read_only(bs)) {
+        writable = false;
+    }
+
+    if (writable) {
+        perm |= BLK_PERM_WRITE;
+    }
+
+    ctx = bdrv_get_aio_context(bs);
+    aio_context_acquire(ctx);
+    bdrv_invalidate_cache(bs, NULL);
+    aio_context_release(ctx);
+
+    /*
+     * Don't allow resize while the vhost user server is running,
+     * otherwise we don't care what happens with the node.
+     */
+    blk = blk_new(bdrv_get_aio_context(bs), perm,
+                  BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
+                  BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD);
+    ret = blk_insert_bs(blk, bs, errp);
+
+    if (ret < 0) {
+        goto fail;
+    }
+
+    blk_set_enable_write_cache(blk, false);
+
+    blk_set_allow_aio_context_change(blk, true);
+
+    vu_block_device->blkcfg.wce = 0;
+    vu_block_device->backend = blk;
+    if (!vu_block_device->blk_size) {
+        vu_block_device->blk_size = BDRV_SECTOR_SIZE;
+    }
+    vu_block_device->blkcfg.blk_size = vu_block_device->blk_size;
+    blk_set_guest_block_size(blk, vu_block_device->blk_size);
+    vu_block_initialize_config(bs, &vu_block_device->blkcfg,
+                                   vu_block_device->blk_size);
+    return vu_block_device;
+
+fail:
+    blk_unref(blk);
+    return NULL;
+}
+
+static void vu_block_deinit(VuBlockDev *vu_block_device)
+{
+    if (vu_block_device->backend) {
+        blk_remove_aio_context_notifier(vu_block_device->backend, blk_aio_attached,
+                                        blk_aio_detach, vu_block_device);
+    }
+
+    blk_unref(vu_block_device->backend);
+}
+
+static void vhost_user_blk_server_stop(VuBlockDev *vu_block_device)
+{
+    vhost_user_server_stop(&vu_block_device->vu_server);
+    vu_block_deinit(vu_block_device);
+}
+
+static void vhost_user_blk_server_start(VuBlockDev *vu_block_device,
+                                        Error **errp)
+{
+    AioContext *ctx;
+    SocketAddress *addr = vu_block_device->addr;
+
+    if (!vu_block_init(vu_block_device, errp)) {
+        return;
+    }
+
+    ctx = bdrv_get_aio_context(blk_bs(vu_block_device->backend));
+
+    if (!vhost_user_server_start(&vu_block_device->vu_server, addr, ctx,
+                                 VHOST_USER_BLK_MAX_QUEUES,
+                                 NULL, &vu_block_iface,
+                                 errp)) {
+        goto error;
+    }
+
+    blk_add_aio_context_notifier(vu_block_device->backend, blk_aio_attached,
+                                 blk_aio_detach, vu_block_device);
+    vu_block_device->running = true;
+    return;
+
+ error:
+    vu_block_deinit(vu_block_device);
+}
+
+static bool vu_prop_modifiable(VuBlockDev *vus, Error **errp)
+{
+    if (vus->running) {
+            error_setg(errp, "The property can't be modified "
+                       "while the server is running");
+            return false;
+    }
+    return true;
+}
+
+static void vu_set_node_name(Object *obj, const char *value, Error **errp)
+{
+    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
+
+    if (!vu_prop_modifiable(vus, errp)) {
+        return;
+    }
+
+    if (vus->node_name) {
+        g_free(vus->node_name);
+    }
+
+    vus->node_name = g_strdup(value);
+}
+
+static char *vu_get_node_name(Object *obj, Error **errp)
+{
+    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
+    return g_strdup(vus->node_name);
+}
+
+static void free_socket_addr(SocketAddress *addr)
+{
+        g_free(addr->u.q_unix.path);
+        g_free(addr);
+}
+
+static void vu_set_unix_socket(Object *obj, const char *value,
+                               Error **errp)
+{
+    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
+
+    if (!vu_prop_modifiable(vus, errp)) {
+        return;
+    }
+
+    if (vus->addr) {
+        free_socket_addr(vus->addr);
+    }
+
+    SocketAddress *addr = g_new0(SocketAddress, 1);
+    addr->type = SOCKET_ADDRESS_TYPE_UNIX;
+    addr->u.q_unix.path = g_strdup(value);
+    vus->addr = addr;
+}
+
+static char *vu_get_unix_socket(Object *obj, Error **errp)
+{
+    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
+    return g_strdup(vus->addr->u.q_unix.path);
+}
+
+static bool vu_get_block_writable(Object *obj, Error **errp)
+{
+    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
+    return vus->writable;
+}
+
+static void vu_set_block_writable(Object *obj, bool value, Error **errp)
+{
+    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
+
+    if (!vu_prop_modifiable(vus, errp)) {
+            return;
+    }
+
+    vus->writable = value;
+}
+
+static void vu_get_blk_size(Object *obj, Visitor *v, const char *name,
+                            void *opaque, Error **errp)
+{
+    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
+    uint32_t value = vus->blk_size;
+
+    visit_type_uint32(v, name, &value, errp);
+}
+
+static void vu_set_blk_size(Object *obj, Visitor *v, const char *name,
+                            void *opaque, Error **errp)
+{
+    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
+
+    Error *local_err = NULL;
+    uint32_t value;
+
+    if (!vu_prop_modifiable(vus, errp)) {
+            return;
+    }
+
+    visit_type_uint32(v, name, &value, &local_err);
+    if (local_err) {
+        goto out;
+    }
+
+    check_block_size(object_get_typename(obj), name, value, &local_err);
+    if (local_err) {
+        goto out;
+    }
+
+    vus->blk_size = value;
+
+out:
+    error_propagate(errp, local_err);
+}
+
+static void vhost_user_blk_server_instance_finalize(Object *obj)
+{
+    VuBlockDev *vub = VHOST_USER_BLK_SERVER(obj);
+
+    vhost_user_blk_server_stop(vub);
+
+    /*
+     * Unlike object_property_add_str, object_class_property_add_str
+     * doesn't have a release method. Thus manual memory freeing is
+     * needed.
+     */
+    free_socket_addr(vub->addr);
+    g_free(vub->node_name);
+}
+
+static void vhost_user_blk_server_complete(UserCreatable *obj, Error **errp)
+{
+    VuBlockDev *vub = VHOST_USER_BLK_SERVER(obj);
+
+    vhost_user_blk_server_start(vub, errp);
+}
+
+static void vhost_user_blk_server_class_init(ObjectClass *klass,
+                                             void *class_data)
+{
+    UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
+    ucc->complete = vhost_user_blk_server_complete;
+
+    object_class_property_add_bool(klass, "writable",
+                                   vu_get_block_writable,
+                                   vu_set_block_writable);
+
+    object_class_property_add_str(klass, "node-name",
+                                  vu_get_node_name,
+                                  vu_set_node_name);
+
+    object_class_property_add_str(klass, "unix-socket",
+                                  vu_get_unix_socket,
+                                  vu_set_unix_socket);
+
+    object_class_property_add(klass, "logical-block-size", "uint32",
+                              vu_get_blk_size, vu_set_blk_size,
+                              NULL, NULL);
+}
+
+static const TypeInfo vhost_user_blk_server_info = {
+    .name = TYPE_VHOST_USER_BLK_SERVER,
+    .parent = TYPE_OBJECT,
+    .instance_size = sizeof(VuBlockDev),
+    .instance_finalize = vhost_user_blk_server_instance_finalize,
+    .class_init = vhost_user_blk_server_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        {TYPE_USER_CREATABLE},
+        {}
+    },
+};
+
+static void vhost_user_blk_server_register_types(void)
+{
+    type_register_static(&vhost_user_blk_server_info);
+}
+
+type_init(vhost_user_blk_server_register_types)
diff --git a/softmmu/vl.c b/softmmu/vl.c
index XXXXXXX..XXXXXXX 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -XXX,XX +XXX,XX @@ static bool object_create_initial(const char *type, QemuOpts *opts)
     }
 #endif
 
+    /* Reason: vhost-user-blk-server property "node-name" */
+    if (g_str_equal(type, "vhost-user-blk-server")) {
+        return false;
+    }
     /*
      * Reason: filter-* property "netdev" etc.
      */
diff --git a/block/meson.build b/block/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/block/meson.build
+++ b/block/meson.build
@@ -XXX,XX +XXX,XX @@ block_ss.add(when: 'CONFIG_WIN32', if_true: files('file-win32.c', 'win32-aio.c')
 block_ss.add(when: 'CONFIG_POSIX', if_true: [files('file-posix.c'), coref, iokit])
 block_ss.add(when: 'CONFIG_LIBISCSI', if_true: files('iscsi-opts.c'))
 block_ss.add(when: 'CONFIG_LINUX', if_true: files('nvme.c'))
+block_ss.add(when: 'CONFIG_LINUX', if_true: files('export/vhost-user-blk-server.c', '../contrib/libvhost-user/libvhost-user.c'))
 block_ss.add(when: 'CONFIG_REPLICATION', if_true: files('replication.c'))
 block_ss.add(when: 'CONFIG_SHEEPDOG', if_true: files('sheepdog.c'))
 block_ss.add(when: ['CONFIG_LINUX_AIO', libaio], if_true: files('linux-aio.c'))
-- 
2.26.2

From: Coiby Xu <coiby.xu@gmail.com>

Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20200918080912.321299-8-coiby.xu@gmail.com
[Removed reference to vhost-user-blk-test.c, it will be sent in a
separate pull request.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ L: qemu-block@nongnu.org
 S: Supported
 F: tests/image-fuzzer/
 
+Vhost-user block device backend server
+M: Coiby Xu <Coiby.Xu@gmail.com>
+S: Maintained
+F: block/export/vhost-user-blk-server.c
+F: util/vhost-user-server.c
+F: tests/qtest/libqos/vhost-user-blk.c
+
 Replication
 M: Wen Congyang <wencongyang2@huawei.com>
 M: Xie Changlong <xiechanglong.d@gmail.com>
-- 
2.26.2

Explicitly deleting watches is not necessary since libvhost-user calls
remove_watch() during vu_deinit(). Add an assertion to check this
though.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-5-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 util/vhost-user-server.c | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
index XXXXXXX..XXXXXXX 100644
--- a/util/vhost-user-server.c
+++ b/util/vhost-user-server.c
@@ -XXX,XX +XXX,XX @@ static void close_client(VuServer *server)
     /* When this is set vu_client_trip will stop new processing vhost-user message */
     server->sioc = NULL;
 
-    VuFdWatch *vu_fd_watch, *next;
-    QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
-        aio_set_fd_handler(server->ioc->ctx, vu_fd_watch->fd, true, NULL,
-                           NULL, NULL, NULL);
-    }
-
-    while (!QTAILQ_EMPTY(&server->vu_fd_watches)) {
-        QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
-            if (!vu_fd_watch->processing) {
-                QTAILQ_REMOVE(&server->vu_fd_watches, vu_fd_watch, next);
-                g_free(vu_fd_watch);
-            }
-        }
-    }
-
     while (server->processing_msg) {
         if (server->ioc->read_coroutine) {
             server->ioc->read_coroutine = NULL;
@@ -XXX,XX +XXX,XX @@ static void close_client(VuServer *server)
     }
 
     vu_deinit(&server->vu_dev);
+
+    /* vu_deinit() should have called remove_watch() */
+    assert(QTAILQ_EMPTY(&server->vu_fd_watches));
+
     object_unref(OBJECT(sioc));
     object_unref(OBJECT(server->ioc));
 }
-- 
2.26.2

Only one struct is needed per request. Drop req_data and the separate
VuBlockReq instance. Instead let vu_queue_pop() allocate everything at
once.

This fixes the req_data memory leak in vu_block_virtio_process_req().

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-6-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/export/vhost-user-blk-server.c | 68 +++++++++-------------------
 1 file changed, 21 insertions(+), 47 deletions(-)

diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
index XXXXXXX..XXXXXXX 100644
--- a/block/export/vhost-user-blk-server.c
+++ b/block/export/vhost-user-blk-server.c
@@ -XXX,XX +XXX,XX @@ struct virtio_blk_inhdr {
 };
 
 typedef struct VuBlockReq {
-    VuVirtqElement *elem;
+    VuVirtqElement elem;
     int64_t sector_num;
     size_t size;
     struct virtio_blk_inhdr *in;
@@ -XXX,XX +XXX,XX @@ static void vu_block_req_complete(VuBlockReq *req)
     VuDev *vu_dev = &req->server->vu_dev;
 
     /* IO size with 1 extra status byte */
-    vu_queue_push(vu_dev, req->vq, req->elem, req->size + 1);
+    vu_queue_push(vu_dev, req->vq, &req->elem, req->size + 1);
     vu_queue_notify(vu_dev, req->vq);
 
-    if (req->elem) {
-        free(req->elem);
-    }
-
-    g_free(req);
+    free(req);
 }
 
 static VuBlockDev *get_vu_block_device_by_server(VuServer *server)
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_flush(VuBlockReq *req)
     blk_co_flush(backend);
 }
 
-struct req_data {
-    VuServer *server;
-    VuVirtq *vq;
-    VuVirtqElement *elem;
-};
-
 static void coroutine_fn vu_block_virtio_process_req(void *opaque)
 {
-    struct req_data *data = opaque;
-    VuServer *server = data->server;
-    VuVirtq *vq = data->vq;
-    VuVirtqElement *elem = data->elem;
+    VuBlockReq *req = opaque;
+    VuServer *server = req->server;
+    VuVirtqElement *elem = &req->elem;
     uint32_t type;
-    VuBlockReq *req;
 
     VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
     BlockBackend *backend = vdev_blk->backend;
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
     struct iovec *out_iov = elem->out_sg;
     unsigned in_num = elem->in_num;
     unsigned out_num = elem->out_num;
+
     /* refer to hw/block/virtio_blk.c */
     if (elem->out_num < 1 || elem->in_num < 1) {
         error_report("virtio-blk request missing headers");
-        free(elem);
-        return;
+        goto err;
     }
 
-    req = g_new0(VuBlockReq, 1);
-    req->server = server;
-    req->vq = vq;
-    req->elem = elem;
-
     if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
                             sizeof(req->out)) != sizeof(req->out))) {
         error_report("virtio-blk request outhdr too short");
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
 
 err:
     free(elem);
-    g_free(req);
-    return;
 }
 
 static void vu_block_process_vq(VuDev *vu_dev, int idx)
 {
-    VuServer *server;
-    VuVirtq *vq;
-    struct req_data *req_data;
+    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
+    VuVirtq *vq = vu_get_queue(vu_dev, idx);
 
-    server = container_of(vu_dev, VuServer, vu_dev);
-    assert(server);
-
-    vq = vu_get_queue(vu_dev, idx);
-    assert(vq);
-    VuVirtqElement *elem;
     while (1) {
-        elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement) +
-                                    sizeof(VuBlockReq));
-        if (elem) {
-            req_data = g_new0(struct req_data, 1);
-            req_data->server = server;
-            req_data->vq = vq;
-            req_data->elem = elem;
-            Coroutine *co = qemu_coroutine_create(vu_block_virtio_process_req,
-                                                  req_data);
-            aio_co_enter(server->ioc->ctx, co);
-        } else {
+        VuBlockReq *req;
+
+        req = vu_queue_pop(vu_dev, vq, sizeof(VuBlockReq));
+        if (!req) {
             break;
         }
+
+        req->server = server;
+        req->vq = vq;
+
+        Coroutine *co =
+            qemu_coroutine_create(vu_block_virtio_process_req, req);
+        qemu_coroutine_enter(co);
     }
 }
 
-- 
2.26.2

The device panic notifier callback is not used. Drop it.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-7-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 util/vhost-user-server.h             | 3 ---
 block/export/vhost-user-blk-server.c | 3 +--
 util/vhost-user-server.c             | 6 ------
 3 files changed, 1 insertion(+), 11 deletions(-)

diff --git a/util/vhost-user-server.h b/util/vhost-user-server.h
index XXXXXXX..XXXXXXX 100644
--- a/util/vhost-user-server.h
+++ b/util/vhost-user-server.h
@@ -XXX,XX +XXX,XX @@ typedef struct VuFdWatch {
 } VuFdWatch;
 
 typedef struct VuServer VuServer;
-typedef void DevicePanicNotifierFn(VuServer *server);
 
 struct VuServer {
     QIONetListener *listener;
     AioContext *ctx;
-    DevicePanicNotifierFn *device_panic_notifier;
     int max_queues;
     const VuDevIface *vu_iface;
     VuDev vu_dev;
@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
                              SocketAddress *unix_socket,
                              AioContext *ctx,
                              uint16_t max_queues,
-                             DevicePanicNotifierFn *device_panic_notifier,
                              const VuDevIface *vu_iface,
                              Error **errp);
 
diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
index XXXXXXX..XXXXXXX 100644
--- a/block/export/vhost-user-blk-server.c
+++ b/block/export/vhost-user-blk-server.c
@@ -XXX,XX +XXX,XX @@ static void vhost_user_blk_server_start(VuBlockDev *vu_block_device,
     ctx = bdrv_get_aio_context(blk_bs(vu_block_device->backend));
 
     if (!vhost_user_server_start(&vu_block_device->vu_server, addr, ctx,
-                                 VHOST_USER_BLK_MAX_QUEUES,
-                                 NULL, &vu_block_iface,
+                                 VHOST_USER_BLK_MAX_QUEUES, &vu_block_iface,
                                  errp)) {
         goto error;
     }
diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
index XXXXXXX..XXXXXXX 100644
--- a/util/vhost-user-server.c
+++ b/util/vhost-user-server.c
@@ -XXX,XX +XXX,XX @@ static void panic_cb(VuDev *vu_dev, const char *buf)
         close_client(server);
     }
 
-    if (server->device_panic_notifier) {
-        server->device_panic_notifier(server);
-    }
-
     /*
      * Set the callback function for network listener so another
      * vhost-user client can connect to this server
@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
                              SocketAddress *socket_addr,
                              AioContext *ctx,
                              uint16_t max_queues,
-                             DevicePanicNotifierFn *device_panic_notifier,
                              const VuDevIface *vu_iface,
                              Error **errp)
 {
@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
         .vu_iface              = vu_iface,
         .max_queues            = max_queues,
         .ctx                   = ctx,
-        .device_panic_notifier = device_panic_notifier,
     };
 
     qio_net_listener_set_name(server->listener, "vhost-user-backend-listener");
-- 
2.26.2

fds[] is leaked when qio_channel_readv_full() fails.

Use vmsg->fds[] instead of keeping a local fds[] array. Then we can
reuse goto fail to clean up fds. vmsg->fd_num must be zeroed before the
loop to make this safe.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-8-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 util/vhost-user-server.c | 50 ++++++++++++++++++----------------------
 1 file changed, 23 insertions(+), 27 deletions(-)

diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
index XXXXXXX..XXXXXXX 100644
--- a/util/vhost-user-server.c
+++ b/util/vhost-user-server.c
@@ -XXX,XX +XXX,XX @@ vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg *vmsg)
     };
     int rc, read_bytes = 0;
     Error *local_err = NULL;
-    /*
-     * Store fds/nfds returned from qio_channel_readv_full into
-     * temporary variables.
-     *
-     * VhostUserMsg is a packed structure, gcc will complain about passing
-     * pointer to a packed structure member if we pass &VhostUserMsg.fd_num
-     * and &VhostUserMsg.fds directly when calling qio_channel_readv_full,
-     * thus two temporary variables nfds and fds are used here.
-     */
-    size_t nfds = 0, nfds_t = 0;
     const size_t max_fds = G_N_ELEMENTS(vmsg->fds);
-    int *fds_t = NULL;
     VuServer *server = container_of(vu_dev, VuServer, vu_dev);
     QIOChannel *ioc = server->ioc;
 
+    vmsg->fd_num = 0;
     if (!ioc) {
         error_report_err(local_err);
         goto fail;
@@ -XXX,XX +XXX,XX @@ vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg *vmsg)
 
     assert(qemu_in_coroutine());
     do {
+        size_t nfds = 0;
+        int *fds = NULL;
+
         /*
          * qio_channel_readv_full may have short reads, keeping calling it
          * until getting VHOST_USER_HDR_SIZE or 0 bytes in total
          */
-        rc = qio_channel_readv_full(ioc, &iov, 1, &fds_t, &nfds_t, &local_err);
+        rc = qio_channel_readv_full(ioc, &iov, 1, &fds, &nfds, &local_err);
         if (rc < 0) {
             if (rc == QIO_CHANNEL_ERR_BLOCK) {
+                assert(local_err == NULL);
                 qio_channel_yield(ioc, G_IO_IN);
                 continue;
             } else {
                 error_report_err(local_err);
-                return false;
+                goto fail;
             }
         }
-        read_bytes += rc;
-        if (nfds_t > 0) {
-            if (nfds + nfds_t > max_fds) {
+
+        if (nfds > 0) {
+            if (vmsg->fd_num + nfds > max_fds) {
                 error_report("A maximum of %zu fds are allowed, "
                              "however got %zu fds now",
-                             max_fds, nfds + nfds_t);
+                             max_fds, vmsg->fd_num + nfds);
+                g_free(fds);
                 goto fail;
             }
-            memcpy(vmsg->fds + nfds, fds_t,
-                   nfds_t *sizeof(vmsg->fds[0]));
-            nfds += nfds_t;
-            g_free(fds_t);
+            memcpy(vmsg->fds + vmsg->fd_num, fds, nfds * sizeof(vmsg->fds[0]));
+            vmsg->fd_num += nfds;
+            g_free(fds);
         }
-        if (read_bytes == VHOST_USER_HDR_SIZE || rc == 0) {
-            break;
+
+        if (rc == 0) { /* socket closed */
+            goto fail;
         }
-        iov.iov_base = (char *)vmsg + read_bytes;
-        iov.iov_len = VHOST_USER_HDR_SIZE - read_bytes;
-    } while (true);
 
-    vmsg->fd_num = nfds;
+        iov.iov_base += rc;
+        iov.iov_len -= rc;
+        read_bytes += rc;
+    } while (read_bytes != VHOST_USER_HDR_SIZE);
+
     /* qio_channel_readv_full will make socket fds blocking, unblock them */
     vmsg_unblock_fds(vmsg);
     if (vmsg->size > sizeof(vmsg->payload)) {
-- 
2.26.2

The vu_client_trip() coroutine is leaked during AioContext switching. It
is also unsafe to destroy the vu_dev in panic_cb() since its callers
still access it in some cases.

Rework the lifecycle to solve these safety issues.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-10-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 util/vhost-user-server.h             |  29 ++--
 block/export/vhost-user-blk-server.c |   9 +-
 util/vhost-user-server.c             | 245 +++++++++++++++------------
 3 files changed, 155 insertions(+), 128 deletions(-)

diff --git a/util/vhost-user-server.h b/util/vhost-user-server.h
index XXXXXXX..XXXXXXX 100644
--- a/util/vhost-user-server.h
+++ b/util/vhost-user-server.h
@@ -XXX,XX +XXX,XX @@
 #include "qapi/error.h"
 #include "standard-headers/linux/virtio_blk.h"
 
+/* A kick fd that we monitor on behalf of libvhost-user */
 typedef struct VuFdWatch {
     VuDev *vu_dev;
     int fd; /*kick fd*/
     void *pvt;
     vu_watch_cb cb;
-    bool processing;
     QTAILQ_ENTRY(VuFdWatch) next;
 } VuFdWatch;
 
-typedef struct VuServer VuServer;
-
-struct VuServer {
+/**
+ * VuServer:
+ * A vhost-user server instance with user-defined VuDevIface callbacks.
+ * Vhost-user device backends can be implemented using VuServer. VuDevIface
+ * callbacks and virtqueue kicks run in the given AioContext.
+ */
+typedef struct {
     QIONetListener *listener;
+    QEMUBH *restart_listener_bh;
     AioContext *ctx;
     int max_queues;
     const VuDevIface *vu_iface;
+
+    /* Protected by ctx lock */
     VuDev vu_dev;
     QIOChannel *ioc; /* The I/O channel with the client */
     QIOChannelSocket *sioc; /* The underlying data channel with the client */
-    /* IOChannel for fd provided via VHOST_USER_SET_SLAVE_REQ_FD */
-    QIOChannel *ioc_slave;
-    QIOChannelSocket *sioc_slave;
-    Coroutine *co_trip; /* coroutine for processing VhostUserMsg */
     QTAILQ_HEAD(, VuFdWatch) vu_fd_watches;
-    /* restart coroutine co_trip if AIOContext is changed */
-    bool aio_context_changed;
-    bool processing_msg;
-};
+
+    Coroutine *co_trip; /* coroutine for processing VhostUserMsg */
+} VuServer;
 
 bool vhost_user_server_start(VuServer *server,
                              SocketAddress *unix_socket,
@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
 
 void vhost_user_server_stop(VuServer *server);
 
-void vhost_user_server_set_aio_context(VuServer *server, AioContext *ctx);
+void vhost_user_server_attach_aio_context(VuServer *server, AioContext *ctx);
+void vhost_user_server_detach_aio_context(VuServer *server);
 
 #endif /* VHOST_USER_SERVER_H */
diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
index XXXXXXX..XXXXXXX 100644
--- a/block/export/vhost-user-blk-server.c
+++ b/block/export/vhost-user-blk-server.c
@@ -XXX,XX +XXX,XX @@ static const VuDevIface vu_block_iface = {
 static void blk_aio_attached(AioContext *ctx, void *opaque)
 {
     VuBlockDev *vub_dev = opaque;
-    aio_context_acquire(ctx);
-    vhost_user_server_set_aio_context(&vub_dev->vu_server, ctx);
-    aio_context_release(ctx);
+    vhost_user_server_attach_aio_context(&vub_dev->vu_server, ctx);
 }
 
 static void blk_aio_detach(void *opaque)
 {
     VuBlockDev *vub_dev = opaque;
-    AioContext *ctx = vub_dev->vu_server.ctx;
-    aio_context_acquire(ctx);
-    vhost_user_server_set_aio_context(&vub_dev->vu_server, NULL);
-    aio_context_release(ctx);
+    vhost_user_server_detach_aio_context(&vub_dev->vu_server);
 }
 
 static void
diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
index XXXXXXX..XXXXXXX 100644
--- a/util/vhost-user-server.c
+++ b/util/vhost-user-server.c
@@ -XXX,XX +XXX,XX @@
  */
 #include "qemu/osdep.h"
 #include "qemu/main-loop.h"
+#include "block/aio-wait.h"
 #include "vhost-user-server.h"
 
+/*
+ * Theory of operation:
+ *
+ * VuServer is started and stopped by vhost_user_server_start() and
+ * vhost_user_server_stop() from the main loop thread. Starting the server
+ * opens a vhost-user UNIX domain socket and listens for incoming connections.
+ * Only one connection is allowed at a time.
+ *
+ * The connection is handled by the vu_client_trip() coroutine in the
+ * VuServer->ctx AioContext. The coroutine consists of a vu_dispatch() loop
+ * where libvhost-user calls vu_message_read() to receive the next vhost-user
+ * protocol messages over the UNIX domain socket.
+ *
+ * When virtqueues are set up libvhost-user calls set_watch() to monitor kick
+ * fds. These fds are also handled in the VuServer->ctx AioContext.
+ *
+ * Both vu_client_trip() and kick fd monitoring can be stopped by shutting down
+ * the socket connection. Shutting down the socket connection causes
+ * vu_message_read() to fail since no more data can be received from the socket.
+ * After vu_dispatch() fails, vu_client_trip() calls vu_deinit() to stop
+ * libvhost-user before terminating the coroutine. vu_deinit() calls
+ * remove_watch() to stop monitoring kick fds and this stops virtqueue
+ * processing.
+ *
+ * When vu_client_trip() has finished cleaning up it schedules a BH in the main
+ * loop thread to accept the next client connection.
+ *
+ * When libvhost-user detects an error it calls panic_cb() and sets the
+ * dev->broken flag. Both vu_client_trip() and kick fd processing stop when
+ * the dev->broken flag is set.
+ *
+ * It is possible to switch AioContexts using
+ * vhost_user_server_detach_aio_context() and
+ * vhost_user_server_attach_aio_context(). They stop monitoring fds in the old
+ * AioContext and resume monitoring in the new AioContext. The vu_client_trip()
+ * coroutine remains in a yielded state during the switch. This is made
+ * possible by QIOChannel's support for spurious coroutine re-entry in
+ * qio_channel_yield(). The coroutine will restart I/O when re-entered from the
+ * new AioContext.
+ */
+
 static void vmsg_close_fds(VhostUserMsg *vmsg)
 {
     int i;
@@ -XXX,XX +XXX,XX @@ static void vmsg_unblock_fds(VhostUserMsg *vmsg)
     }
 }
 
-static void vu_accept(QIONetListener *listener, QIOChannelSocket *sioc,
-                      gpointer opaque);
-
-static void close_client(VuServer *server)
-{
-    /*
-     * Before closing the client
-     *
-     * 1. Let vu_client_trip stop processing new vhost-user msg
-     *
-     * 2. remove kick_handler
-     *
-     * 3. wait for the kick handler to be finished
-     *
-     * 4. wait for the current vhost-user msg to be finished processing
-     */
-
-    QIOChannelSocket *sioc = server->sioc;
-    /* When this is set vu_client_trip will stop new processing vhost-user message */
-    server->sioc = NULL;
-
-    while (server->processing_msg) {
-        if (server->ioc->read_coroutine) {
-            server->ioc->read_coroutine = NULL;
-            qio_channel_set_aio_fd_handler(server->ioc, server->ioc->ctx, NULL,
-                                           NULL, server->ioc);
-            server->processing_msg = false;
-        }
-    }
-
-    vu_deinit(&server->vu_dev);
-
-    /* vu_deinit() should have called remove_watch() */
-    assert(QTAILQ_EMPTY(&server->vu_fd_watches));
-
-    object_unref(OBJECT(sioc));
-    object_unref(OBJECT(server->ioc));
-}
-
 static void panic_cb(VuDev *vu_dev, const char *buf)
 {
-    VuServer *server = container_of(vu_dev, VuServer, vu_dev);
-
-    /* avoid while loop in close_client */
-    server->processing_msg = false;
-
-    if (buf) {
-        error_report("vu_panic: %s", buf);
-    }
-
-    if (server->sioc) {
-        close_client(server);
-    }
-
-    /*
-     * Set the callback function for network listener so another
-     * vhost-user client can connect to this server
-     */
-    qio_net_listener_set_client_func(server->listener,
-                                     vu_accept,
-                                     server,
-                                     NULL);
+    error_report("vu_panic: %s", buf);
 }
 
 static bool coroutine_fn
@@ -XXX,XX +XXX,XX @@ fail:
     return false;
 }
 
-
-static void vu_client_start(VuServer *server);
 static coroutine_fn void vu_client_trip(void *opaque)
 {
     VuServer *server = opaque;
+    VuDev *vu_dev = &server->vu_dev;
 
-    while (!server->aio_context_changed && server->sioc) {
-        server->processing_msg = true;
-        vu_dispatch(&server->vu_dev);
-        server->processing_msg = false;
+    while (!vu_dev->broken && vu_dispatch(vu_dev)) {
+        /* Keep running */
     }
 
-    if (server->aio_context_changed && server->sioc) {
-        server->aio_context_changed = false;
-        vu_client_start(server);
-    }
-}
+    vu_deinit(vu_dev);
+
+    /* vu_deinit() should have called remove_watch() */
+    assert(QTAILQ_EMPTY(&server->vu_fd_watches));
+
+    object_unref(OBJECT(server->sioc));
+    server->sioc = NULL;
 
-static void vu_client_start(VuServer *server)
-{
-    server->co_trip = qemu_coroutine_create(vu_client_trip, server);
-    aio_co_enter(server->ctx, server->co_trip);
+    object_unref(OBJECT(server->ioc));
+    server->ioc = NULL;
+
+    server->co_trip = NULL;
+    if (server->restart_listener_bh) {
+        qemu_bh_schedule(server->restart_listener_bh);
+    }
+    aio_wait_kick();
 }
 
 /*
@@ -XXX,XX +XXX,XX @@ static void vu_client_start(VuServer *server)
 static void kick_handler(void *opaque)
 {
     VuFdWatch *vu_fd_watch = opaque;
-    vu_fd_watch->processing = true;
-    vu_fd_watch->cb(vu_fd_watch->vu_dev, 0, vu_fd_watch->pvt);
-    vu_fd_watch->processing = false;
+    VuDev *vu_dev = vu_fd_watch->vu_dev;
+
+    vu_fd_watch->cb(vu_dev, 0, vu_fd_watch->pvt);
+
+    /* Stop vu_client_trip() if an error occurred in vu_fd_watch->cb() */
+    if (vu_dev->broken) {
+        VuServer *server = container_of(vu_dev, VuServer, vu_dev);
+
+        qio_channel_shutdown(server->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+    }
 }
 
-
 static VuFdWatch *find_vu_fd_watch(VuServer *server, int fd)
 {
 
@@ -XXX,XX +XXX,XX @@ static void vu_accept(QIONetListener *listener, QIOChannelSocket *sioc,
     qio_channel_set_name(QIO_CHANNEL(sioc), "vhost-user client");
     server->ioc = QIO_CHANNEL(sioc);
     object_ref(OBJECT(server->ioc));
-    qio_channel_attach_aio_context(server->ioc, server->ctx);
+
+    /* TODO vu_message_write() spins if non-blocking! */
     qio_channel_set_blocking(server->ioc, false, NULL);
-    vu_client_start(server);
+
+    server->co_trip = qemu_coroutine_create(vu_client_trip, server);
+
+    aio_context_acquire(server->ctx);
+    vhost_user_server_attach_aio_context(server, server->ctx);
+    aio_context_release(server->ctx);
 }
 
-
 void vhost_user_server_stop(VuServer *server)
 {
+    aio_context_acquire(server->ctx);
+
+    qemu_bh_delete(server->restart_listener_bh);
+    server->restart_listener_bh = NULL;
+
     if (server->sioc) {
-        close_client(server);
+        VuFdWatch *vu_fd_watch;
+
+        QTAILQ_FOREACH(vu_fd_watch, &server->vu_fd_watches, next) {
+            aio_set_fd_handler(server->ctx, vu_fd_watch->fd, true,
+                               NULL, NULL, NULL, vu_fd_watch);
+        }
+
+        qio_channel_shutdown(server->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+
+        AIO_WAIT_WHILE(server->ctx, server->co_trip);
     }
 
+    aio_context_release(server->ctx);
+
     if (server->listener) {
         qio_net_listener_disconnect(server->listener);
         object_unref(OBJECT(server->listener));
     }
+}
+
+/*
+ * Allow the next client to connect to the server. Called from a BH in the main
+ * loop.
+ */
+static void restart_listener_bh(void *opaque)
+{
+    VuServer *server = opaque;
 
+    qio_net_listener_set_client_func(server->listener, vu_accept, server,
+                                     NULL);
 }
 
-void vhost_user_server_set_aio_context(VuServer *server, AioContext *ctx)
+/* Called with ctx acquired */
+void vhost_user_server_attach_aio_context(VuServer *server, AioContext *ctx)
 {
-    VuFdWatch *vu_fd_watch, *next;
-    void *opaque = NULL;
-    IOHandler *io_read = NULL;
-    bool attach;
+    VuFdWatch *vu_fd_watch;
 
-    server->ctx = ctx ? ctx : qemu_get_aio_context();
+    server->ctx = ctx;
 
     if (!server->sioc) {
-        /* not yet serving any client*/
         return;
     }
 
-    if (ctx) {
-        qio_channel_attach_aio_context(server->ioc, ctx);
-        server->aio_context_changed = true;
-        io_read = kick_handler;
-        attach = true;
-    } else {
+    qio_channel_attach_aio_context(server->ioc, ctx);
+
+    QTAILQ_FOREACH(vu_fd_watch, &server->vu_fd_watches, next) {
+        aio_set_fd_handler(ctx, vu_fd_watch->fd, true, kick_handler, NULL,
+                           NULL, vu_fd_watch);
+    }
+
+    aio_co_schedule(ctx, server->co_trip);
+}
+
+/* Called with server->ctx acquired */
+void vhost_user_server_detach_aio_context(VuServer *server)
+{
+    if (server->sioc) {
+        VuFdWatch *vu_fd_watch;
+
+        QTAILQ_FOREACH(vu_fd_watch, &server->vu_fd_watches, next) {
+            aio_set_fd_handler(server->ctx, vu_fd_watch->fd, true,
+                               NULL, NULL, NULL, vu_fd_watch);
+        }
+
         qio_channel_detach_aio_context(server->ioc);
-        /* server->ioc->ctx keeps the old AioConext */
-        ctx = server->ioc->ctx;
-        attach = false;
     }
 
-    QTAILQ_FOREACH_SAFE(vu_fd_watch, &server->vu_fd_watches, next, next) {
-        if (vu_fd_watch->cb) {
-            opaque = attach ? vu_fd_watch : NULL;
-            aio_set_fd_handler(ctx, vu_fd_watch->fd, true,
-                               io_read, NULL, NULL,
-                               opaque);
-        }
-    }
+    server->ctx = NULL;
 }
 
-
 bool vhost_user_server_start(VuServer *server,
                              SocketAddress *socket_addr,
                              AioContext *ctx,
@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
                              const VuDevIface *vu_iface,
                              Error **errp)
 {
+    QEMUBH *bh;
     QIONetListener *listener = qio_net_listener_new();
     if (qio_net_listener_open_sync(listener, socket_addr, 1,
                                    errp) < 0) {
@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
         return false;
     }
 
+    bh = qemu_bh_new(restart_listener_bh, server);
+
     /* zero out unspecified fields */
     *server = (VuServer) {
         .listener              = listener,
+        .restart_listener_bh   = bh,
         .vu_iface              = vu_iface,
         .max_queues            = max_queues,
         .ctx                   = ctx,
-- 
2.26.2

Propagate the flush return value since errors are possible.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-11-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/export/vhost-user-blk-server.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

Use the new QAPI block exports API instead of defining our own QOM
objects.

This is a large change because the lifecycle of VuBlockDev needs to
follow BlockExportDriver. QOM properties are replaced by QAPI options
objects.

VuBlockDev is renamed VuBlkExport and contains a BlockExport field.
Several fields can be dropped since BlockExport already has equivalents.

The file names and meson build integration will be adjusted in a future
patch. libvhost-user should probably be built as a static library that
is linked into QEMU instead of as a .c file that results in duplicate
compilation.

The new command-line syntax is:

$ qemu-storage-daemon \
      --blockdev file,node-name=drive0,filename=test.img \
      --export vhost-user-blk,node-name=drive0,id=export0,unix-socket=/tmp/vhost-user-blk.sock

Note that unix-socket is optional because we may wish to accept chardevs
too in the future.

Markus noted that supported address families are not explicit in the
QAPI schema. It is unlikely that support for more address families will
be added since file descriptor passing is required and few address
families support it. If a new address family needs to be added, then the
QAPI 'features' syntax can be used to advertize them.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20200924151549.913737-12-stefanha@redhat.com
[Skip test on big-endian host architectures because this device doesn't
support them yet (as already mentioned in a code comment).
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qapi/block-export.json               |  21 +-
 block/export/vhost-user-blk-server.h |  23 +-
 block/export/export.c                |   6 +
 block/export/vhost-user-blk-server.c | 452 +++++++--------------------
 util/vhost-user-server.c             |  10 +-
 block/export/meson.build             |   1 +
 block/meson.build                    |   1 -
 7 files changed, 156 insertions(+), 358 deletions(-)

diff --git a/qapi/block-export.json b/qapi/block-export.json
index XXXXXXX..XXXXXXX 100644
--- a/qapi/block-export.json
+++ b/qapi/block-export.json
@@ -XXX,XX +XXX,XX @@
   'data': { '*name': 'str', '*description': 'str',
             '*bitmap': 'str' } }
 
+##
+# @BlockExportOptionsVhostUserBlk:
+#
+# A vhost-user-blk block export.
+#
+# @addr: The vhost-user socket on which to listen. Both 'unix' and 'fd'
+#        SocketAddress types are supported. Passed fds must be UNIX domain
+#        sockets.
+# @logical-block-size: Logical block size in bytes. Defaults to 512 bytes.
+#
+# Since: 5.2
+##
+{ 'struct': 'BlockExportOptionsVhostUserBlk',
+  'data': { 'addr': 'SocketAddress', '*logical-block-size': 'size' } }
+
 ##
 # @NbdServerAddOptions:
 #
@@ -XXX,XX +XXX,XX @@
 # An enumeration of block export types
 #
 # @nbd: NBD export
+# @vhost-user-blk: vhost-user-blk export (since 5.2)
 #
 # Since: 4.2
 ##
 { 'enum': 'BlockExportType',
-  'data': [ 'nbd' ] }
+  'data': [ 'nbd', 'vhost-user-blk' ] }
 
 ##
 # @BlockExportOptions:
@@ -XXX,XX +XXX,XX @@
             '*writethrough': 'bool' },
   'discriminator': 'type',
   'data': {
-      'nbd': 'BlockExportOptionsNbd'
+      'nbd': 'BlockExportOptionsNbd',
+      'vhost-user-blk': 'BlockExportOptionsVhostUserBlk'
    } }
 
 ##
diff --git a/block/export/vhost-user-blk-server.h b/block/export/vhost-user-blk-server.h
index XXXXXXX..XXXXXXX 100644
--- a/block/export/vhost-user-blk-server.h
+++ b/block/export/vhost-user-blk-server.h
@@ -XXX,XX +XXX,XX @@
 
 #ifndef VHOST_USER_BLK_SERVER_H
 #define VHOST_USER_BLK_SERVER_H
-#include "util/vhost-user-server.h"
 
-typedef struct VuBlockDev VuBlockDev;
-#define TYPE_VHOST_USER_BLK_SERVER "vhost-user-blk-server"
-#define VHOST_USER_BLK_SERVER(obj) \
-   OBJECT_CHECK(VuBlockDev, obj, TYPE_VHOST_USER_BLK_SERVER)
+#include "block/export.h"
 
-/* vhost user block device */
-struct VuBlockDev {
-    Object parent_obj;
-    char *node_name;
-    SocketAddress *addr;
-    AioContext *ctx;
-    VuServer vu_server;
-    bool running;
-    uint32_t blk_size;
-    BlockBackend *backend;
-    QIOChannelSocket *sioc;
-    QTAILQ_ENTRY(VuBlockDev) next;
-    struct virtio_blk_config blkcfg;
-    bool writable;
-};
+/* For block/export/export.c */
+extern const BlockExportDriver blk_exp_vhost_user_blk;
 
 #endif /* VHOST_USER_BLK_SERVER_H */
diff --git a/block/export/export.c b/block/export/export.c
index XXXXXXX..XXXXXXX 100644
--- a/block/export/export.c
+++ b/block/export/export.c
@@ -XXX,XX +XXX,XX @@
 #include "sysemu/block-backend.h"
 #include "block/export.h"
 #include "block/nbd.h"
+#if CONFIG_LINUX
+#include "block/export/vhost-user-blk-server.h"
+#endif
 #include "qapi/error.h"
 #include "qapi/qapi-commands-block-export.h"
 #include "qapi/qapi-events-block-export.h"
@@ -XXX,XX +XXX,XX @@
 
 static const BlockExportDriver *blk_exp_drivers[] = {
     &blk_exp_nbd,
+#if CONFIG_LINUX
+    &blk_exp_vhost_user_blk,
+#endif
 };
 
 /* Only accessed from the main thread */
diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
index XXXXXXX..XXXXXXX 100644
--- a/block/export/vhost-user-blk-server.c
+++ b/block/export/vhost-user-blk-server.c
@@ -XXX,XX +XXX,XX @@
  */
 #include "qemu/osdep.h"
 #include "block/block.h"
+#include "contrib/libvhost-user/libvhost-user.h"
+#include "standard-headers/linux/virtio_blk.h"
+#include "util/vhost-user-server.h"
 #include "vhost-user-blk-server.h"
 #include "qapi/error.h"
 #include "qom/object_interfaces.h"
@@ -XXX,XX +XXX,XX @@ struct virtio_blk_inhdr {
     unsigned char status;
 };
 
-typedef struct VuBlockReq {
+typedef struct VuBlkReq {
     VuVirtqElement elem;
     int64_t sector_num;
     size_t size;
@@ -XXX,XX +XXX,XX @@ typedef struct VuBlockReq {
     struct virtio_blk_outhdr out;
     VuServer *server;
     struct VuVirtq *vq;
-} VuBlockReq;
+} VuBlkReq;
 
-static void vu_block_req_complete(VuBlockReq *req)
+/* vhost user block device */
+typedef struct {
+    BlockExport export;
+    VuServer vu_server;
+    uint32_t blk_size;
+    QIOChannelSocket *sioc;
+    struct virtio_blk_config blkcfg;
+    bool writable;
+} VuBlkExport;
+
+static void vu_blk_req_complete(VuBlkReq *req)
 {
     VuDev *vu_dev = &req->server->vu_dev;
 
@@ -XXX,XX +XXX,XX @@ static void vu_block_req_complete(VuBlockReq *req)
     free(req);
 }
 
-static VuBlockDev *get_vu_block_device_by_server(VuServer *server)
-{
-    return container_of(server, VuBlockDev, vu_server);
-}
-
 static int coroutine_fn
-vu_block_discard_write_zeroes(VuBlockReq *req, struct iovec *iov,
-                              uint32_t iovcnt, uint32_t type)
+vu_blk_discard_write_zeroes(BlockBackend *blk, struct iovec *iov,
+                            uint32_t iovcnt, uint32_t type)
 {
     struct virtio_blk_discard_write_zeroes desc;
     ssize_t size = iov_to_buf(iov, iovcnt, 0, &desc, sizeof(desc));
@@ -XXX,XX +XXX,XX @@ vu_block_discard_write_zeroes(VuBlockReq *req, struct iovec *iov,
         return -EINVAL;
     }
 
-    VuBlockDev *vdev_blk = get_vu_block_device_by_server(req->server);
     uint64_t range[2] = { le64_to_cpu(desc.sector) << 9,
                           le32_to_cpu(desc.num_sectors) << 9 };
     if (type == VIRTIO_BLK_T_DISCARD) {
-        if (blk_co_pdiscard(vdev_blk->backend, range[0], range[1]) == 0) {
+        if (blk_co_pdiscard(blk, range[0], range[1]) == 0) {
             return 0;
         }
     } else if (type == VIRTIO_BLK_T_WRITE_ZEROES) {
-        if (blk_co_pwrite_zeroes(vdev_blk->backend,
-                                 range[0], range[1], 0) == 0) {
+        if (blk_co_pwrite_zeroes(blk, range[0], range[1], 0) == 0) {
             return 0;
         }
     }
@@ -XXX,XX +XXX,XX @@ vu_block_discard_write_zeroes(VuBlockReq *req, struct iovec *iov,
     return -EINVAL;
 }
 
-static int coroutine_fn vu_block_flush(VuBlockReq *req)
+static void coroutine_fn vu_blk_virtio_process_req(void *opaque)
 {
-    VuBlockDev *vdev_blk = get_vu_block_device_by_server(req->server);
-    BlockBackend *backend = vdev_blk->backend;
-    return blk_co_flush(backend);
-}
-
-static void coroutine_fn vu_block_virtio_process_req(void *opaque)
-{
-    VuBlockReq *req = opaque;
+    VuBlkReq *req = opaque;
     VuServer *server = req->server;
     VuVirtqElement *elem = &req->elem;
     uint32_t type;
 
-    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
-    BlockBackend *backend = vdev_blk->backend;
+    VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server);
+    BlockBackend *blk = vexp->export.blk;
 
     struct iovec *in_iov = elem->in_sg;
     struct iovec *out_iov = elem->out_sg;
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
         bool is_write = type & VIRTIO_BLK_T_OUT;
         req->sector_num = le64_to_cpu(req->out.sector);
 
-        int64_t offset = req->sector_num * vdev_blk->blk_size;
+        if (is_write && !vexp->writable) {
+            req->in->status = VIRTIO_BLK_S_IOERR;
+            break;
+        }
+
+        int64_t offset = req->sector_num * vexp->blk_size;
         QEMUIOVector qiov;
         if (is_write) {
             qemu_iovec_init_external(&qiov, out_iov, out_num);
-            ret = blk_co_pwritev(backend, offset, qiov.size,
-                                 &qiov, 0);
+            ret = blk_co_pwritev(blk, offset, qiov.size, &qiov, 0);
         } else {
             qemu_iovec_init_external(&qiov, in_iov, in_num);
-            ret = blk_co_preadv(backend, offset, qiov.size,
-                                &qiov, 0);
+            ret = blk_co_preadv(blk, offset, qiov.size, &qiov, 0);
         }
         if (ret >= 0) {
             req->in->status = VIRTIO_BLK_S_OK;
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
         break;
     }
     case VIRTIO_BLK_T_FLUSH:
-        if (vu_block_flush(req) == 0) {
+        if (blk_co_flush(blk) == 0) {
             req->in->status = VIRTIO_BLK_S_OK;
         } else {
             req->in->status = VIRTIO_BLK_S_IOERR;
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
     case VIRTIO_BLK_T_DISCARD:
     case VIRTIO_BLK_T_WRITE_ZEROES: {
         int rc;
-        rc = vu_block_discard_write_zeroes(req, &elem->out_sg[1],
-                                           out_num, type);
+
+        if (!vexp->writable) {
+            req->in->status = VIRTIO_BLK_S_IOERR;
+            break;
+        }
+
+        rc = vu_blk_discard_write_zeroes(blk, &elem->out_sg[1], out_num, type);
         if (rc == 0) {
             req->in->status = VIRTIO_BLK_S_OK;
         } else {
@@ -XXX,XX +XXX,XX @@ static void coroutine_fn vu_block_virtio_process_req(void *opaque)
         break;
     }
 
-    vu_block_req_complete(req);
+    vu_blk_req_complete(req);
     return;
 
 err:
-    free(elem);
+    free(req);
 }
 
-static void vu_block_process_vq(VuDev *vu_dev, int idx)
+static void vu_blk_process_vq(VuDev *vu_dev, int idx)
 {
     VuServer *server = container_of(vu_dev, VuServer, vu_dev);
     VuVirtq *vq = vu_get_queue(vu_dev, idx);
 
     while (1) {
-        VuBlockReq *req;
+        VuBlkReq *req;
 
-        req = vu_queue_pop(vu_dev, vq, sizeof(VuBlockReq));
+        req = vu_queue_pop(vu_dev, vq, sizeof(VuBlkReq));
         if (!req) {
             break;
         }
@@ -XXX,XX +XXX,XX @@ static void vu_block_process_vq(VuDev *vu_dev, int idx)
         req->vq = vq;
 
         Coroutine *co =
-            qemu_coroutine_create(vu_block_virtio_process_req, req);
+            qemu_coroutine_create(vu_blk_virtio_process_req, req);
         qemu_coroutine_enter(co);
     }
 }
 
-static void vu_block_queue_set_started(VuDev *vu_dev, int idx, bool started)
+static void vu_blk_queue_set_started(VuDev *vu_dev, int idx, bool started)
 {
     VuVirtq *vq;
 
     assert(vu_dev);
 
     vq = vu_get_queue(vu_dev, idx);
-    vu_set_queue_handler(vu_dev, vq, started ? vu_block_process_vq : NULL);
+    vu_set_queue_handler(vu_dev, vq, started ? vu_blk_process_vq : NULL);
 }
 
-static uint64_t vu_block_get_features(VuDev *dev)
+static uint64_t vu_blk_get_features(VuDev *dev)
 {
     uint64_t features;
     VuServer *server = container_of(dev, VuServer, vu_dev);
-    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
+    VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server);
     features = 1ull << VIRTIO_BLK_F_SIZE_MAX |
                1ull << VIRTIO_BLK_F_SEG_MAX |
                1ull << VIRTIO_BLK_F_TOPOLOGY |
@@ -XXX,XX +XXX,XX @@ static uint64_t vu_block_get_features(VuDev *dev)
                1ull << VIRTIO_RING_F_EVENT_IDX |
                1ull << VHOST_USER_F_PROTOCOL_FEATURES;
 
-    if (!vdev_blk->writable) {
+    if (!vexp->writable) {
         features |= 1ull << VIRTIO_BLK_F_RO;
     }
 
     return features;
 }
 
-static uint64_t vu_block_get_protocol_features(VuDev *dev)
+static uint64_t vu_blk_get_protocol_features(VuDev *dev)
 {
     return 1ull << VHOST_USER_PROTOCOL_F_CONFIG |
            1ull << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD;
 }
 
 static int
-vu_block_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
+vu_blk_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
 {
+    /* TODO blkcfg must be little-endian for VIRTIO 1.0 */
     VuServer *server = container_of(vu_dev, VuServer, vu_dev);
-    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
-    memcpy(config, &vdev_blk->blkcfg, len);
-
+    VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server);
+    memcpy(config, &vexp->blkcfg, len);
     return 0;
 }
 
 static int
-vu_block_set_config(VuDev *vu_dev, const uint8_t *data,
+vu_blk_set_config(VuDev *vu_dev, const uint8_t *data,
                     uint32_t offset, uint32_t size, uint32_t flags)
 {
     VuServer *server = container_of(vu_dev, VuServer, vu_dev);
-    VuBlockDev *vdev_blk = get_vu_block_device_by_server(server);
+    VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server);
     uint8_t wce;
 
     /* don't support live migration */
@@ -XXX,XX +XXX,XX @@ vu_block_set_config(VuDev *vu_dev, const uint8_t *data,
     }
 
     wce = *data;
-    vdev_blk->blkcfg.wce = wce;
-    blk_set_enable_write_cache(vdev_blk->backend, wce);
+    vexp->blkcfg.wce = wce;
+    blk_set_enable_write_cache(vexp->export.blk, wce);
     return 0;
 }
 
@@ -XXX,XX +XXX,XX @@ vu_block_set_config(VuDev *vu_dev, const uint8_t *data,
  * of vu_process_message.
  *
  */
-static int vu_block_process_msg(VuDev *dev, VhostUserMsg *vmsg, int *do_reply)
+static int vu_blk_process_msg(VuDev *dev, VhostUserMsg *vmsg, int *do_reply)
 {
     if (vmsg->request == VHOST_USER_NONE) {
         dev->panic(dev, "disconnect");
@@ -XXX,XX +XXX,XX @@ static int vu_block_process_msg(VuDev *dev, VhostUserMsg *vmsg, int *do_reply)
     return false;
 }
 
-static const VuDevIface vu_block_iface = {
-    .get_features          = vu_block_get_features,
-    .queue_set_started     = vu_block_queue_set_started,
-    .get_protocol_features = vu_block_get_protocol_features,
-    .get_config            = vu_block_get_config,
-    .set_config            = vu_block_set_config,
-    .process_msg           = vu_block_process_msg,
+static const VuDevIface vu_blk_iface = {
+    .get_features          = vu_blk_get_features,
+    .queue_set_started     = vu_blk_queue_set_started,
+    .get_protocol_features = vu_blk_get_protocol_features,
+    .get_config            = vu_blk_get_config,
+    .set_config            = vu_blk_set_config,
+    .process_msg           = vu_blk_process_msg,
 };
 
 static void blk_aio_attached(AioContext *ctx, void *opaque)
 {
-    VuBlockDev *vub_dev = opaque;
-    vhost_user_server_attach_aio_context(&vub_dev->vu_server, ctx);
+    VuBlkExport *vexp = opaque;
+    vhost_user_server_attach_aio_context(&vexp->vu_server, ctx);
 }
 
 static void blk_aio_detach(void *opaque)
 {
-    VuBlockDev *vub_dev = opaque;
-    vhost_user_server_detach_aio_context(&vub_dev->vu_server);
+    VuBlkExport *vexp = opaque;
+    vhost_user_server_detach_aio_context(&vexp->vu_server);
 }
 
 static void
-vu_block_initialize_config(BlockDriverState *bs,
+vu_blk_initialize_config(BlockDriverState *bs,
                            struct virtio_blk_config *config, uint32_t blk_size)
 {
     config->capacity = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
@@ -XXX,XX +XXX,XX @@ vu_block_initialize_config(BlockDriverState *bs,
     config->max_write_zeroes_seg = 1;
 }
 
-static VuBlockDev *vu_block_init(VuBlockDev *vu_block_device, Error **errp)
+static void vu_blk_exp_request_shutdown(BlockExport *exp)
 {
+    VuBlkExport *vexp = container_of(exp, VuBlkExport, export);
 
-    BlockBackend *blk;
-    Error *local_error = NULL;
-    const char *node_name = vu_block_device->node_name;
-    bool writable = vu_block_device->writable;
-    uint64_t perm = BLK_PERM_CONSISTENT_READ;
-    int ret;
-
-    AioContext *ctx;
-
-    BlockDriverState *bs = bdrv_lookup_bs(node_name, node_name, &local_error);
-
-    if (!bs) {
-        error_propagate(errp, local_error);
-        return NULL;
-    }
-
-    if (bdrv_is_read_only(bs)) {
-        writable = false;
-    }
-
-    if (writable) {
-        perm |= BLK_PERM_WRITE;
-    }
-
-    ctx = bdrv_get_aio_context(bs);
-    aio_context_acquire(ctx);
-    bdrv_invalidate_cache(bs, NULL);
-    aio_context_release(ctx);
-
-    /*
-     * Don't allow resize while the vhost user server is running,
-     * otherwise we don't care what happens with the node.
-     */
-    blk = blk_new(bdrv_get_aio_context(bs), perm,
-                  BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
-                  BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD);
-    ret = blk_insert_bs(blk, bs, errp);
-
-    if (ret < 0) {
-        goto fail;
-    }
-
-    blk_set_enable_write_cache(blk, false);
-
-    blk_set_allow_aio_context_change(blk, true);
-
-    vu_block_device->blkcfg.wce = 0;
-    vu_block_device->backend = blk;
-    if (!vu_block_device->blk_size) {
-        vu_block_device->blk_size = BDRV_SECTOR_SIZE;
-    }
-    vu_block_device->blkcfg.blk_size = vu_block_device->blk_size;
-    blk_set_guest_block_size(blk, vu_block_device->blk_size);
-    vu_block_initialize_config(bs, &vu_block_device->blkcfg,
-                                   vu_block_device->blk_size);
-    return vu_block_device;
-
-fail:
-    blk_unref(blk);
-    return NULL;
-}
-
-static void vu_block_deinit(VuBlockDev *vu_block_device)
-{
-    if (vu_block_device->backend) {
-        blk_remove_aio_context_notifier(vu_block_device->backend, blk_aio_attached,
-                                        blk_aio_detach, vu_block_device);
-    }
-
-    blk_unref(vu_block_device->backend);
-}
-
-static void vhost_user_blk_server_stop(VuBlockDev *vu_block_device)
-{
-    vhost_user_server_stop(&vu_block_device->vu_server);
-    vu_block_deinit(vu_block_device);
-}
-
-static void vhost_user_blk_server_start(VuBlockDev *vu_block_device,
-                                        Error **errp)
-{
-    AioContext *ctx;
-    SocketAddress *addr = vu_block_device->addr;
-
-    if (!vu_block_init(vu_block_device, errp)) {
-        return;
-    }
-
-    ctx = bdrv_get_aio_context(blk_bs(vu_block_device->backend));
-
-    if (!vhost_user_server_start(&vu_block_device->vu_server, addr, ctx,
-                                 VHOST_USER_BLK_MAX_QUEUES, &vu_block_iface,
-                                 errp)) {
-        goto error;
-    }
-
-    blk_add_aio_context_notifier(vu_block_device->backend, blk_aio_attached,
-                                 blk_aio_detach, vu_block_device);
-    vu_block_device->running = true;
-    return;
-
- error:
-    vu_block_deinit(vu_block_device);
-}
-
-static bool vu_prop_modifiable(VuBlockDev *vus, Error **errp)
-{
-    if (vus->running) {
-            error_setg(errp, "The property can't be modified "
-                       "while the server is running");
-            return false;
-    }
-    return true;
-}
-
-static void vu_set_node_name(Object *obj, const char *value, Error **errp)
-{
-    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
-
-    if (!vu_prop_modifiable(vus, errp)) {
-        return;
-    }
-
-    if (vus->node_name) {
-        g_free(vus->node_name);
-    }
-
-    vus->node_name = g_strdup(value);
-}
-
-static char *vu_get_node_name(Object *obj, Error **errp)
-{
-    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
-    return g_strdup(vus->node_name);
-}
-
-static void free_socket_addr(SocketAddress *addr)
-{
-        g_free(addr->u.q_unix.path);
-        g_free(addr);
-}
-
-static void vu_set_unix_socket(Object *obj, const char *value,
-                               Error **errp)
-{
-    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
-
-    if (!vu_prop_modifiable(vus, errp)) {
-        return;
-    }
-
-    if (vus->addr) {
-        free_socket_addr(vus->addr);
-    }
-
-    SocketAddress *addr = g_new0(SocketAddress, 1);
-    addr->type = SOCKET_ADDRESS_TYPE_UNIX;
-    addr->u.q_unix.path = g_strdup(value);
-    vus->addr = addr;
+    vhost_user_server_stop(&vexp->vu_server);
 }
 
-static char *vu_get_unix_socket(Object *obj, Error **errp)
+static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
+                             Error **errp)
 {
-    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
-    return g_strdup(vus->addr->u.q_unix.path);
-}
-
-static bool vu_get_block_writable(Object *obj, Error **errp)
-{
-    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
-    return vus->writable;
-}
-
-static void vu_set_block_writable(Object *obj, bool value, Error **errp)
-{
-    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
-
-    if (!vu_prop_modifiable(vus, errp)) {
-            return;
-    }
-
-    vus->writable = value;
-}
-
-static void vu_get_blk_size(Object *obj, Visitor *v, const char *name,
-                            void *opaque, Error **errp)
-{
-    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
-    uint32_t value = vus->blk_size;
-
-    visit_type_uint32(v, name, &value, errp);
-}
-
-static void vu_set_blk_size(Object *obj, Visitor *v, const char *name,
-                            void *opaque, Error **errp)
-{
-    VuBlockDev *vus = VHOST_USER_BLK_SERVER(obj);
-
+    VuBlkExport *vexp = container_of(exp, VuBlkExport, export);
+    BlockExportOptionsVhostUserBlk *vu_opts = &opts->u.vhost_user_blk;
     Error *local_err = NULL;
-    uint32_t value;
+    uint64_t logical_block_size;
 
-    if (!vu_prop_modifiable(vus, errp)) {
-            return;
-    }
+    vexp->writable = opts->writable;
+    vexp->blkcfg.wce = 0;
 
-    visit_type_uint32(v, name, &value, &local_err);
-    if (local_err) {
-        goto out;
+    if (vu_opts->has_logical_block_size) {
+        logical_block_size = vu_opts->logical_block_size;
+    } else {
+        logical_block_size = BDRV_SECTOR_SIZE;
     }
-
-    check_block_size(object_get_typename(obj), name, value, &local_err);
+    check_block_size(exp->id, "logical-block-size", logical_block_size,
+                     &local_err);
     if (local_err) {
-        goto out;
+        error_propagate(errp, local_err);
+        return -EINVAL;
+    }
+    vexp->blk_size = logical_block_size;
+    blk_set_guest_block_size(exp->blk, logical_block_size);
+    vu_blk_initialize_config(blk_bs(exp->blk), &vexp->blkcfg,
+                               logical_block_size);
+
+    blk_set_allow_aio_context_change(exp->blk, true);
+    blk_add_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
+                                 vexp);
+
+    if (!vhost_user_server_start(&vexp->vu_server, vu_opts->addr, exp->ctx,
+                                 VHOST_USER_BLK_MAX_QUEUES, &vu_blk_iface,
+                                 errp)) {
+        blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
+                                        blk_aio_detach, vexp);
+        return -EADDRNOTAVAIL;
     }
 
-    vus->blk_size = value;
-
-out:
-    error_propagate(errp, local_err);
-}
-
-static void vhost_user_blk_server_instance_finalize(Object *obj)
-{
-    VuBlockDev *vub = VHOST_USER_BLK_SERVER(obj);
-
-    vhost_user_blk_server_stop(vub);
-
-    /*
-     * Unlike object_property_add_str, object_class_property_add_str
-     * doesn't have a release method. Thus manual memory freeing is
-     * needed.
-     */
-    free_socket_addr(vub->addr);
-    g_free(vub->node_name);
-}
-
-static void vhost_user_blk_server_complete(UserCreatable *obj, Error **errp)
-{
-    VuBlockDev *vub = VHOST_USER_BLK_SERVER(obj);
-
-    vhost_user_blk_server_start(vub, errp);
+    return 0;
 }
 
-static void vhost_user_blk_server_class_init(ObjectClass *klass,
-                                             void *class_data)
+static void vu_blk_exp_delete(BlockExport *exp)
 {
-    UserCreatableClass *ucc = USER_CREATABLE_CLASS(klass);
-    ucc->complete = vhost_user_blk_server_complete;
-
-    object_class_property_add_bool(klass, "writable",
-                                   vu_get_block_writable,
-                                   vu_set_block_writable);
-
-    object_class_property_add_str(klass, "node-name",
-                                  vu_get_node_name,
-                                  vu_set_node_name);
-
-    object_class_property_add_str(klass, "unix-socket",
-                                  vu_get_unix_socket,
-                                  vu_set_unix_socket);
+    VuBlkExport *vexp = container_of(exp, VuBlkExport, export);
 
-    object_class_property_add(klass, "logical-block-size", "uint32",
-                              vu_get_blk_size, vu_set_blk_size,
-                              NULL, NULL);
+    blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
+                                    vexp);
 }
 
-static const TypeInfo vhost_user_blk_server_info = {
-    .name = TYPE_VHOST_USER_BLK_SERVER,
-    .parent = TYPE_OBJECT,
-    .instance_size = sizeof(VuBlockDev),
-    .instance_finalize = vhost_user_blk_server_instance_finalize,
-    .class_init = vhost_user_blk_server_class_init,
-    .interfaces = (InterfaceInfo[]) {
-        {TYPE_USER_CREATABLE},
-        {}
-    },
+const BlockExportDriver blk_exp_vhost_user_blk = {
+    .type               = BLOCK_EXPORT_TYPE_VHOST_USER_BLK,
+    .instance_size      = sizeof(VuBlkExport),
+    .create             = vu_blk_exp_create,
+    .delete             = vu_blk_exp_delete,
+    .request_shutdown   = vu_blk_exp_request_shutdown,
 };
-
-static void vhost_user_blk_server_register_types(void)
-{
-    type_register_static(&vhost_user_blk_server_info);
-}
-
-type_init(vhost_user_blk_server_register_types)
diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
index XXXXXXX..XXXXXXX 100644
--- a/util/vhost-user-server.c
+++ b/util/vhost-user-server.c
@@ -XXX,XX +XXX,XX @@ bool vhost_user_server_start(VuServer *server,
                              Error **errp)
 {
     QEMUBH *bh;
-    QIONetListener *listener = qio_net_listener_new();
+    QIONetListener *listener;
+
+    if (socket_addr->type != SOCKET_ADDRESS_TYPE_UNIX &&
+        socket_addr->type != SOCKET_ADDRESS_TYPE_FD) {
+        error_setg(errp, "Only socket address types 'unix' and 'fd' are supported");
+        return false;
+    }
+
+    listener = qio_net_listener_new();
     if (qio_net_listener_open_sync(listener, socket_addr, 1,
                                    errp) < 0) {
         object_unref(OBJECT(listener));
diff --git a/block/export/meson.build b/block/export/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/block/export/meson.build
+++ b/block/export/meson.build
@@ -1 +1,2 @@
 block_ss.add(files('export.c'))
+block_ss.add(when: 'CONFIG_LINUX', if_true: files('vhost-user-blk-server.c', '../../contrib/libvhost-user/libvhost-user.c'))
diff --git a/block/meson.build b/block/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/block/meson.build
+++ b/block/meson.build
@@ -XXX,XX +XXX,XX @@ block_ss.add(when: 'CONFIG_WIN32', if_true: files('file-win32.c', 'win32-aio.c')
 block_ss.add(when: 'CONFIG_POSIX', if_true: [files('file-posix.c'), coref, iokit])
 block_ss.add(when: 'CONFIG_LIBISCSI', if_true: files('iscsi-opts.c'))
 block_ss.add(when: 'CONFIG_LINUX', if_true: files('nvme.c'))
-block_ss.add(when: 'CONFIG_LINUX', if_true: files('export/vhost-user-blk-server.c', '../contrib/libvhost-user/libvhost-user.c'))
 block_ss.add(when: 'CONFIG_REPLICATION', if_true: files('replication.c'))
 block_ss.add(when: 'CONFIG_SHEEPDOG', if_true: files('sheepdog.c'))
 block_ss.add(when: ['CONFIG_LINUX_AIO', libaio], if_true: files('linux-aio.c'))
-- 
2.26.2

Headers used by other subsystems are located in include/. Also add the
vhost-user-server and vhost-user-blk-server headers to MAINTAINERS.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-13-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                                | 4 +++-
 {util => include/qemu}/vhost-user-server.h | 0
 block/export/vhost-user-blk-server.c       | 2 +-
 util/vhost-user-server.c                   | 2 +-
 4 files changed, 5 insertions(+), 3 deletions(-)
 rename {util => include/qemu}/vhost-user-server.h (100%)

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ Vhost-user block device backend server
 M: Coiby Xu <Coiby.Xu@gmail.com>
 S: Maintained
 F: block/export/vhost-user-blk-server.c
-F: util/vhost-user-server.c
+F: block/export/vhost-user-blk-server.h
+F: include/qemu/vhost-user-server.h
 F: tests/qtest/libqos/vhost-user-blk.c
+F: util/vhost-user-server.c
 
 Replication
 M: Wen Congyang <wencongyang2@huawei.com>
diff --git a/util/vhost-user-server.h b/include/qemu/vhost-user-server.h
similarity index 100%
rename from util/vhost-user-server.h
rename to include/qemu/vhost-user-server.h
diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
index XXXXXXX..XXXXXXX 100644
--- a/block/export/vhost-user-blk-server.c
+++ b/block/export/vhost-user-blk-server.c
@@ -XXX,XX +XXX,XX @@
 #include "block/block.h"
 #include "contrib/libvhost-user/libvhost-user.h"
 #include "standard-headers/linux/virtio_blk.h"
-#include "util/vhost-user-server.h"
+#include "qemu/vhost-user-server.h"
 #include "vhost-user-blk-server.h"
 #include "qapi/error.h"
 #include "qom/object_interfaces.h"
diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
index XXXXXXX..XXXXXXX 100644
--- a/util/vhost-user-server.c
+++ b/util/vhost-user-server.c
@@ -XXX,XX +XXX,XX @@
  */
 #include "qemu/osdep.h"
 #include "qemu/main-loop.h"
+#include "qemu/vhost-user-server.h"
 #include "block/aio-wait.h"
-#include "vhost-user-server.h"
 
 /*
  * Theory of operation:
-- 
2.26.2

Don't compile contrib/libvhost-user/libvhost-user.c again. Instead build
the static library once and then reuse it throughout QEMU.

Also switch from CONFIG_LINUX to CONFIG_VHOST_USER, which is what the
vhost-user tools (vhost-user-gpu, etc) do.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200924151549.913737-14-stefanha@redhat.com
[Added CONFIG_LINUX again because libvhost-user doesn't build on macOS.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/export/export.c             | 8 ++++----
 block/export/meson.build          | 2 +-
 contrib/libvhost-user/meson.build | 1 +
 meson.build                       | 6 +++++-
 util/meson.build                  | 4 +++-
 5 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/block/export/export.c b/block/export/export.c
index XXXXXXX..XXXXXXX 100644
--- a/block/export/export.c
+++ b/block/export/export.c
@@ -XXX,XX +XXX,XX @@
 #include "sysemu/block-backend.h"
 #include "block/export.h"
 #include "block/nbd.h"
-#if CONFIG_LINUX
-#include "block/export/vhost-user-blk-server.h"
-#endif
 #include "qapi/error.h"
 #include "qapi/qapi-commands-block-export.h"
 #include "qapi/qapi-events-block-export.h"
 #include "qemu/id.h"
+#ifdef CONFIG_VHOST_USER
+#include "vhost-user-blk-server.h"
+#endif
 
 static const BlockExportDriver *blk_exp_drivers[] = {
     &blk_exp_nbd,
-#if CONFIG_LINUX
+#ifdef CONFIG_VHOST_USER
     &blk_exp_vhost_user_blk,
 #endif
 };
diff --git a/block/export/meson.build b/block/export/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/block/export/meson.build
+++ b/block/export/meson.build
@@ -XXX,XX +XXX,XX @@
 block_ss.add(files('export.c'))
-block_ss.add(when: 'CONFIG_LINUX', if_true: files('vhost-user-blk-server.c', '../../contrib/libvhost-user/libvhost-user.c'))
+block_ss.add(when: ['CONFIG_LINUX', 'CONFIG_VHOST_USER'], if_true: files('vhost-user-blk-server.c'))
diff --git a/contrib/libvhost-user/meson.build b/contrib/libvhost-user/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/contrib/libvhost-user/meson.build
+++ b/contrib/libvhost-user/meson.build
@@ -XXX,XX +XXX,XX @@
 libvhost_user = static_library('vhost-user',
                                files('libvhost-user.c', 'libvhost-user-glib.c'),
                                build_by_default: false)
+vhost_user = declare_dependency(link_with: libvhost_user)
diff --git a/meson.build b/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/meson.build
+++ b/meson.build
@@ -XXX,XX +XXX,XX @@ trace_events_subdirs += [
   'util',
 ]
 
+vhost_user = not_found
+if 'CONFIG_VHOST_USER' in config_host
+  subdir('contrib/libvhost-user')
+endif
+
 subdir('qapi')
 subdir('qobject')
 subdir('stubs')
@@ -XXX,XX +XXX,XX @@ if have_tools
              install: true)
 
   if 'CONFIG_VHOST_USER' in config_host
-    subdir('contrib/libvhost-user')
     subdir('contrib/vhost-user-blk')
     subdir('contrib/vhost-user-gpu')
     subdir('contrib/vhost-user-input')
diff --git a/util/meson.build b/util/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/util/meson.build
+++ b/util/meson.build
@@ -XXX,XX +XXX,XX @@ if have_block
   util_ss.add(files('main-loop.c'))
   util_ss.add(files('nvdimm-utils.c'))
   util_ss.add(files('qemu-coroutine.c', 'qemu-coroutine-lock.c', 'qemu-coroutine-io.c'))
-  util_ss.add(when: 'CONFIG_LINUX', if_true: files('vhost-user-server.c'))
+  util_ss.add(when: ['CONFIG_LINUX', 'CONFIG_VHOST_USER'], if_true: [
+    files('vhost-user-server.c'), vhost_user
+  ])
   util_ss.add(files('block-helpers.c'))
   util_ss.add(files('qemu-coroutine-sleep.c'))
   util_ss.add(files('qemu-co-shared-resource.c'))
-- 
2.26.2

Introduce libblkdev.fa to avoid recompiling blockdev_ss twice.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200929125516.186715-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 meson.build                | 12 ++++++++++--
 storage-daemon/meson.build |  3 +--
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/meson.build b/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/meson.build
+++ b/meson.build
@@ -XXX,XX +XXX,XX @@ blockdev_ss.add(files(
 # os-win32.c does not
 blockdev_ss.add(when: 'CONFIG_POSIX', if_true: files('os-posix.c'))
 softmmu_ss.add(when: 'CONFIG_WIN32', if_true: [files('os-win32.c')])
-softmmu_ss.add_all(blockdev_ss)
 
 common_ss.add(files('cpus-common.c'))
 
@@ -XXX,XX +XXX,XX @@ block = declare_dependency(link_whole: [libblock],
                            link_args: '@block.syms',
                            dependencies: [crypto, io])
 
+blockdev_ss = blockdev_ss.apply(config_host, strict: false)
+libblockdev = static_library('blockdev', blockdev_ss.sources() + genh,
+                             dependencies: blockdev_ss.dependencies(),
+                             name_suffix: 'fa',
+                             build_by_default: false)
+
+blockdev = declare_dependency(link_whole: [libblockdev],
+                              dependencies: [block])
+
 qmp_ss = qmp_ss.apply(config_host, strict: false)
 libqmp = static_library('qmp', qmp_ss.sources() + genh,
                         dependencies: qmp_ss.dependencies(),
@@ -XXX,XX +XXX,XX @@ foreach m : block_mods + softmmu_mods
                 install_dir: config_host['qemu_moddir'])
 endforeach
 
-softmmu_ss.add(authz, block, chardev, crypto, io, qmp)
+softmmu_ss.add(authz, blockdev, chardev, crypto, io, qmp)
 common_ss.add(qom, qemuutil)
 
 common_ss.add_all(when: 'CONFIG_SOFTMMU', if_true: [softmmu_ss])
diff --git a/storage-daemon/meson.build b/storage-daemon/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/storage-daemon/meson.build
+++ b/storage-daemon/meson.build
@@ -XXX,XX +XXX,XX @@
 qsd_ss = ss.source_set()
 qsd_ss.add(files('qemu-storage-daemon.c'))
-qsd_ss.add(block, chardev, qmp, qom, qemuutil)
-qsd_ss.add_all(blockdev_ss)
+qsd_ss.add(blockdev, chardev, qmp, qom, qemuutil)
 
 subdir('qapi')
 
-- 
2.26.2

Block exports are used by softmmu, qemu-storage-daemon, and qemu-nbd.
They are not used by other programs and are not otherwise needed in
libblock.

Undo the recent move of blockdev-nbd.c from blockdev_ss into block_ss.
Since bdrv_close_all() (libblock) calls blk_exp_close_all()
(libblockdev) a stub function is required..

Make qemu-nbd.c use signal handling utility functions instead of
duplicating the code. This helps because os-posix.c is in libblockdev
and it depends on a qemu_system_killed() symbol that qemu-nbd.c lacks.
Once we use the signal handling utility functions we also end up
providing the necessary symbol.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20200929125516.186715-4-stefanha@redhat.com
[Fixed s/ndb/nbd/ typo in commit description as suggested by Eric Blake
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qemu-nbd.c                | 21 ++++++++-------------
 stubs/blk-exp-close-all.c |  7 +++++++
 block/export/meson.build  |  4 ++--
 meson.build               |  4 ++--
 nbd/meson.build           |  2 ++
 stubs/meson.build         |  1 +
 6 files changed, 22 insertions(+), 17 deletions(-)
 create mode 100644 stubs/blk-exp-close-all.c

diff --git a/qemu-nbd.c b/qemu-nbd.c
index XXXXXXX..XXXXXXX 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -XXX,XX +XXX,XX @@
 #include "qapi/error.h"
 #include "qemu/cutils.h"
 #include "sysemu/block-backend.h"
+#include "sysemu/runstate.h" /* for qemu_system_killed() prototype */
 #include "block/block_int.h"
 #include "block/nbd.h"
 #include "qemu/main-loop.h"
@@ -XXX,XX +XXX,XX @@ QEMU_COPYRIGHT "\n"
 }
 
 #ifdef CONFIG_POSIX
-static void termsig_handler(int signum)
+/*
+ * The client thread uses SIGTERM to interrupt the server.  A signal
+ * handler ensures that "qemu-nbd -v -c" exits with a nice status code.
+ */
+void qemu_system_killed(int signum, pid_t pid)
 {
     qatomic_cmpxchg(&state, RUNNING, TERMINATE);
     qemu_notify_event();
@@ -XXX,XX +XXX,XX @@ int main(int argc, char **argv)
     BlockExportOptions *export_opts;
 
 #ifdef CONFIG_POSIX
-    /*
-     * Exit gracefully on various signals, which includes SIGTERM used
-     * by 'qemu-nbd -v -c'.
-     */
-    struct sigaction sa_sigterm;
-    memset(&sa_sigterm, 0, sizeof(sa_sigterm));
-    sa_sigterm.sa_handler = termsig_handler;
-    sigaction(SIGTERM, &sa_sigterm, NULL);
-    sigaction(SIGINT, &sa_sigterm, NULL);
-    sigaction(SIGHUP, &sa_sigterm, NULL);
-
-    signal(SIGPIPE, SIG_IGN);
+    os_setup_early_signal_handling();
+    os_setup_signal_handling();
 #endif
 
     socket_init();
diff --git a/stubs/blk-exp-close-all.c b/stubs/blk-exp-close-all.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/stubs/blk-exp-close-all.c
@@ -XXX,XX +XXX,XX @@
+#include "qemu/osdep.h"
+#include "block/export.h"
+
+/* Only used in programs that support block exports (libblockdev.fa) */
+void blk_exp_close_all(void)
+{
+}
diff --git a/block/export/meson.build b/block/export/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/block/export/meson.build
+++ b/block/export/meson.build
@@ -XXX,XX +XXX,XX @@
-block_ss.add(files('export.c'))
-block_ss.add(when: ['CONFIG_LINUX', 'CONFIG_VHOST_USER'], if_true: files('vhost-user-blk-server.c'))
+blockdev_ss.add(files('export.c'))
+blockdev_ss.add(when: ['CONFIG_LINUX', 'CONFIG_VHOST_USER'], if_true: files('vhost-user-blk-server.c'))
diff --git a/meson.build b/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/meson.build
+++ b/meson.build
@@ -XXX,XX +XXX,XX @@ subdir('dump')
 
 block_ss.add(files(
   'block.c',
-  'blockdev-nbd.c',
   'blockjob.c',
   'job.c',
   'qemu-io-cmds.c',
@@ -XXX,XX +XXX,XX @@ subdir('block')
 
 blockdev_ss.add(files(
   'blockdev.c',
+  'blockdev-nbd.c',
   'iothread.c',
   'job-qmp.c',
 ))
@@ -XXX,XX +XXX,XX @@ if have_tools
   qemu_io = executable('qemu-io', files('qemu-io.c'),
              dependencies: [block, qemuutil], install: true)
   qemu_nbd = executable('qemu-nbd', files('qemu-nbd.c'),
-               dependencies: [block, qemuutil], install: true)
+               dependencies: [blockdev, qemuutil], install: true)
 
   subdir('storage-daemon')
   subdir('contrib/rdmacm-mux')
diff --git a/nbd/meson.build b/nbd/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/nbd/meson.build
+++ b/nbd/meson.build
@@ -XXX,XX +XXX,XX @@
 block_ss.add(files(
   'client.c',
   'common.c',
+))
+blockdev_ss.add(files(
   'server.c',
 ))
diff --git a/stubs/meson.build b/stubs/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -XXX,XX +XXX,XX @@
 stub_ss.add(files('arch_type.c'))
 stub_ss.add(files('bdrv-next-monitor-owned.c'))
 stub_ss.add(files('blk-commit-all.c'))
+stub_ss.add(files('blk-exp-close-all.c'))
 stub_ss.add(files('blockdev-close-all-bdrv-states.c'))
 stub_ss.add(files('change-state-handler.c'))
 stub_ss.add(files('cmos.c'))
-- 
2.26.2

Make it possible to specify the iothread where the export will run. By
default the block node can be moved to other AioContexts later and the
export will follow. The fixed-iothread option forces strict behavior
that prevents changing AioContext while the export is active. See the
QAPI docs for details.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200929125516.186715-5-stefanha@redhat.com
[Fix stray '#' character in block-export.json and add missing "(since:
5.2)" as suggested by Eric Blake.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qapi/block-export.json               | 11 ++++++++++
 block/export/export.c                | 31 +++++++++++++++++++++++++++-
 block/export/vhost-user-blk-server.c |  5 ++++-
 nbd/server.c                         |  2 --
 4 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/qapi/block-export.json b/qapi/block-export.json
index XXXXXXX..XXXXXXX 100644
--- a/qapi/block-export.json
+++ b/qapi/block-export.json
@@ -XXX,XX +XXX,XX @@
 #                export before completion is signalled. (since: 5.2;
 #                default: false)
 #
+# @iothread: The name of the iothread object where the export will run. The
+#            default is to use the thread currently associated with the
+#            block node. (since: 5.2)
+#
+# @fixed-iothread: True prevents the block node from being moved to another
+#                  thread while the export is active. If true and @iothread is
+#                  given, export creation fails if the block node cannot be
+#                  moved to the iothread. The default is false. (since: 5.2)
+#
 # Since: 4.2
 ##
 { 'union': 'BlockExportOptions',
   'base': { 'type': 'BlockExportType',
             'id': 'str',
+	    '*fixed-iothread': 'bool',
+	    '*iothread': 'str',
             'node-name': 'str',
             '*writable': 'bool',
             '*writethrough': 'bool' },
diff --git a/block/export/export.c b/block/export/export.c
index XXXXXXX..XXXXXXX 100644
--- a/block/export/export.c
+++ b/block/export/export.c
@@ -XXX,XX +XXX,XX @@
 
 #include "block/block.h"
 #include "sysemu/block-backend.h"
+#include "sysemu/iothread.h"
 #include "block/export.h"
 #include "block/nbd.h"
 #include "qapi/error.h"
@@ -XXX,XX +XXX,XX @@ static const BlockExportDriver *blk_exp_find_driver(BlockExportType type)
 
 BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
 {
+    bool fixed_iothread = export->has_fixed_iothread && export->fixed_iothread;
     const BlockExportDriver *drv;
     BlockExport *exp = NULL;
     BlockDriverState *bs;
-    BlockBackend *blk;
+    BlockBackend *blk = NULL;
     AioContext *ctx;
     uint64_t perm;
     int ret;
@@ -XXX,XX +XXX,XX @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
     ctx = bdrv_get_aio_context(bs);
     aio_context_acquire(ctx);
 
+    if (export->has_iothread) {
+        IOThread *iothread;
+        AioContext *new_ctx;
+
+        iothread = iothread_by_id(export->iothread);
+        if (!iothread) {
+            error_setg(errp, "iothread \"%s\" not found", export->iothread);
+            goto fail;
+        }
+
+        new_ctx = iothread_get_aio_context(iothread);
+
+        ret = bdrv_try_set_aio_context(bs, new_ctx, errp);
+        if (ret == 0) {
+            aio_context_release(ctx);
+            aio_context_acquire(new_ctx);
+            ctx = new_ctx;
+        } else if (fixed_iothread) {
+            goto fail;
+        }
+    }
+
     /*
      * Block exports are used for non-shared storage migration. Make sure
      * that BDRV_O_INACTIVE is cleared and the image is ready for write
@@ -XXX,XX +XXX,XX @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp)
     }
 
     blk = blk_new(ctx, perm, BLK_PERM_ALL);
+
+    if (!fixed_iothread) {
+        blk_set_allow_aio_context_change(blk, true);
+    }
+
     ret = blk_insert_bs(blk, bs, errp);
     if (ret < 0) {
         goto fail;
diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
index XXXXXXX..XXXXXXX 100644
--- a/block/export/vhost-user-blk-server.c
+++ b/block/export/vhost-user-blk-server.c
@@ -XXX,XX +XXX,XX @@ static const VuDevIface vu_blk_iface = {
 static void blk_aio_attached(AioContext *ctx, void *opaque)
 {
     VuBlkExport *vexp = opaque;
+
+    vexp->export.ctx = ctx;
     vhost_user_server_attach_aio_context(&vexp->vu_server, ctx);
 }
 
 static void blk_aio_detach(void *opaque)
 {
     VuBlkExport *vexp = opaque;
+
     vhost_user_server_detach_aio_context(&vexp->vu_server);
+    vexp->export.ctx = NULL;
 }
 
 static void
@@ -XXX,XX +XXX,XX @@ static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
     vu_blk_initialize_config(blk_bs(exp->blk), &vexp->blkcfg,
                                logical_block_size);
 
-    blk_set_allow_aio_context_change(exp->blk, true);
     blk_add_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
                                  vexp);
 
diff --git a/nbd/server.c b/nbd/server.c
index XXXXXXX..XXXXXXX 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -XXX,XX +XXX,XX @@ static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args,
         return ret;
     }
 
-    blk_set_allow_aio_context_change(blk, true);
-
     QTAILQ_INIT(&exp->clients);
     exp->name = g_strdup(arg->name);
     exp->description = g_strdup(arg->description);
-- 
2.26.2

Allow the number of queues to be configured using --export
vhost-user-blk,num-queues=N. This setting should match the QEMU --device
vhost-user-blk-pci,num-queues=N setting but QEMU vhost-user-blk.c lowers
its own value if the vhost-user-blk backend offers fewer queues than
QEMU.

The vhost-user-blk-server.c code is already capable of multi-queue. All
virtqueue processing runs in the same AioContext. No new locking is
needed.

Add the num-queues=N option and set the VIRTIO_BLK_F_MQ feature bit.
Note that the feature bit only announces the presence of the num_queues
configuration space field. It does not promise that there is more than 1
virtqueue, so we can set it unconditionally.

I tested multi-queue by running a random read fio test with numjobs=4 on
an -smp 4 guest. After the benchmark finished the guest /proc/interrupts
file showed activity on all 4 virtio-blk MSI-X. The /sys/block/vda/mq/
directory shows that Linux blk-mq has 4 queues configured.

An automated test is included in the next commit.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20201001144604.559733-2-stefanha@redhat.com
[Fixed accidental tab characters as suggested by Markus Armbruster
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qapi/block-export.json               | 10 +++++++---
 block/export/vhost-user-blk-server.c | 24 ++++++++++++++++++------
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/qapi/block-export.json b/qapi/block-export.json
index XXXXXXX..XXXXXXX 100644
--- a/qapi/block-export.json
+++ b/qapi/block-export.json
@@ -XXX,XX +XXX,XX @@
 #        SocketAddress types are supported. Passed fds must be UNIX domain
 #        sockets.
 # @logical-block-size: Logical block size in bytes. Defaults to 512 bytes.
+# @num-queues: Number of request virtqueues. Must be greater than 0. Defaults
+#              to 1.
 #
 # Since: 5.2
 ##
 { 'struct': 'BlockExportOptionsVhostUserBlk',
-  'data': { 'addr': 'SocketAddress', '*logical-block-size': 'size' } }
+  'data': { 'addr': 'SocketAddress',
+	    '*logical-block-size': 'size',
+            '*num-queues': 'uint16'} }
 
 ##
 # @NbdServerAddOptions:
@@ -XXX,XX +XXX,XX @@
 { 'union': 'BlockExportOptions',
   'base': { 'type': 'BlockExportType',
             'id': 'str',
-	    '*fixed-iothread': 'bool',
-	    '*iothread': 'str',
+            '*fixed-iothread': 'bool',
+            '*iothread': 'str',
             'node-name': 'str',
             '*writable': 'bool',
             '*writethrough': 'bool' },
diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
index XXXXXXX..XXXXXXX 100644
--- a/block/export/vhost-user-blk-server.c
+++ b/block/export/vhost-user-blk-server.c
@@ -XXX,XX +XXX,XX @@
 #include "util/block-helpers.h"
 
 enum {
-    VHOST_USER_BLK_MAX_QUEUES = 1,
+    VHOST_USER_BLK_NUM_QUEUES_DEFAULT = 1,
 };
 struct virtio_blk_inhdr {
     unsigned char status;
@@ -XXX,XX +XXX,XX @@ static uint64_t vu_blk_get_features(VuDev *dev)
                1ull << VIRTIO_BLK_F_DISCARD |
                1ull << VIRTIO_BLK_F_WRITE_ZEROES |
                1ull << VIRTIO_BLK_F_CONFIG_WCE |
+               1ull << VIRTIO_BLK_F_MQ |
                1ull << VIRTIO_F_VERSION_1 |
                1ull << VIRTIO_RING_F_INDIRECT_DESC |
                1ull << VIRTIO_RING_F_EVENT_IDX |
@@ -XXX,XX +XXX,XX @@ static void blk_aio_detach(void *opaque)
 
 static void
 vu_blk_initialize_config(BlockDriverState *bs,
-                           struct virtio_blk_config *config, uint32_t blk_size)
+                         struct virtio_blk_config *config,
+                         uint32_t blk_size,
+                         uint16_t num_queues)
 {
     config->capacity = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
     config->blk_size = blk_size;
@@ -XXX,XX +XXX,XX @@ vu_blk_initialize_config(BlockDriverState *bs,
     config->seg_max = 128 - 2;
     config->min_io_size = 1;
     config->opt_io_size = 1;
-    config->num_queues = VHOST_USER_BLK_MAX_QUEUES;
+    config->num_queues = num_queues;
     config->max_discard_sectors = 32768;
     config->max_discard_seg = 1;
     config->discard_sector_alignment = config->blk_size >> 9;
@@ -XXX,XX +XXX,XX @@ static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
     BlockExportOptionsVhostUserBlk *vu_opts = &opts->u.vhost_user_blk;
     Error *local_err = NULL;
     uint64_t logical_block_size;
+    uint16_t num_queues = VHOST_USER_BLK_NUM_QUEUES_DEFAULT;
 
     vexp->writable = opts->writable;
     vexp->blkcfg.wce = 0;
@@ -XXX,XX +XXX,XX @@ static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts,
     }
     vexp->blk_size = logical_block_size;
     blk_set_guest_block_size(exp->blk, logical_block_size);
+
+    if (vu_opts->has_num_queues) {
+        num_queues = vu_opts->num_queues;
+    }
+    if (num_queues == 0) {
+        error_setg(errp, "num-queues must be greater than 0");
+        return -EINVAL;
+    }
+
     vu_blk_initialize_config(blk_bs(exp->blk), &vexp->blkcfg,
-                               logical_block_size);
+                             logical_block_size, num_queues);
 
     blk_add_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach,
                                  vexp);
 
     if (!vhost_user_server_start(&vexp->vu_server, vu_opts->addr, exp->ctx,
-                                 VHOST_USER_BLK_MAX_QUEUES, &vu_blk_iface,
-                                 errp)) {
+                                 num_queues, &vu_blk_iface, errp)) {
         blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
                                         blk_aio_detach, vexp);
         return -EADDRNOTAVAIL;
-- 
2.26.2

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

bdrv_co_block_status_above has several design problems with handling
short backing files:

1. With want_zeros=true, it may return ret with BDRV_BLOCK_ZERO but
without BDRV_BLOCK_ALLOCATED flag, when actually short backing file
which produces these after-EOF zeros is inside requested backing
sequence.

2. With want_zero=false, it may return pnum=0 prior to actual EOF,
because of EOF of short backing file.

Fix these things, making logic about short backing files clearer.

With fixed bdrv_block_status_above we also have to improve is_zero in
qcow2 code, otherwise iotest 154 will fail, because with this patch we
stop to merge zeros of different types (produced by fully unallocated
in the whole backing chain regions vs produced by short backing files).

Note also, that this patch leaves for another day the general problem
around block-status: misuse of BDRV_BLOCK_ALLOCATED as is-fs-allocated
vs go-to-backing.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20200924194003.22080-2-vsementsov@virtuozzo.com
[Fix s/comes/come/ as suggested by Eric Blake
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io.c    | 68 ++++++++++++++++++++++++++++++++++++++++-----------
 block/qcow2.c | 16 ++++++++++--
 2 files changed, 68 insertions(+), 16 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
                                   int64_t *map,
                                   BlockDriverState **file)
 {
+    int ret;
     BlockDriverState *p;
-    int ret = 0;
-    bool first = true;
+    int64_t eof = 0;
 
     assert(bs != base);
-    for (p = bs; p != base; p = bdrv_filter_or_cow_bs(p)) {
+
+    ret = bdrv_co_block_status(bs, want_zero, offset, bytes, pnum, map, file);
+    if (ret < 0 || *pnum == 0 || ret & BDRV_BLOCK_ALLOCATED) {
+        return ret;
+    }
+
+    if (ret & BDRV_BLOCK_EOF) {
+        eof = offset + *pnum;
+    }
+
+    assert(*pnum <= bytes);
+    bytes = *pnum;
+
+    for (p = bdrv_filter_or_cow_bs(bs); p != base;
+         p = bdrv_filter_or_cow_bs(p))
+    {
         ret = bdrv_co_block_status(p, want_zero, offset, bytes, pnum, map,
                                    file);
         if (ret < 0) {
-            break;
+            return ret;
         }
-        if (ret & BDRV_BLOCK_ZERO && ret & BDRV_BLOCK_EOF && !first) {
+        if (*pnum == 0) {
             /*
-             * Reading beyond the end of the file continues to read
-             * zeroes, but we can only widen the result to the
-             * unallocated length we learned from an earlier
-             * iteration.
+             * The top layer deferred to this layer, and because this layer is
+             * short, any zeroes that we synthesize beyond EOF behave as if they
+             * were allocated at this layer.
+             *
+             * We don't include BDRV_BLOCK_EOF into ret, as upper layer may be
+             * larger. We'll add BDRV_BLOCK_EOF if needed at function end, see
+             * below.
              */
+            assert(ret & BDRV_BLOCK_EOF);
             *pnum = bytes;
+            if (file) {
+                *file = p;
+            }
+            ret = BDRV_BLOCK_ZERO | BDRV_BLOCK_ALLOCATED;
+            break;
         }
-        if (ret & (BDRV_BLOCK_ZERO | BDRV_BLOCK_DATA)) {
+        if (ret & BDRV_BLOCK_ALLOCATED) {
+            /*
+             * We've found the node and the status, we must break.
+             *
+             * Drop BDRV_BLOCK_EOF, as it's not for upper layer, which may be
+             * larger. We'll add BDRV_BLOCK_EOF if needed at function end, see
+             * below.
+             */
+            ret &= ~BDRV_BLOCK_EOF;
             break;
         }
-        /* [offset, pnum] unallocated on this layer, which could be only
-         * the first part of [offset, bytes].  */
-        bytes = MIN(bytes, *pnum);
-        first = false;
+
+        /*
+         * OK, [offset, offset + *pnum) region is unallocated on this layer,
+         * let's continue the diving.
+         */
+        assert(*pnum <= bytes);
+        bytes = *pnum;
+    }
+
+    if (offset + *pnum == eof) {
+        ret |= BDRV_BLOCK_EOF;
     }
+
     return ret;
 }
 
diff --git a/block/qcow2.c b/block/qcow2.c
index XXXXXXX..XXXXXXX 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -XXX,XX +XXX,XX @@ static bool is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes)
     if (!bytes) {
         return true;
     }
-    res = bdrv_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL);
-    return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == bytes;
+
+    /*
+     * bdrv_block_status_above doesn't merge different types of zeros, for
+     * example, zeros which come from the region which is unallocated in
+     * the whole backing chain, and zeros which come because of a short
+     * backing file. So, we need a loop.
+     */
+    do {
+        res = bdrv_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL);
+        offset += nr;
+        bytes -= nr;
+    } while (res >= 0 && (res & BDRV_BLOCK_ZERO) && nr && bytes);
+
+    return res >= 0 && (res & BDRV_BLOCK_ZERO) && bytes == 0;
 }
 
 static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
-- 
2.26.2

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

In order to reuse bdrv_common_block_status_above in
bdrv_is_allocated_above, let's support include_base parameter.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20200924194003.22080-3-vsementsov@virtuozzo.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/coroutines.h |  2 ++
 block/io.c         | 21 ++++++++++++++-------
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/block/coroutines.h b/block/coroutines.h
index XXXXXXX..XXXXXXX 100644
--- a/block/coroutines.h
+++ b/block/coroutines.h
@@ -XXX,XX +XXX,XX @@ bdrv_pwritev(BdrvChild *child, int64_t offset, unsigned int bytes,
 int coroutine_fn
 bdrv_co_common_block_status_above(BlockDriverState *bs,
                                   BlockDriverState *base,
+                                  bool include_base,
                                   bool want_zero,
                                   int64_t offset,
                                   int64_t bytes,
@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
 int generated_co_wrapper
 bdrv_common_block_status_above(BlockDriverState *bs,
                                BlockDriverState *base,
+                               bool include_base,
                                bool want_zero,
                                int64_t offset,
                                int64_t bytes,
diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ early_out:
 int coroutine_fn
 bdrv_co_common_block_status_above(BlockDriverState *bs,
                                   BlockDriverState *base,
+                                  bool include_base,
                                   bool want_zero,
                                   int64_t offset,
                                   int64_t bytes,
@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
     BlockDriverState *p;
     int64_t eof = 0;
 
-    assert(bs != base);
+    assert(include_base || bs != base);
+    assert(!include_base || base); /* Can't include NULL base */
 
     ret = bdrv_co_block_status(bs, want_zero, offset, bytes, pnum, map, file);
-    if (ret < 0 || *pnum == 0 || ret & BDRV_BLOCK_ALLOCATED) {
+    if (ret < 0 || *pnum == 0 || ret & BDRV_BLOCK_ALLOCATED || bs == base) {
         return ret;
     }
 
@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
     assert(*pnum <= bytes);
     bytes = *pnum;
 
-    for (p = bdrv_filter_or_cow_bs(bs); p != base;
+    for (p = bdrv_filter_or_cow_bs(bs); include_base || p != base;
          p = bdrv_filter_or_cow_bs(p))
     {
         ret = bdrv_co_block_status(p, want_zero, offset, bytes, pnum, map,
@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
             break;
         }
 
+        if (p == base) {
+            assert(include_base);
+            break;
+        }
+
         /*
          * OK, [offset, offset + *pnum) region is unallocated on this layer,
          * let's continue the diving.
@@ -XXX,XX +XXX,XX @@ int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base,
                             int64_t offset, int64_t bytes, int64_t *pnum,
                             int64_t *map, BlockDriverState **file)
 {
-    return bdrv_common_block_status_above(bs, base, true, offset, bytes,
+    return bdrv_common_block_status_above(bs, base, false, true, offset, bytes,
                                           pnum, map, file);
 }
 
@@ -XXX,XX +XXX,XX @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t offset,
     int ret;
     int64_t dummy;
 
-    ret = bdrv_common_block_status_above(bs, bdrv_filter_or_cow_bs(bs), false,
-                                         offset, bytes, pnum ? pnum : &dummy,
-                                         NULL, NULL);
+    ret = bdrv_common_block_status_above(bs, bs, true, false, offset,
+                                         bytes, pnum ? pnum : &dummy, NULL,
+                                         NULL);
     if (ret < 0) {
         return ret;
     }
-- 
2.26.2

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

We are going to reuse bdrv_common_block_status_above in
bdrv_is_allocated_above. bdrv_is_allocated_above may be called with
include_base == false and still bs == base (for ex. from img_rebase()).

So, support this corner case.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20200924194003.22080-4-vsementsov@virtuozzo.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
     BlockDriverState *p;
     int64_t eof = 0;
 
-    assert(include_base || bs != base);
     assert(!include_base || base); /* Can't include NULL base */
 
+    if (!include_base && bs == base) {
+        *pnum = bytes;
+        return 0;
+    }
+
     ret = bdrv_co_block_status(bs, want_zero, offset, bytes, pnum, map, file);
     if (ret < 0 || *pnum == 0 || ret & BDRV_BLOCK_ALLOCATED || bs == base) {
         return ret;
-- 
2.26.2

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

bdrv_is_allocated_above wrongly handles short backing files: it reports
after-EOF space as UNALLOCATED which is wrong, as on read the data is
generated on the level of short backing file (if all overlays have
unallocated areas at that place).

Reusing bdrv_common_block_status_above fixes the issue and unifies code
path.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20200924194003.22080-5-vsementsov@virtuozzo.com
[Fix s/has/have/ as suggested by Eric Blake. Fix s/area/areas/.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io.c | 43 +++++--------------------------------------
 1 file changed, 5 insertions(+), 38 deletions(-)

diff --git a/block/io.c b/block/io.c
index XXXXXXX..XXXXXXX 100644
--- a/block/io.c
+++ b/block/io.c
@@ -XXX,XX +XXX,XX @@ int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t offset,
  * at 'offset + *pnum' may return the same allocation status (in other
  * words, the result is not necessarily the maximum possible range);
  * but 'pnum' will only be 0 when end of file is reached.
- *
  */
 int bdrv_is_allocated_above(BlockDriverState *top,
                             BlockDriverState *base,
                             bool include_base, int64_t offset,
                             int64_t bytes, int64_t *pnum)
 {
-    BlockDriverState *intermediate;
-    int ret;
-    int64_t n = bytes;
-
-    assert(base || !include_base);
-
-    intermediate = top;
-    while (include_base || intermediate != base) {
-        int64_t pnum_inter;
-        int64_t size_inter;
-
-        assert(intermediate);
-        ret = bdrv_is_allocated(intermediate, offset, bytes, &pnum_inter);
-        if (ret < 0) {
-            return ret;
-        }
-        if (ret) {
-            *pnum = pnum_inter;
-            return 1;
-        }
-
-        size_inter = bdrv_getlength(intermediate);
-        if (size_inter < 0) {
-            return size_inter;
-        }
-        if (n > pnum_inter &&
-            (intermediate == top || offset + pnum_inter < size_inter)) {
-            n = pnum_inter;
-        }
-
-        if (intermediate == base) {
-            break;
-        }
-
-        intermediate = bdrv_filter_or_cow_bs(intermediate);
+    int ret = bdrv_common_block_status_above(top, base, include_base, false,
+                                             offset, bytes, pnum, NULL, NULL);
+    if (ret < 0) {
+        return ret;
     }
 
-    *pnum = n;
-    return 0;
+    return !!(ret & BDRV_BLOCK_ALLOCATED);
 }
 
 int coroutine_fn
-- 
2.26.2

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

These cases are fixed by previous patches around block_status and
is_allocated.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20200924194003.22080-6-vsementsov@virtuozzo.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 tests/qemu-iotests/274     | 20 +++++++++++
 tests/qemu-iotests/274.out | 68 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+)

diff --git a/tests/qemu-iotests/274 b/tests/qemu-iotests/274
index XXXXXXX..XXXXXXX 100755
--- a/tests/qemu-iotests/274
+++ b/tests/qemu-iotests/274
@@ -XXX,XX +XXX,XX @@ with iotests.FilePath('base') as base, \
     iotests.qemu_io_log('-c', 'read -P 1 0 %d' % size_short, mid)
     iotests.qemu_io_log('-c', 'read -P 0 %d %d' % (size_short, size_diff), mid)
 
+    iotests.log('=== Testing qemu-img commit (top -> base) ===')
+
+    create_chain()
+    iotests.qemu_img_log('commit', '-b', base, top)
+    iotests.img_info_log(base)
+    iotests.qemu_io_log('-c', 'read -P 1 0 %d' % size_short, base)
+    iotests.qemu_io_log('-c', 'read -P 0 %d %d' % (size_short, size_diff), base)
+
+    iotests.log('=== Testing QMP active commit (top -> base) ===')
+
+    create_chain()
+    with create_vm() as vm:
+        vm.launch()
+        vm.qmp_log('block-commit', device='top', base_node='base',
+                   job_id='job0', auto_dismiss=False)
+        vm.run_job('job0', wait=5)
+
+    iotests.img_info_log(mid)
+    iotests.qemu_io_log('-c', 'read -P 1 0 %d' % size_short, base)
+    iotests.qemu_io_log('-c', 'read -P 0 %d %d' % (size_short, size_diff), base)
 
     iotests.log('== Resize tests ==')
 
diff --git a/tests/qemu-iotests/274.out b/tests/qemu-iotests/274.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/274.out
+++ b/tests/qemu-iotests/274.out
@@ -XXX,XX +XXX,XX @@ read 1048576/1048576 bytes at offset 0
 read 1048576/1048576 bytes at offset 1048576
 1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
+=== Testing qemu-img commit (top -> base) ===
+Formatting 'TEST_DIR/PID-base', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=2097152 lazy_refcounts=off refcount_bits=16
+
+Formatting 'TEST_DIR/PID-mid', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=1048576 backing_file=TEST_DIR/PID-base backing_fmt=qcow2 lazy_refcounts=off refcount_bits=16
+
+Formatting 'TEST_DIR/PID-top', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=2097152 backing_file=TEST_DIR/PID-mid backing_fmt=qcow2 lazy_refcounts=off refcount_bits=16
+
+wrote 2097152/2097152 bytes at offset 0
+2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+Image committed.
+
+image: TEST_IMG
+file format: IMGFMT
+virtual size: 2 MiB (2097152 bytes)
+cluster_size: 65536
+Format specific information:
+    compat: 1.1
+    compression type: zlib
+    lazy refcounts: false
+    refcount bits: 16
+    corrupt: false
+    extended l2: false
+
+read 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+read 1048576/1048576 bytes at offset 1048576
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+=== Testing QMP active commit (top -> base) ===
+Formatting 'TEST_DIR/PID-base', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=2097152 lazy_refcounts=off refcount_bits=16
+
+Formatting 'TEST_DIR/PID-mid', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=1048576 backing_file=TEST_DIR/PID-base backing_fmt=qcow2 lazy_refcounts=off refcount_bits=16
+
+Formatting 'TEST_DIR/PID-top', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=2097152 backing_file=TEST_DIR/PID-mid backing_fmt=qcow2 lazy_refcounts=off refcount_bits=16
+
+wrote 2097152/2097152 bytes at offset 0
+2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+{"execute": "block-commit", "arguments": {"auto-dismiss": false, "base-node": "base", "device": "top", "job-id": "job0"}}
+{"return": {}}
+{"execute": "job-complete", "arguments": {"id": "job0"}}
+{"return": {}}
+{"data": {"device": "job0", "len": 1048576, "offset": 1048576, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_READY", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"data": {"device": "job0", "len": 1048576, "offset": 1048576, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"execute": "job-dismiss", "arguments": {"id": "job0"}}
+{"return": {}}
+image: TEST_IMG
+file format: IMGFMT
+virtual size: 1 MiB (1048576 bytes)
+cluster_size: 65536
+backing file: TEST_DIR/PID-base
+backing file format: IMGFMT
+Format specific information:
+    compat: 1.1
+    compression type: zlib
+    lazy refcounts: false
+    refcount bits: 16
+    corrupt: false
+    extended l2: false
+
+read 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+read 1048576/1048576 bytes at offset 1048576
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
 == Resize tests ==
 === preallocation=off ===
 Formatting 'TEST_DIR/PID-base', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=6442450944 lazy_refcounts=off refcount_bits=16
-- 
2.26.2