Series comparison

-[Qemu-devel] [PULL 0/3] Block patches
+[PULL 0/5] Block patches
-The following changes since commit ab08440a4ee09032d1a9cb22fdcab23bc7e1c656:
+The following changes since commit 711c0418c8c1ce3a24346f058b001c4c5a2f0f81:
-  Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20180702' into staging (2018-07-02 17:57:46 +0100)
+  Merge remote-tracking branch 'remotes/philmd/tags/mips-20210702' into staging (2021-07-04 14:04:12 +0100)
 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 9ded4a0114968e98b41494fc035ba14f84cdf700:
+for you to fetch changes up to 9f460c64e13897117f35ffb61f6f5e0102cabc70:
-  backup: Use copy offloading (2018-07-02 23:23:45 -0400)
+  block/io: Merge discard request alignments (2021-07-06 14:28:55 +0100)
 ----------------------------------------------------------------
-Block backup patches
+Pull request
 ----------------------------------------------------------------
-Fam Zheng (3):
+Akihiko Odaki (3):
-  block: Fix parameter checking in bdrv_co_copy_range_internal
+  block/file-posix: Optimize for macOS
-  block: Honour BDRV_REQ_NO_SERIALISING in copy range
+  block: Add backend_defaults property
-  backup: Use copy offloading
+  block/io: Merge discard request alignments
- block/backup.c        | 150 ++++++++++++++++++++++++++++++------------
+Stefan Hajnoczi (2):
- block/io.c            |  35 +++++-----
+  util/async: add a human-readable name to BHs for debugging
- block/trace-events    |   1 +
+  util/async: print leaked BH name when AioContext finalizes
- include/block/block.h |   5 +-
-files changed, 132 insertions(+), 59 deletions(-)
+ include/block/aio.h            | 31 ++++++++++++++++++++++---
  include/hw/block/block.h       |  3 +++
  include/qemu/main-loop.h       |  4 +++-
  block/file-posix.c             | 27 ++++++++++++++++++++--
  block/io.c                     |  2 ++
  hw/block/block.c               | 42 ++++++++++++++++++++++++++++++----
  tests/unit/ptimer-test-stubs.c |  2 +-
  util/async.c                   | 25 ++++++++++++++++----
  util/main-loop.c               |  4 ++--
  tests/qemu-iotests/172.out     | 38 ++++++++++++++++++++++++++++++
 files changed, 161 insertions(+), 17 deletions(-)
 --
-.17.1
+.31.1

-[Qemu-devel] [PULL 1/3] block: Fix parameter checking in bdrv_co_copy_range_internal
+[PULL 1/5] util/async: add a human-readable name to BHs for debugging
-From: Fam Zheng <famz@redhat.com>
+It can be difficult to debug issues with BHs in production environments.
 Although BHs can usually be identified by looking up their ->cb()
 function pointer, this requires debug information for the program. It is
 also not possible to print human-readable diagnostics about BHs because
 they have no identifier.
-src may be NULL if BDRV_REQ_ZERO_WRITE flag is set, in this case only
+This patch adds a name to each BH. The name is not unique per instance
-check dst and dst->bs. This bug was introduced when moving in the
+but differentiates between cb() functions, which is usually enough. It's
-request tracking code from bdrv_co_copy_range, in 37aec7d75eb.
+done by changing aio_bh_new() and friends to macros that stringify cb.
-This especially fixes the possible segfault when initializing src_bs
+The next patch will use the name field when reporting leaked BHs.
 with a NULL src.
-Signed-off-by: Fam Zheng <famz@redhat.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-Message-id: 20180703023758.14422-2-famz@redhat.com
+Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
-Reviewed-by: Jeff Cody <jcody@redhat.com>
+Message-Id: <20210414200247.917496-2-stefanha@redhat.com>
 Signed-off-by: Jeff Cody <jcody@redhat.com>
 ---
- block/io.c | 29 +++++++++++++++--------------
+ include/block/aio.h            | 31 ++++++++++++++++++++++++++++---
-file changed, 15 insertions(+), 14 deletions(-)
+ include/qemu/main-loop.h       |  4 +++-
  tests/unit/ptimer-test-stubs.c |  2 +-
  util/async.c                   |  9 +++++++--
  util/main-loop.c               |  4 ++--
 files changed, 41 insertions(+), 9 deletions(-)
-diff --git a/block/io.c b/block/io.c
+diff --git a/include/block/aio.h b/include/block/aio.h
 index XXXXXXX..XXXXXXX 100644
---- a/block/io.c
+--- a/include/block/aio.h
-+++ b/block/io.c
++++ b/include/block/aio.h
-@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,
+@@ -XXX,XX +XXX,XX @@ void aio_context_acquire(AioContext *ctx);
-                                                     bool recurse_src)
+ /* Relinquish ownership of the AioContext. */
  void aio_context_release(AioContext *ctx);
 +/**
 + * aio_bh_schedule_oneshot_full: Allocate a new bottom half structure that will
 + * run only once and as soon as possible.
 + *
 + * @name: A human-readable identifier for debugging purposes.
 + */
 +void aio_bh_schedule_oneshot_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
 +                                  const char *name);
 +
  /**
   * aio_bh_schedule_oneshot: Allocate a new bottom half structure that will run
   * only once and as soon as possible.
 + *
 + * A convenience wrapper for aio_bh_schedule_oneshot_full() that uses cb as the
 + * name string.
   */
 -void aio_bh_schedule_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque);
 +#define aio_bh_schedule_oneshot(ctx, cb, opaque) \
 +    aio_bh_schedule_oneshot_full((ctx), (cb), (opaque), (stringify(cb)))
  /**
 - * aio_bh_new: Allocate a new bottom half structure.
 + * aio_bh_new_full: Allocate a new bottom half structure.
   *
   * Bottom halves are lightweight callbacks whose invocation is guaranteed
   * to be wait-free, thread-safe and signal-safe.  The #QEMUBH structure
   * is opaque and must be allocated prior to its use.
 + *
 + * @name: A human-readable identifier for debugging purposes.
   */
 -QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque);
 +QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
 +                        const char *name);
 +
 +/**
 + * aio_bh_new: Allocate a new bottom half structure
 + *
 + * A convenience wrapper for aio_bh_new_full() that uses the cb as the name
 + * string.
 + */
 +#define aio_bh_new(ctx, cb, opaque) \
 +    aio_bh_new_full((ctx), (cb), (opaque), (stringify(cb)))
  /**
   * aio_notify: Force processing of pending events.
 diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/qemu/main-loop.h
 +++ b/include/qemu/main-loop.h
@@ -XXX,XX +XXX,XX @@ void qemu_cond_timedwait_iothread(QemuCond *cond, int ms);
  void qemu_fd_register(int fd);
 -QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque);
 +#define qemu_bh_new(cb, opaque) \
 +    qemu_bh_new_full((cb), (opaque), (stringify(cb)))
 +QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name);
  void qemu_bh_schedule_idle(QEMUBH *bh);
  enum {
 diff --git a/tests/unit/ptimer-test-stubs.c b/tests/unit/ptimer-test-stubs.c
 index XXXXXXX..XXXXXXX 100644
 --- a/tests/unit/ptimer-test-stubs.c
 +++ b/tests/unit/ptimer-test-stubs.c
@@ -XXX,XX +XXX,XX @@ int64_t qemu_clock_deadline_ns_all(QEMUClockType type, int attr_mask)
      return deadline;
  }
 -QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
 +QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name)
  {
-     BdrvTrackedRequest src_req, dst_req;
+     QEMUBH *bh = g_new(QEMUBH, 1);
--    BlockDriverState *src_bs = src->bs;
--    BlockDriverState *dst_bs = dst->bs;
+diff --git a/util/async.c b/util/async.c
-     int ret;
+index XXXXXXX..XXXXXXX 100644
+--- a/util/async.c
--    if (!src || !dst || !src->bs || !dst->bs) {
++++ b/util/async.c
-+    if (!dst || !dst->bs) {
+@@ -XXX,XX +XXX,XX @@ enum {
-         return -ENOMEDIUM;
-     }
+ struct QEMUBH {
--    ret = bdrv_check_byte_request(src->bs, src_offset, bytes);
+     AioContext *ctx;
--    if (ret) {
++    const char *name;
--        return ret;
+     QEMUBHFunc *cb;
--    }
+     void *opaque;
--
+     QSLIST_ENTRY(QEMUBH) next;
-     ret = bdrv_check_byte_request(dst->bs, dst_offset, bytes);
+@@ -XXX,XX +XXX,XX @@ static QEMUBH *aio_bh_dequeue(BHList *head, unsigned *flags)
-     if (ret) {
+     return bh;
          return ret;
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,
          return bdrv_co_pwrite_zeroes(dst, dst_offset, bytes, flags);
      }
 +    if (!src || !src->bs) {
 +        return -ENOMEDIUM;
 +    }
 +    ret = bdrv_check_byte_request(src->bs, src_offset, bytes);
 +    if (ret) {
 +        return ret;
 +    }
 +
      if (!src->bs->drv->bdrv_co_copy_range_from
          || !dst->bs->drv->bdrv_co_copy_range_to
          || src->bs->encrypted || dst->bs->encrypted) {
          return -ENOTSUP;
      }
 -    bdrv_inc_in_flight(src_bs);
 -    bdrv_inc_in_flight(dst_bs);
 -    tracked_request_begin(&src_req, src_bs, src_offset,
 +    bdrv_inc_in_flight(src->bs);
 +    bdrv_inc_in_flight(dst->bs);
 +    tracked_request_begin(&src_req, src->bs, src_offset,
                            bytes, BDRV_TRACKED_READ);
 -    tracked_request_begin(&dst_req, dst_bs, dst_offset,
 +    tracked_request_begin(&dst_req, dst->bs, dst_offset,
                            bytes, BDRV_TRACKED_WRITE);
      wait_serialising_requests(&src_req);
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,
      }
      tracked_request_end(&src_req);
      tracked_request_end(&dst_req);
 -    bdrv_dec_in_flight(src_bs);
 -    bdrv_dec_in_flight(dst_bs);
 +    bdrv_dec_in_flight(src->bs);
 +    bdrv_dec_in_flight(dst->bs);
      return ret;
  }
+-void aio_bh_schedule_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
++void aio_bh_schedule_oneshot_full(AioContext *ctx, QEMUBHFunc *cb,
++                                  void *opaque, const char *name)
+ {
+     QEMUBH *bh;
+     bh = g_new(QEMUBH, 1);
+@@ -XXX,XX +XXX,XX @@ void aio_bh_schedule_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
+         .ctx = ctx,
+         .cb = cb,
+         .opaque = opaque,
++        .name = name,
+     };
+     aio_bh_enqueue(bh, BH_SCHEDULED | BH_ONESHOT);
+ }
+-QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
++QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
++                        const char *name)
+ {
+     QEMUBH *bh;
+     bh = g_new(QEMUBH, 1);
+@@ -XXX,XX +XXX,XX @@ QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
+         .ctx = ctx,
+         .cb = cb,
+         .opaque = opaque,
++        .name = name,
+     };
+     return bh;
+ }
+diff --git a/util/main-loop.c b/util/main-loop.c
+index XXXXXXX..XXXXXXX 100644
+--- a/util/main-loop.c
++++ b/util/main-loop.c
+@@ -XXX,XX +XXX,XX @@ void main_loop_wait(int nonblocking)
+ /* Functions to operate on the main QEMU AioContext.  */
+-QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
++QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name)
+ {
+-    return aio_bh_new(qemu_aio_context, cb, opaque);
++    return aio_bh_new_full(qemu_aio_context, cb, opaque, name);
+ }
+ /*
 --
-.17.1
+.31.1

-New patch
+[PULL 2/5] util/async: print leaked BH name when AioContext finalizes
+BHs must be deleted before the AioContext is finalized. If not, it's a
+bug and probably indicates that some part of the program still expects
+the BH to run in the future. That can lead to memory leaks, inconsistent
+state, or just hangs.
+Unfortunately the assert(flags & BH_DELETED) call in aio_ctx_finalize()
+is difficult to debug because the assertion failure contains no
+information about the BH!
+Use the QEMUBH name field added in the previous patch to show a useful
+error when a leaked BH is detected.
+Suggested-by: Eric Ernst <eric.g.ernst@gmail.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Message-Id: <20210414200247.917496-3-stefanha@redhat.com>
+---
+ util/async.c | 16 ++++++++++++++--
+file changed, 14 insertions(+), 2 deletions(-)
+diff --git a/util/async.c b/util/async.c
+index XXXXXXX..XXXXXXX 100644
+--- a/util/async.c
++++ b/util/async.c
+@@ -XXX,XX +XXX,XX @@ aio_ctx_finalize(GSource     *source)
+     assert(QSIMPLEQ_EMPTY(&ctx->bh_slice_list));
+     while ((bh = aio_bh_dequeue(&ctx->bh_list, &flags))) {
+-        /* qemu_bh_delete() must have been called on BHs in this AioContext */
+-        assert(flags & BH_DELETED);
++        /*
++         * qemu_bh_delete() must have been called on BHs in this AioContext. In
++         * many cases memory leaks, hangs, or inconsistent state occur when a
++         * BH is leaked because something still expects it to run.
++         *
++         * If you hit this, fix the lifecycle of the BH so that
++         * qemu_bh_delete() and any associated cleanup is called before the
++         * AioContext is finalized.
++         */
++        if (unlikely(!(flags & BH_DELETED))) {
++            fprintf(stderr, "%s: BH '%s' leaked, aborting...\n",
++                    __func__, bh->name);
++            abort();
++        }
+         g_free(bh);
+     }
+--
+.31.1

-[Qemu-devel] [PULL 3/3] backup: Use copy offloading
+[PULL 3/5] block/file-posix: Optimize for macOS
-From: Fam Zheng <famz@redhat.com>
+From: Akihiko Odaki <akihiko.odaki@gmail.com>
-The implementation is similar to the 'qemu-img convert'. In the
+This commit introduces "punch hole" operation and optimizes transfer
-beginning of the job, offloaded copy is attempted. If it fails, further
+block size for macOS.
 I/O will go through the existing bounce buffer code path.
-Then, as Kevin pointed out, both this and qemu-img convert can benefit
+Thanks to Konstantin Nazarov for detailed analysis of a flaw in an
-from a local check if one request fails because of, for example, the
+old version of this change:
-offset is beyond EOF, but another may well be accepted by the protocol
+https://gist.github.com/akihikodaki/87df4149e7ca87f18dc56807ec5a1bc5#gistcomment-3654667
 layer. This will be implemented separately.
-Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
-Signed-off-by: Fam Zheng <famz@redhat.com>
+Message-id: 20210705130458.97642-1-akihiko.odaki@gmail.com
-Message-id: 20180703023758.14422-4-famz@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 Signed-off-by: Jeff Cody <jcody@redhat.com>
 ---
- block/backup.c     | 150 ++++++++++++++++++++++++++++++++-------------
+ block/file-posix.c | 27 +++++++++++++++++++++++++--
- block/trace-events |   1 +
+file changed, 25 insertions(+), 2 deletions(-)
 files changed, 110 insertions(+), 41 deletions(-)
-diff --git a/block/backup.c b/block/backup.c
+diff --git a/block/file-posix.c b/block/file-posix.c
 index XXXXXXX..XXXXXXX 100644
---- a/block/backup.c
+--- a/block/file-posix.c
-+++ b/block/backup.c
++++ b/block/file-posix.c
-@@ -XXX,XX +XXX,XX @@ typedef struct BackupBlockJob {
+@@ -XXX,XX +XXX,XX @@
-     QLIST_HEAD(, CowRequest) inflight_reqs;
+ #if defined(HAVE_HOST_BLOCK_DEVICE)
+ #include <paths.h>
-     HBitmap *copy_bitmap;
+ #include <sys/param.h>
-+    bool use_copy_range;
++#include <sys/mount.h>
-+    int64_t copy_range_size;
+ #include <IOKit/IOKitLib.h>
- } BackupBlockJob;
+ #include <IOKit/IOBSD.h>
+ #include <IOKit/storage/IOMediaBSDClient.h>
- static const BlockJobDriver backup_job_driver;
+@@ -XXX,XX +XXX,XX @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
-@@ -XXX,XX +XXX,XX @@ static void cow_request_end(CowRequest *req)
+         return;
-     qemu_co_queue_restart_all(&req->wait_queue);
+     }
 +#if defined(__APPLE__) && (__MACH__)
 +    struct statfs buf;
 +
 +    if (!fstatfs(s->fd, &buf)) {
 +        bs->bl.opt_transfer = buf.f_iosize;
 +        bs->bl.pdiscard_alignment = buf.f_bsize;
 +    }
 +#endif
 +
      if (bs->sg || S_ISBLK(st.st_mode)) {
          int ret = hdev_get_max_hw_transfer(s->fd, &st);
@@ -XXX,XX +XXX,XX @@ out:
      }
  }
-+/* Copy range to target with a bounce buffer and return the bytes copied. If
++#if defined(CONFIG_FALLOCATE) || defined(BLKZEROOUT) || defined(BLKDISCARD)
-+ * error occured, return a negative error number */
+ static int translate_err(int err)
-+static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
+ {
-+                                                      int64_t start,
+     if (err == -ENODEV || err == -ENOSYS || err == -EOPNOTSUPP ||
-+                                                      int64_t end,
+@@ -XXX,XX +XXX,XX @@ static int translate_err(int err)
-+                                                      bool is_write_notifier,
+     }
-+                                                      bool *error_is_read,
+     return err;
-+                                                      void **bounce_buffer)
+ }
-+{
++#endif
-+    int ret;
-+    struct iovec iov;
+ #ifdef CONFIG_FALLOCATE
-+    QEMUIOVector qiov;
+ static int do_fallocate(int fd, int mode, off_t offset, off_t len)
-+    BlockBackend *blk = job->common.blk;
+@@ -XXX,XX +XXX,XX @@ static int handle_aiocb_discard(void *opaque)
-+    int nbytes;
+             }
-+
+         } while (errno == EINTR);
-+    hbitmap_reset(job->copy_bitmap, start / job->cluster_size, 1);
-+    nbytes = MIN(job->cluster_size, job->len - start);
+-        ret = -errno;
-+    if (!*bounce_buffer) {
++        ret = translate_err(-errno);
-+        *bounce_buffer = blk_blockalign(blk, job->cluster_size);
+ #endif
-+    }
+     } else {
-+    iov.iov_base = *bounce_buffer;
+ #ifdef CONFIG_FALLOCATE_PUNCH_HOLE
-+    iov.iov_len = nbytes;
+         ret = do_fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
-+    qemu_iovec_init_external(&qiov, &iov, 1);
+                            aiocb->aio_offset, aiocb->aio_nbytes);
-+
++        ret = translate_err(-errno);
-+    ret = blk_co_preadv(blk, start, qiov.size, &qiov,
++#elif defined(__APPLE__) && (__MACH__)
-+                        is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);
++        fpunchhole_t fpunchhole;
-+    if (ret < 0) {
++        fpunchhole.fp_flags = 0;
-+        trace_backup_do_cow_read_fail(job, start, ret);
++        fpunchhole.reserved = 0;
-+        if (error_is_read) {
++        fpunchhole.fp_offset = aiocb->aio_offset;
-+            *error_is_read = true;
++        fpunchhole.fp_length = aiocb->aio_nbytes;
 +        if (fcntl(s->fd, F_PUNCHHOLE, &fpunchhole) == -1) {
 +            ret = errno == ENODEV ? -ENOTSUP : -errno;
 +        } else {
 +            ret = 0;
 +        }
-+        goto fail;
+ #endif
 +    }
 +
 +    if (qemu_iovec_is_zero(&qiov)) {
 +        ret = blk_co_pwrite_zeroes(job->target, start,
 +                                   qiov.size, BDRV_REQ_MAY_UNMAP);
 +    } else {
 +        ret = blk_co_pwritev(job->target, start,
 +                             qiov.size, &qiov,
 +                             job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0);
 +    }
 +    if (ret < 0) {
 +        trace_backup_do_cow_write_fail(job, start, ret);
 +        if (error_is_read) {
 +            *error_is_read = false;
 +        }
 +        goto fail;
 +    }
 +
 +    return nbytes;
 +fail:
 +    hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1);
 +    return ret;
 +
 +}
 +
 +/* Copy range to target and return the bytes copied. If error occured, return a
 + * negative error number. */
 +static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job,
 +                                                int64_t start,
 +                                                int64_t end,
 +                                                bool is_write_notifier)
 +{
 +    int ret;
 +    int nr_clusters;
 +    BlockBackend *blk = job->common.blk;
 +    int nbytes;
 +
 +    assert(QEMU_IS_ALIGNED(job->copy_range_size, job->cluster_size));
 +    nbytes = MIN(job->copy_range_size, end - start);
 +    nr_clusters = DIV_ROUND_UP(nbytes, job->cluster_size);
 +    hbitmap_reset(job->copy_bitmap, start / job->cluster_size,
 +                  nr_clusters);
 +    ret = blk_co_copy_range(blk, start, job->target, start, nbytes,
 +                            is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);
 +    if (ret < 0) {
 +        trace_backup_do_cow_copy_range_fail(job, start, ret);
 +        hbitmap_set(job->copy_bitmap, start / job->cluster_size,
 +                    nr_clusters);
 +        return ret;
 +    }
 +
 +    return nbytes;
 +}
 +
  static int coroutine_fn backup_do_cow(BackupBlockJob *job,
                                        int64_t offset, uint64_t bytes,
                                        bool *error_is_read,
                                        bool is_write_notifier)
  {
 -    BlockBackend *blk = job->common.blk;
      CowRequest cow_request;
 -    struct iovec iov;
 -    QEMUIOVector bounce_qiov;
 -    void *bounce_buffer = NULL;
      int ret = 0;
      int64_t start, end; /* bytes */
 -    int n; /* bytes */
 +    void *bounce_buffer = NULL;
      qemu_co_rwlock_rdlock(&job->flush_rwlock);
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job,
      wait_for_overlapping_requests(job, start, end);
      cow_request_begin(&cow_request, job, start, end);
 -    for (; start < end; start += job->cluster_size) {
 +    while (start < end) {
          if (!hbitmap_get(job->copy_bitmap, start / job->cluster_size)) {
              trace_backup_do_cow_skip(job, start);
 +            start += job->cluster_size;
              continue; /* already copied */
          }
 -        hbitmap_reset(job->copy_bitmap, start / job->cluster_size, 1);
          trace_backup_do_cow_process(job, start);
 -        n = MIN(job->cluster_size, job->len - start);
 -
 -        if (!bounce_buffer) {
 -            bounce_buffer = blk_blockalign(blk, job->cluster_size);
 -        }
 -        iov.iov_base = bounce_buffer;
 -        iov.iov_len = n;
 -        qemu_iovec_init_external(&bounce_qiov, &iov, 1);
 -
 -        ret = blk_co_preadv(blk, start, bounce_qiov.size, &bounce_qiov,
 -                            is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);
 -        if (ret < 0) {
 -            trace_backup_do_cow_read_fail(job, start, ret);
 -            if (error_is_read) {
 -                *error_is_read = true;
 +        if (job->use_copy_range) {
 +            ret = backup_cow_with_offload(job, start, end, is_write_notifier);
 +            if (ret < 0) {
 +                job->use_copy_range = false;
              }
 -            hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1);
 -            goto out;
          }
 -
 -        if (buffer_is_zero(iov.iov_base, iov.iov_len)) {
 -            ret = blk_co_pwrite_zeroes(job->target, start,
 -                                       bounce_qiov.size, BDRV_REQ_MAY_UNMAP);
 -        } else {
 -            ret = blk_co_pwritev(job->target, start,
 -                                 bounce_qiov.size, &bounce_qiov,
 -                                 job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0);
 +        if (!job->use_copy_range) {
 +            ret = backup_cow_with_bounce_buffer(job, start, end, is_write_notifier,
 +                                                error_is_read, &bounce_buffer);
          }
          if (ret < 0) {
 -            trace_backup_do_cow_write_fail(job, start, ret);
 -            if (error_is_read) {
 -                *error_is_read = false;
 -            }
 -            hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1);
 -            goto out;
 +            break;
          }
          /* Publish progress, guest I/O counts as progress too.  Note that the
           * offset field is an opaque progress value, it is not a disk offset.
           */
 -        job->bytes_read += n;
 -        job_progress_update(&job->common.job, n);
 +        start += ret;
 +        job->bytes_read += ret;
 +        job_progress_update(&job->common.job, ret);
 +        ret = 0;
      }
--out:
+-    ret = translate_err(ret);
-     if (bounce_buffer) {
+     if (ret == -ENOTSUP) {
-         qemu_vfree(bounce_buffer);
+         s->has_discard = false;
      }
-@@ -XXX,XX +XXX,XX @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
-     } else {
-         job->cluster_size = MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
-     }
-+    job->use_copy_range = true;
-+    job->copy_range_size = MIN_NON_ZERO(blk_get_max_transfer(job->common.blk),
-+                                        blk_get_max_transfer(job->target));
-+    job->copy_range_size = MAX(job->cluster_size,
-+                               QEMU_ALIGN_UP(job->copy_range_size,
-+                                             job->cluster_size));
-     /* Required permissions are already taken with target's blk_new() */
-     block_job_add_bdrv(&job->common, "target", target, 0, BLK_PERM_ALL,
-diff --git a/block/trace-events b/block/trace-events
-index XXXXXXX..XXXXXXX 100644
---- a/block/trace-events
-+++ b/block/trace-events
-@@ -XXX,XX +XXX,XX @@ backup_do_cow_skip(void *job, int64_t start) "job %p start %"PRId64
- backup_do_cow_process(void *job, int64_t start) "job %p start %"PRId64
- backup_do_cow_read_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d"
- backup_do_cow_write_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d"
-+backup_do_cow_copy_range_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d"
- # blockdev.c
- qmp_block_job_cancel(void *job) "job %p"
 --
-.17.1
+.31.1

-New patch
+[PULL 4/5] block: Add backend_defaults property
+From: Akihiko Odaki <akihiko.odaki@gmail.com>
 backend_defaults property allow users to control if default block
 properties should be decided with backend information.
 If it is off, any backend information will be discarded, which is
 suitable if you plan to perform live migration to a different disk backend.
 If it is on, a block device may utilize backend information more
 aggressively.
 By default, it is auto, which uses backend information for block
 sizes and ignores the others, which is consistent with the older
 versions.
 Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
 Message-id: 20210705130458.97642-2-akihiko.odaki@gmail.com
 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 ---
  include/hw/block/block.h   |  3 +++
  hw/block/block.c           | 42 ++++++++++++++++++++++++++++++++++----
  tests/qemu-iotests/172.out | 38 ++++++++++++++++++++++++++++++++++
 files changed, 79 insertions(+), 4 deletions(-)
 diff --git a/include/hw/block/block.h b/include/hw/block/block.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/hw/block/block.h
 +++ b/include/hw/block/block.h
@@ -XXX,XX +XXX,XX @@
  typedef struct BlockConf {
      BlockBackend *blk;
 +    OnOffAuto backend_defaults;
      uint32_t physical_block_size;
      uint32_t logical_block_size;
      uint32_t min_io_size;
@@ -XXX,XX +XXX,XX @@ static inline unsigned int get_physical_block_exp(BlockConf *conf)
  }
  #define DEFINE_BLOCK_PROPERTIES_BASE(_state, _conf)                     \
 +    DEFINE_PROP_ON_OFF_AUTO("backend_defaults", _state,                 \
 +                            _conf.backend_defaults, ON_OFF_AUTO_AUTO),  \
      DEFINE_PROP_BLOCKSIZE("logical_block_size", _state,                 \
                            _conf.logical_block_size),                    \
      DEFINE_PROP_BLOCKSIZE("physical_block_size", _state,                \
 diff --git a/hw/block/block.c b/hw/block/block.c
 index XXXXXXX..XXXXXXX 100644
 --- a/hw/block/block.c
 +++ b/hw/block/block.c
@@ -XXX,XX +XXX,XX @@ bool blkconf_blocksizes(BlockConf *conf, Error **errp)
  {
      BlockBackend *blk = conf->blk;
      BlockSizes blocksizes;
 -    int backend_ret;
 +    BlockDriverState *bs;
 +    bool use_blocksizes;
 +    bool use_bs;
 +
 +    switch (conf->backend_defaults) {
 +    case ON_OFF_AUTO_AUTO:
 +        use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes);
 +        use_bs = false;
 +        break;
 +
 +    case ON_OFF_AUTO_ON:
 +        use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes);
 +        bs = blk_bs(blk);
 +        use_bs = bs;
 +        break;
 +
 +    case ON_OFF_AUTO_OFF:
 +        use_blocksizes = false;
 +        use_bs = false;
 +        break;
 +
 +    default:
 +        abort();
 +    }
 -    backend_ret = blk_probe_blocksizes(blk, &blocksizes);
      /* fill in detected values if they are not defined via qemu command line */
      if (!conf->physical_block_size) {
 -        if (!backend_ret) {
 +        if (use_blocksizes) {
             conf->physical_block_size = blocksizes.phys;
          } else {
              conf->physical_block_size = BDRV_SECTOR_SIZE;
          }
      }
      if (!conf->logical_block_size) {
 -        if (!backend_ret) {
 +        if (use_blocksizes) {
              conf->logical_block_size = blocksizes.log;
          } else {
              conf->logical_block_size = BDRV_SECTOR_SIZE;
          }
      }
 +    if (use_bs) {
 +        if (!conf->opt_io_size) {
 +            conf->opt_io_size = bs->bl.opt_transfer;
 +        }
 +        if (conf->discard_granularity == -1) {
 +            if (bs->bl.pdiscard_alignment) {
 +                conf->discard_granularity = bs->bl.pdiscard_alignment;
 +            } else if (bs->bl.request_alignment != 1) {
 +                conf->discard_granularity = bs->bl.request_alignment;
 +            }
 +        }
 +    }
      if (conf->logical_block_size > conf->physical_block_size) {
          error_setg(errp,
 diff --git a/tests/qemu-iotests/172.out b/tests/qemu-iotests/172.out
 index XXXXXXX..XXXXXXX 100644
 --- a/tests/qemu-iotests/172.out
 +++ b/tests/qemu-iotests/172.out
@@ -XXX,XX +XXX,XX @@ Testing:
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "floppy1"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -fdb TEST_DIR/t.qcow2.2
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "floppy1"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -fdb TEST_DIR/t.qcow2.2
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "floppy1"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2,index=1
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "floppy1"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2,index=1
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=floppy,file=TEST_DIR/t
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "floppy1"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=floppy,file=TEST_DIR/t
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,unit=1
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qco
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "none1"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qco
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "floppy1"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "floppy1"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
                dev: floppy, id ""
                  unit = 1 (0x1)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "floppy0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -global floppy.drive=none0 -device
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -device floppy
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = ""
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -device floppy,drive-type=120
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = ""
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -device floppy,drive-type=144
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = ""
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -device floppy,drive-type=288
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = ""
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,drive-t
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,drive-t
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,logical
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,physica
                dev: floppy, id ""
                  unit = 0 (0x0)
                  drive = "none0"
 +                backend_defaults = "auto"
                  logical_block_size = 512 (512 B)
                  physical_block_size = 512 (512 B)
                  min_io_size = 0 (0 B)
 --
 .31.1

-[Qemu-devel] [PULL 2/3] block: Honour BDRV_REQ_NO_SERIALISING in copy range
+[PULL 5/5] block/io: Merge discard request alignments
-From: Fam Zheng <famz@redhat.com>
+From: Akihiko Odaki <akihiko.odaki@gmail.com>
-This semantics is needed by drive-backup so implement it before using
+Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
-this API there.
+Message-id: 20210705130458.97642-3-akihiko.odaki@gmail.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
 Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
 Signed-off-by: Fam Zheng <famz@redhat.com>
 Message-id: 20180703023758.14422-3-famz@redhat.com
 Signed-off-by: Jeff Cody <jcody@redhat.com>
 ---
- block/io.c            | 6 ++++--
+ block/io.c | 2 ++
- include/block/block.h | 5 +++--
+file changed, 2 insertions(+)
 files changed, 7 insertions(+), 4 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 @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,
+@@ -XXX,XX +XXX,XX @@ void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll)
-     tracked_request_begin(&dst_req, dst->bs, dst_offset,
-                           bytes, BDRV_TRACKED_WRITE);
+ static void bdrv_merge_limits(BlockLimits *dst, const BlockLimits *src)
+ {
--    wait_serialising_requests(&src_req);
++    dst->pdiscard_alignment = MAX(dst->pdiscard_alignment,
--    wait_serialising_requests(&dst_req);
++                                  src->pdiscard_alignment);
-+    if (!(flags & BDRV_REQ_NO_SERIALISING)) {
+     dst->opt_transfer = MAX(dst->opt_transfer, src->opt_transfer);
-+        wait_serialising_requests(&src_req);
+     dst->max_transfer = MIN_NON_ZERO(dst->max_transfer, src->max_transfer);
-+        wait_serialising_requests(&dst_req);
+     dst->max_hw_transfer = MIN_NON_ZERO(dst->max_hw_transfer,
 +    }
      if (recurse_src) {
          ret = src->bs->drv->bdrv_co_copy_range_from(src->bs,
                                                      src, src_offset,
 diff --git a/include/block/block.h b/include/block/block.h
 index XXXXXXX..XXXXXXX 100644
 --- a/include/block/block.h
 +++ b/include/block/block.h
@@ -XXX,XX +XXX,XX @@ void bdrv_unregister_buf(BlockDriverState *bs, void *host);
   * @dst: Destination child to copy data to
   * @dst_offset: offset in @dst image to write data
   * @bytes: number of bytes to copy
 - * @flags: request flags. Must be one of:
 - *         0 - actually read data from src;
 + * @flags: request flags. Supported flags:
   *         BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
   *                               write on @dst as if bdrv_co_pwrite_zeroes is
   *                               called. Used to simplify caller code, or
   *                               during BlockDriver.bdrv_co_copy_range_from()
   *                               recursion.
 + *         BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
 + *                                   requests currently in flight.
   *
   * Returns: 0 if succeeded; negative error code if failed.
   **/
 --
-.17.1
+.31.1

From: Fam Zheng <famz@redhat.com>

src may be NULL if BDRV_REQ_ZERO_WRITE flag is set, in this case only
check dst and dst->bs. This bug was introduced when moving in the
request tracking code from bdrv_co_copy_range, in 37aec7d75eb.

This especially fixes the possible segfault when initializing src_bs
with a NULL src.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 20180703023758.14422-2-famz@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 block/io.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 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 @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,
                                                     bool recurse_src)
 {
     BdrvTrackedRequest src_req, dst_req;
-    BlockDriverState *src_bs = src->bs;
-    BlockDriverState *dst_bs = dst->bs;
     int ret;
 
-    if (!src || !dst || !src->bs || !dst->bs) {
+    if (!dst || !dst->bs) {
         return -ENOMEDIUM;
     }
-    ret = bdrv_check_byte_request(src->bs, src_offset, bytes);
-    if (ret) {
-        return ret;
-    }
-
     ret = bdrv_check_byte_request(dst->bs, dst_offset, bytes);
     if (ret) {
         return ret;
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,
         return bdrv_co_pwrite_zeroes(dst, dst_offset, bytes, flags);
     }
 
+    if (!src || !src->bs) {
+        return -ENOMEDIUM;
+    }
+    ret = bdrv_check_byte_request(src->bs, src_offset, bytes);
+    if (ret) {
+        return ret;
+    }
+
     if (!src->bs->drv->bdrv_co_copy_range_from
         || !dst->bs->drv->bdrv_co_copy_range_to
         || src->bs->encrypted || dst->bs->encrypted) {
         return -ENOTSUP;
     }
-    bdrv_inc_in_flight(src_bs);
-    bdrv_inc_in_flight(dst_bs);
-    tracked_request_begin(&src_req, src_bs, src_offset,
+    bdrv_inc_in_flight(src->bs);
+    bdrv_inc_in_flight(dst->bs);
+    tracked_request_begin(&src_req, src->bs, src_offset,
                           bytes, BDRV_TRACKED_READ);
-    tracked_request_begin(&dst_req, dst_bs, dst_offset,
+    tracked_request_begin(&dst_req, dst->bs, dst_offset,
                           bytes, BDRV_TRACKED_WRITE);
 
     wait_serialising_requests(&src_req);
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,
     }
     tracked_request_end(&src_req);
     tracked_request_end(&dst_req);
-    bdrv_dec_in_flight(src_bs);
-    bdrv_dec_in_flight(dst_bs);
+    bdrv_dec_in_flight(src->bs);
+    bdrv_dec_in_flight(dst->bs);
     return ret;
 }
 
-- 
2.17.1

From: Fam Zheng <famz@redhat.com>

This semantics is needed by drive-backup so implement it before using
this API there.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 20180703023758.14422-3-famz@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 block/io.c            | 6 ++++--
 include/block/block.h | 5 +++--
 2 files changed, 7 insertions(+), 4 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 @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,
     tracked_request_begin(&dst_req, dst->bs, dst_offset,
                           bytes, BDRV_TRACKED_WRITE);
 
-    wait_serialising_requests(&src_req);
-    wait_serialising_requests(&dst_req);
+    if (!(flags & BDRV_REQ_NO_SERIALISING)) {
+        wait_serialising_requests(&src_req);
+        wait_serialising_requests(&dst_req);
+    }
     if (recurse_src) {
         ret = src->bs->drv->bdrv_co_copy_range_from(src->bs,
                                                     src, src_offset,
diff --git a/include/block/block.h b/include/block/block.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -XXX,XX +XXX,XX @@ void bdrv_unregister_buf(BlockDriverState *bs, void *host);
  * @dst: Destination child to copy data to
  * @dst_offset: offset in @dst image to write data
  * @bytes: number of bytes to copy
- * @flags: request flags. Must be one of:
- *         0 - actually read data from src;
+ * @flags: request flags. Supported flags:
  *         BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero
  *                               write on @dst as if bdrv_co_pwrite_zeroes is
  *                               called. Used to simplify caller code, or
  *                               during BlockDriver.bdrv_co_copy_range_from()
  *                               recursion.
+ *         BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping
+ *                                   requests currently in flight.
  *
  * Returns: 0 if succeeded; negative error code if failed.
  **/
-- 
2.17.1

From: Fam Zheng <famz@redhat.com>

The implementation is similar to the 'qemu-img convert'. In the
beginning of the job, offloaded copy is attempted. If it fails, further
I/O will go through the existing bounce buffer code path.

Then, as Kevin pointed out, both this and qemu-img convert can benefit
from a local check if one request fails because of, for example, the
offset is beyond EOF, but another may well be accepted by the protocol
layer. This will be implemented separately.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 20180703023758.14422-4-famz@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
---
 block/backup.c     | 150 ++++++++++++++++++++++++++++++++-------------
 block/trace-events |   1 +
 2 files changed, 110 insertions(+), 41 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 @@ typedef struct BackupBlockJob {
     QLIST_HEAD(, CowRequest) inflight_reqs;
 
     HBitmap *copy_bitmap;
+    bool use_copy_range;
+    int64_t copy_range_size;
 } BackupBlockJob;
 
 static const BlockJobDriver backup_job_driver;
@@ -XXX,XX +XXX,XX @@ static void cow_request_end(CowRequest *req)
     qemu_co_queue_restart_all(&req->wait_queue);
 }
 
+/* Copy range to target with a bounce buffer and return the bytes copied. If
+ * error occured, return a negative error number */
+static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
+                                                      int64_t start,
+                                                      int64_t end,
+                                                      bool is_write_notifier,
+                                                      bool *error_is_read,
+                                                      void **bounce_buffer)
+{
+    int ret;
+    struct iovec iov;
+    QEMUIOVector qiov;
+    BlockBackend *blk = job->common.blk;
+    int nbytes;
+
+    hbitmap_reset(job->copy_bitmap, start / job->cluster_size, 1);
+    nbytes = MIN(job->cluster_size, job->len - start);
+    if (!*bounce_buffer) {
+        *bounce_buffer = blk_blockalign(blk, job->cluster_size);
+    }
+    iov.iov_base = *bounce_buffer;
+    iov.iov_len = nbytes;
+    qemu_iovec_init_external(&qiov, &iov, 1);
+
+    ret = blk_co_preadv(blk, start, qiov.size, &qiov,
+                        is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);
+    if (ret < 0) {
+        trace_backup_do_cow_read_fail(job, start, ret);
+        if (error_is_read) {
+            *error_is_read = true;
+        }
+        goto fail;
+    }
+
+    if (qemu_iovec_is_zero(&qiov)) {
+        ret = blk_co_pwrite_zeroes(job->target, start,
+                                   qiov.size, BDRV_REQ_MAY_UNMAP);
+    } else {
+        ret = blk_co_pwritev(job->target, start,
+                             qiov.size, &qiov,
+                             job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0);
+    }
+    if (ret < 0) {
+        trace_backup_do_cow_write_fail(job, start, ret);
+        if (error_is_read) {
+            *error_is_read = false;
+        }
+        goto fail;
+    }
+
+    return nbytes;
+fail:
+    hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1);
+    return ret;
+
+}
+
+/* Copy range to target and return the bytes copied. If error occured, return a
+ * negative error number. */
+static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job,
+                                                int64_t start,
+                                                int64_t end,
+                                                bool is_write_notifier)
+{
+    int ret;
+    int nr_clusters;
+    BlockBackend *blk = job->common.blk;
+    int nbytes;
+
+    assert(QEMU_IS_ALIGNED(job->copy_range_size, job->cluster_size));
+    nbytes = MIN(job->copy_range_size, end - start);
+    nr_clusters = DIV_ROUND_UP(nbytes, job->cluster_size);
+    hbitmap_reset(job->copy_bitmap, start / job->cluster_size,
+                  nr_clusters);
+    ret = blk_co_copy_range(blk, start, job->target, start, nbytes,
+                            is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);
+    if (ret < 0) {
+        trace_backup_do_cow_copy_range_fail(job, start, ret);
+        hbitmap_set(job->copy_bitmap, start / job->cluster_size,
+                    nr_clusters);
+        return ret;
+    }
+
+    return nbytes;
+}
+
 static int coroutine_fn backup_do_cow(BackupBlockJob *job,
                                       int64_t offset, uint64_t bytes,
                                       bool *error_is_read,
                                       bool is_write_notifier)
 {
-    BlockBackend *blk = job->common.blk;
     CowRequest cow_request;
-    struct iovec iov;
-    QEMUIOVector bounce_qiov;
-    void *bounce_buffer = NULL;
     int ret = 0;
     int64_t start, end; /* bytes */
-    int n; /* bytes */
+    void *bounce_buffer = NULL;
 
     qemu_co_rwlock_rdlock(&job->flush_rwlock);
 
@@ -XXX,XX +XXX,XX @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job,
     wait_for_overlapping_requests(job, start, end);
     cow_request_begin(&cow_request, job, start, end);
 
-    for (; start < end; start += job->cluster_size) {
+    while (start < end) {
         if (!hbitmap_get(job->copy_bitmap, start / job->cluster_size)) {
             trace_backup_do_cow_skip(job, start);
+            start += job->cluster_size;
             continue; /* already copied */
         }
-        hbitmap_reset(job->copy_bitmap, start / job->cluster_size, 1);
 
         trace_backup_do_cow_process(job, start);
 
-        n = MIN(job->cluster_size, job->len - start);
-
-        if (!bounce_buffer) {
-            bounce_buffer = blk_blockalign(blk, job->cluster_size);
-        }
-        iov.iov_base = bounce_buffer;
-        iov.iov_len = n;
-        qemu_iovec_init_external(&bounce_qiov, &iov, 1);
-
-        ret = blk_co_preadv(blk, start, bounce_qiov.size, &bounce_qiov,
-                            is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);
-        if (ret < 0) {
-            trace_backup_do_cow_read_fail(job, start, ret);
-            if (error_is_read) {
-                *error_is_read = true;
+        if (job->use_copy_range) {
+            ret = backup_cow_with_offload(job, start, end, is_write_notifier);
+            if (ret < 0) {
+                job->use_copy_range = false;
             }
-            hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1);
-            goto out;
         }
-
-        if (buffer_is_zero(iov.iov_base, iov.iov_len)) {
-            ret = blk_co_pwrite_zeroes(job->target, start,
-                                       bounce_qiov.size, BDRV_REQ_MAY_UNMAP);
-        } else {
-            ret = blk_co_pwritev(job->target, start,
-                                 bounce_qiov.size, &bounce_qiov,
-                                 job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0);
+        if (!job->use_copy_range) {
+            ret = backup_cow_with_bounce_buffer(job, start, end, is_write_notifier,
+                                                error_is_read, &bounce_buffer);
         }
         if (ret < 0) {
-            trace_backup_do_cow_write_fail(job, start, ret);
-            if (error_is_read) {
-                *error_is_read = false;
-            }
-            hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1);
-            goto out;
+            break;
         }
 
         /* Publish progress, guest I/O counts as progress too.  Note that the
          * offset field is an opaque progress value, it is not a disk offset.
          */
-        job->bytes_read += n;
-        job_progress_update(&job->common.job, n);
+        start += ret;
+        job->bytes_read += ret;
+        job_progress_update(&job->common.job, ret);
+        ret = 0;
     }
 
-out:
     if (bounce_buffer) {
         qemu_vfree(bounce_buffer);
     }
@@ -XXX,XX +XXX,XX @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
     } else {
         job->cluster_size = MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
     }
+    job->use_copy_range = true;
+    job->copy_range_size = MIN_NON_ZERO(blk_get_max_transfer(job->common.blk),
+                                        blk_get_max_transfer(job->target));
+    job->copy_range_size = MAX(job->cluster_size,
+                               QEMU_ALIGN_UP(job->copy_range_size,
+                                             job->cluster_size));
 
     /* Required permissions are already taken with target's blk_new() */
     block_job_add_bdrv(&job->common, "target", target, 0, BLK_PERM_ALL,
diff --git a/block/trace-events b/block/trace-events
index XXXXXXX..XXXXXXX 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -XXX,XX +XXX,XX @@ backup_do_cow_skip(void *job, int64_t start) "job %p start %"PRId64
 backup_do_cow_process(void *job, int64_t start) "job %p start %"PRId64
 backup_do_cow_read_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d"
 backup_do_cow_write_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d"
+backup_do_cow_copy_range_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d"
 
 # blockdev.c
 qmp_block_job_cancel(void *job) "job %p"
-- 
2.17.1

The following changes since commit 711c0418c8c1ce3a24346f058b001c4c5a2f0f81:

Merge remote-tracking branch 'remotes/philmd/tags/mips-20210702' into staging (2021-07-04 14:04:12 +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 9f460c64e13897117f35ffb61f6f5e0102cabc70:

block/io: Merge discard request alignments (2021-07-06 14:28:55 +0100)

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

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

Akihiko Odaki (3):
  block/file-posix: Optimize for macOS
  block: Add backend_defaults property
  block/io: Merge discard request alignments

Stefan Hajnoczi (2):
  util/async: add a human-readable name to BHs for debugging
  util/async: print leaked BH name when AioContext finalizes

-- 
2.31.1

It can be difficult to debug issues with BHs in production environments.
Although BHs can usually be identified by looking up their ->cb()
function pointer, this requires debug information for the program. It is
also not possible to print human-readable diagnostics about BHs because
they have no identifier.

This patch adds a name to each BH. The name is not unique per instance
but differentiates between cb() functions, which is usually enough. It's
done by changing aio_bh_new() and friends to macros that stringify cb.

The next patch will use the name field when reporting leaked BHs.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210414200247.917496-2-stefanha@redhat.com>
---
 include/block/aio.h            | 31 ++++++++++++++++++++++++++++---
 include/qemu/main-loop.h       |  4 +++-
 tests/unit/ptimer-test-stubs.c |  2 +-
 util/async.c                   |  9 +++++++--
 util/main-loop.c               |  4 ++--
 5 files changed, 41 insertions(+), 9 deletions(-)

diff --git a/include/block/aio.h b/include/block/aio.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -XXX,XX +XXX,XX @@ void aio_context_acquire(AioContext *ctx);
 /* Relinquish ownership of the AioContext. */
 void aio_context_release(AioContext *ctx);
 
+/**
+ * aio_bh_schedule_oneshot_full: Allocate a new bottom half structure that will
+ * run only once and as soon as possible.
+ *
+ * @name: A human-readable identifier for debugging purposes.
+ */
+void aio_bh_schedule_oneshot_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
+                                  const char *name);
+
 /**
  * aio_bh_schedule_oneshot: Allocate a new bottom half structure that will run
  * only once and as soon as possible.
+ *
+ * A convenience wrapper for aio_bh_schedule_oneshot_full() that uses cb as the
+ * name string.
  */
-void aio_bh_schedule_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque);
+#define aio_bh_schedule_oneshot(ctx, cb, opaque) \
+    aio_bh_schedule_oneshot_full((ctx), (cb), (opaque), (stringify(cb)))
 
 /**
- * aio_bh_new: Allocate a new bottom half structure.
+ * aio_bh_new_full: Allocate a new bottom half structure.
  *
  * Bottom halves are lightweight callbacks whose invocation is guaranteed
  * to be wait-free, thread-safe and signal-safe.  The #QEMUBH structure
  * is opaque and must be allocated prior to its use.
+ *
+ * @name: A human-readable identifier for debugging purposes.
  */
-QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque);
+QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
+                        const char *name);
+
+/**
+ * aio_bh_new: Allocate a new bottom half structure
+ *
+ * A convenience wrapper for aio_bh_new_full() that uses the cb as the name
+ * string.
+ */
+#define aio_bh_new(ctx, cb, opaque) \
+    aio_bh_new_full((ctx), (cb), (opaque), (stringify(cb)))
 
 /**
  * aio_notify: Force processing of pending events.
diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h
index XXXXXXX..XXXXXXX 100644
--- a/include/qemu/main-loop.h
+++ b/include/qemu/main-loop.h
@@ -XXX,XX +XXX,XX @@ void qemu_cond_timedwait_iothread(QemuCond *cond, int ms);
 
 void qemu_fd_register(int fd);
 
-QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque);
+#define qemu_bh_new(cb, opaque) \
+    qemu_bh_new_full((cb), (opaque), (stringify(cb)))
+QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name);
 void qemu_bh_schedule_idle(QEMUBH *bh);
 
 enum {
diff --git a/tests/unit/ptimer-test-stubs.c b/tests/unit/ptimer-test-stubs.c
index XXXXXXX..XXXXXXX 100644
--- a/tests/unit/ptimer-test-stubs.c
+++ b/tests/unit/ptimer-test-stubs.c
@@ -XXX,XX +XXX,XX @@ int64_t qemu_clock_deadline_ns_all(QEMUClockType type, int attr_mask)
     return deadline;
 }
 
-QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
+QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name)
 {
     QEMUBH *bh = g_new(QEMUBH, 1);
 
diff --git a/util/async.c b/util/async.c
index XXXXXXX..XXXXXXX 100644
--- a/util/async.c
+++ b/util/async.c
@@ -XXX,XX +XXX,XX @@ enum {
 
 struct QEMUBH {
     AioContext *ctx;
+    const char *name;
     QEMUBHFunc *cb;
     void *opaque;
     QSLIST_ENTRY(QEMUBH) next;
@@ -XXX,XX +XXX,XX @@ static QEMUBH *aio_bh_dequeue(BHList *head, unsigned *flags)
     return bh;
 }
 
-void aio_bh_schedule_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
+void aio_bh_schedule_oneshot_full(AioContext *ctx, QEMUBHFunc *cb,
+                                  void *opaque, const char *name)
 {
     QEMUBH *bh;
     bh = g_new(QEMUBH, 1);
@@ -XXX,XX +XXX,XX @@ void aio_bh_schedule_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
         .ctx = ctx,
         .cb = cb,
         .opaque = opaque,
+        .name = name,
     };
     aio_bh_enqueue(bh, BH_SCHEDULED | BH_ONESHOT);
 }
 
-QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
+QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
+                        const char *name)
 {
     QEMUBH *bh;
     bh = g_new(QEMUBH, 1);
@@ -XXX,XX +XXX,XX @@ QEMUBH *aio_bh_new(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
         .ctx = ctx,
         .cb = cb,
         .opaque = opaque,
+        .name = name,
     };
     return bh;
 }
diff --git a/util/main-loop.c b/util/main-loop.c
index XXXXXXX..XXXXXXX 100644
--- a/util/main-loop.c
+++ b/util/main-loop.c
@@ -XXX,XX +XXX,XX @@ void main_loop_wait(int nonblocking)
 
 /* Functions to operate on the main QEMU AioContext.  */
 
-QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
+QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name)
 {
-    return aio_bh_new(qemu_aio_context, cb, opaque);
+    return aio_bh_new_full(qemu_aio_context, cb, opaque, name);
 }
 
 /*
-- 
2.31.1

BHs must be deleted before the AioContext is finalized. If not, it's a
bug and probably indicates that some part of the program still expects
the BH to run in the future. That can lead to memory leaks, inconsistent
state, or just hangs.

Unfortunately the assert(flags & BH_DELETED) call in aio_ctx_finalize()
is difficult to debug because the assertion failure contains no
information about the BH!

Use the QEMUBH name field added in the previous patch to show a useful
error when a leaked BH is detected.

Suggested-by: Eric Ernst <eric.g.ernst@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20210414200247.917496-3-stefanha@redhat.com>
---
 util/async.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/util/async.c b/util/async.c
index XXXXXXX..XXXXXXX 100644
--- a/util/async.c
+++ b/util/async.c
@@ -XXX,XX +XXX,XX @@ aio_ctx_finalize(GSource     *source)
     assert(QSIMPLEQ_EMPTY(&ctx->bh_slice_list));
 
     while ((bh = aio_bh_dequeue(&ctx->bh_list, &flags))) {
-        /* qemu_bh_delete() must have been called on BHs in this AioContext */
-        assert(flags & BH_DELETED);
+        /*
+         * qemu_bh_delete() must have been called on BHs in this AioContext. In
+         * many cases memory leaks, hangs, or inconsistent state occur when a
+         * BH is leaked because something still expects it to run.
+         *
+         * If you hit this, fix the lifecycle of the BH so that
+         * qemu_bh_delete() and any associated cleanup is called before the
+         * AioContext is finalized.
+         */
+        if (unlikely(!(flags & BH_DELETED))) {
+            fprintf(stderr, "%s: BH '%s' leaked, aborting...\n",
+                    __func__, bh->name);
+            abort();
+        }
 
         g_free(bh);
     }
-- 
2.31.1

From: Akihiko Odaki <akihiko.odaki@gmail.com>

This commit introduces "punch hole" operation and optimizes transfer
block size for macOS.

Thanks to Konstantin Nazarov for detailed analysis of a flaw in an
old version of this change:
https://gist.github.com/akihikodaki/87df4149e7ca87f18dc56807ec5a1bc5#gistcomment-3654667

Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Message-id: 20210705130458.97642-1-akihiko.odaki@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/file-posix.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index XXXXXXX..XXXXXXX 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -XXX,XX +XXX,XX @@
 #if defined(HAVE_HOST_BLOCK_DEVICE)
 #include <paths.h>
 #include <sys/param.h>
+#include <sys/mount.h>
 #include <IOKit/IOKitLib.h>
 #include <IOKit/IOBSD.h>
 #include <IOKit/storage/IOMediaBSDClient.h>
@@ -XXX,XX +XXX,XX @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
         return;
     }
 
+#if defined(__APPLE__) && (__MACH__)
+    struct statfs buf;
+
+    if (!fstatfs(s->fd, &buf)) {
+        bs->bl.opt_transfer = buf.f_iosize;
+        bs->bl.pdiscard_alignment = buf.f_bsize;
+    }
+#endif
+
     if (bs->sg || S_ISBLK(st.st_mode)) {
         int ret = hdev_get_max_hw_transfer(s->fd, &st);
 
@@ -XXX,XX +XXX,XX @@ out:
     }
 }
 
+#if defined(CONFIG_FALLOCATE) || defined(BLKZEROOUT) || defined(BLKDISCARD)
 static int translate_err(int err)
 {
     if (err == -ENODEV || err == -ENOSYS || err == -EOPNOTSUPP ||
@@ -XXX,XX +XXX,XX @@ static int translate_err(int err)
     }
     return err;
 }
+#endif
 
 #ifdef CONFIG_FALLOCATE
 static int do_fallocate(int fd, int mode, off_t offset, off_t len)
@@ -XXX,XX +XXX,XX @@ static int handle_aiocb_discard(void *opaque)
             }
         } while (errno == EINTR);
 
-        ret = -errno;
+        ret = translate_err(-errno);
 #endif
     } else {
 #ifdef CONFIG_FALLOCATE_PUNCH_HOLE
         ret = do_fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
                            aiocb->aio_offset, aiocb->aio_nbytes);
+        ret = translate_err(-errno);
+#elif defined(__APPLE__) && (__MACH__)
+        fpunchhole_t fpunchhole;
+        fpunchhole.fp_flags = 0;
+        fpunchhole.reserved = 0;
+        fpunchhole.fp_offset = aiocb->aio_offset;
+        fpunchhole.fp_length = aiocb->aio_nbytes;
+        if (fcntl(s->fd, F_PUNCHHOLE, &fpunchhole) == -1) {
+            ret = errno == ENODEV ? -ENOTSUP : -errno;
+        } else {
+            ret = 0;
+        }
 #endif
     }
 
-    ret = translate_err(ret);
     if (ret == -ENOTSUP) {
         s->has_discard = false;
     }
-- 
2.31.1

From: Akihiko Odaki <akihiko.odaki@gmail.com>

backend_defaults property allow users to control if default block
properties should be decided with backend information.

If it is off, any backend information will be discarded, which is
suitable if you plan to perform live migration to a different disk backend.

If it is on, a block device may utilize backend information more
aggressively.

By default, it is auto, which uses backend information for block
sizes and ignores the others, which is consistent with the older
versions.

Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Message-id: 20210705130458.97642-2-akihiko.odaki@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/hw/block/block.h   |  3 +++
 hw/block/block.c           | 42 ++++++++++++++++++++++++++++++++++----
 tests/qemu-iotests/172.out | 38 ++++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+), 4 deletions(-)

diff --git a/include/hw/block/block.h b/include/hw/block/block.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/block/block.h
+++ b/include/hw/block/block.h
@@ -XXX,XX +XXX,XX @@
 
 typedef struct BlockConf {
     BlockBackend *blk;
+    OnOffAuto backend_defaults;
     uint32_t physical_block_size;
     uint32_t logical_block_size;
     uint32_t min_io_size;
@@ -XXX,XX +XXX,XX @@ static inline unsigned int get_physical_block_exp(BlockConf *conf)
 }
 
 #define DEFINE_BLOCK_PROPERTIES_BASE(_state, _conf)                     \
+    DEFINE_PROP_ON_OFF_AUTO("backend_defaults", _state,                 \
+                            _conf.backend_defaults, ON_OFF_AUTO_AUTO),  \
     DEFINE_PROP_BLOCKSIZE("logical_block_size", _state,                 \
                           _conf.logical_block_size),                    \
     DEFINE_PROP_BLOCKSIZE("physical_block_size", _state,                \
diff --git a/hw/block/block.c b/hw/block/block.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/block/block.c
+++ b/hw/block/block.c
@@ -XXX,XX +XXX,XX @@ bool blkconf_blocksizes(BlockConf *conf, Error **errp)
 {
     BlockBackend *blk = conf->blk;
     BlockSizes blocksizes;
-    int backend_ret;
+    BlockDriverState *bs;
+    bool use_blocksizes;
+    bool use_bs;
+
+    switch (conf->backend_defaults) {
+    case ON_OFF_AUTO_AUTO:
+        use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes);
+        use_bs = false;
+        break;
+
+    case ON_OFF_AUTO_ON:
+        use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes);
+        bs = blk_bs(blk);
+        use_bs = bs;
+        break;
+
+    case ON_OFF_AUTO_OFF:
+        use_blocksizes = false;
+        use_bs = false;
+        break;
+
+    default:
+        abort();
+    }
 
-    backend_ret = blk_probe_blocksizes(blk, &blocksizes);
     /* fill in detected values if they are not defined via qemu command line */
     if (!conf->physical_block_size) {
-        if (!backend_ret) {
+        if (use_blocksizes) {
            conf->physical_block_size = blocksizes.phys;
         } else {
             conf->physical_block_size = BDRV_SECTOR_SIZE;
         }
     }
     if (!conf->logical_block_size) {
-        if (!backend_ret) {
+        if (use_blocksizes) {
             conf->logical_block_size = blocksizes.log;
         } else {
             conf->logical_block_size = BDRV_SECTOR_SIZE;
         }
     }
+    if (use_bs) {
+        if (!conf->opt_io_size) {
+            conf->opt_io_size = bs->bl.opt_transfer;
+        }
+        if (conf->discard_granularity == -1) {
+            if (bs->bl.pdiscard_alignment) {
+                conf->discard_granularity = bs->bl.pdiscard_alignment;
+            } else if (bs->bl.request_alignment != 1) {
+                conf->discard_granularity = bs->bl.request_alignment;
+            }
+        }
+    }
 
     if (conf->logical_block_size > conf->physical_block_size) {
         error_setg(errp,
diff --git a/tests/qemu-iotests/172.out b/tests/qemu-iotests/172.out
index XXXXXXX..XXXXXXX 100644
--- a/tests/qemu-iotests/172.out
+++ b/tests/qemu-iotests/172.out
@@ -XXX,XX +XXX,XX @@ Testing:
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "floppy1"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -fdb TEST_DIR/t.qcow2.2
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "floppy1"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -fdb TEST_DIR/t.qcow2.2
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "floppy1"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2,index=1
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "floppy1"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2,index=1
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=floppy,file=TEST_DIR/t
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "floppy1"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=floppy,file=TEST_DIR/t
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,unit=1
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qco
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "none1"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qco
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "floppy1"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "floppy1"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
               dev: floppy, id ""
                 unit = 1 (0x1)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "floppy0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -global floppy.drive=none0 -device
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -device floppy
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = ""
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -device floppy,drive-type=120
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = ""
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -device floppy,drive-type=144
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = ""
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -device floppy,drive-type=288
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = ""
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,drive-t
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,drive-t
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,logical
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
@@ -XXX,XX +XXX,XX @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,physica
               dev: floppy, id ""
                 unit = 0 (0x0)
                 drive = "none0"
+                backend_defaults = "auto"
                 logical_block_size = 512 (512 B)
                 physical_block_size = 512 (512 B)
                 min_io_size = 0 (0 B)
-- 
2.31.1