The following changes since commit deabea6e88f7c4c3c12a36ee30051c6209561165: Merge tag 'for_upstream' of https://git.kernel.org/pub/scm/virt/kvm/mst/qemu into staging (2023-02-02 10:10:07 +0000) are available in the Git repository at: https://gitlab.com/juan.quintela/qemu.git tags/next-pull-request for you to fetch changes up to 5ee6d3d1eeccd85aa2a835e82b8d9e1b4f7441e1: migration: check magic value for deciding the mapping of channels (2023-02-02 17:04:16 +0100) ---------------------------------------------------------------- Migration PULL request, new try Hi It includes: - David Hildenbrand fixes for virtio-men - David Gilbert canary to detect problems - Fix for rdma return values (Fiona) - Peter Xu uffd_open fixes - Peter Xu show right downtime for postcopy - manish.mishra msg fix fixes - my vfio changes. Please apply. Please, apply. ---------------------------------------------------------------- David Hildenbrand (13): migration/ram: Fix populate_read_range() migration/ram: Fix error handling in ram_write_tracking_start() migration/ram: Don't explicitly unprotect when unregistering uffd-wp migration/ram: Rely on used_length for uffd_change_protection() migration/ram: Optimize ram_write_tracking_start() for RamDiscardManager migration/savevm: Move more savevm handling into vmstate_save() migration/savevm: Prepare vmdesc json writer in qemu_savevm_state_setup() migration/savevm: Allow immutable device state to be migrated early (i.e., before RAM) migration/vmstate: Introduce VMSTATE_WITH_TMP_TEST() and VMSTATE_BITMAP_TEST() migration/ram: Factor out check for advised postcopy virtio-mem: Fail if a memory backend with "prealloc=on" is specified virtio-mem: Migrate immutable properties early virtio-mem: Proper support for preallocation with migration Dr. David Alan Gilbert (2): migration: Add canary to VMSTATE_END_OF_LIST migration: Perform vmsd structure check during tests Fiona Ebner (1): migration/rdma: fix return value for qio_channel_rdma_{readv,writev} Juan Quintela (4): migration: No save_live_pending() method uses the QEMUFile parameter migration: Split save_live_pending() into state_pending_* migration: Remove unused threshold_size parameter migration: simplify migration_iteration_run() Peter Xu (3): migration: Fix migration crash when target psize larger than host util/userfaultfd: Add uffd_open() migration: Show downtime during postcopy phase Zhenzhong Duan (1): migration/dirtyrate: Show sample pages only in page-sampling mode manish.mishra (2): io: Add support for MSG_PEEK for socket channel migration: check magic value for deciding the mapping of channels docs/devel/migration.rst | 18 +-- docs/devel/vfio-migration.rst | 4 +- include/hw/virtio/virtio-mem.h | 8 ++ include/io/channel.h | 6 + include/migration/misc.h | 4 +- include/migration/register.h | 17 +-- include/migration/vmstate.h | 35 +++++- include/qemu/userfaultfd.h | 8 ++ migration/channel.h | 5 + migration/migration.h | 4 + migration/multifd.h | 2 +- migration/postcopy-ram.h | 2 +- migration/savevm.h | 10 +- chardev/char-socket.c | 4 +- hw/core/machine.c | 4 +- hw/s390x/s390-stattrib.c | 11 +- hw/vfio/migration.c | 20 +-- hw/virtio/virtio-mem.c | 144 ++++++++++++++++++++- io/channel-buffer.c | 1 + io/channel-command.c | 1 + io/channel-file.c | 1 + io/channel-null.c | 1 + io/channel-socket.c | 19 ++- io/channel-tls.c | 1 + io/channel-websock.c | 1 + io/channel.c | 16 ++- migration/block-dirty-bitmap.c | 14 +-- migration/block.c | 13 +- migration/channel-block.c | 1 + migration/channel.c | 45 +++++++ migration/dirtyrate.c | 10 +- migration/migration.c | 119 ++++++++++++------ migration/multifd.c | 19 +-- migration/postcopy-ram.c | 16 +-- migration/ram.c | 120 +++++++++++++----- migration/rdma.c | 16 ++- migration/savevm.c | 187 ++++++++++++++++++++-------- migration/vmstate.c | 2 + scsi/qemu-pr-helper.c | 2 +- tests/qtest/migration-test.c | 3 +- tests/qtest/tpm-emu.c | 2 +- tests/unit/test-io-channel-socket.c | 1 + util/userfaultfd.c | 13 +- util/vhost-user-server.c | 2 +- hw/vfio/trace-events | 2 +- migration/trace-events | 7 +- 46 files changed, 715 insertions(+), 226 deletions(-) -- 2.39.1 From: Peter Xu <peterx@redhat.com> Commit d9e474ea56 overlooked the case where the target psize is even larger than the host psize. One example is Alpha has 8K page size and migration will start to crash the source QEMU when running Alpha migration on x86. Fix it by detecting that case and set host start/end just to cover the single page to be migrated. This will slightly optimize the common case where host psize equals to guest psize so we don't even need to do the roundups, but that's trivial. Cc: qemu-stable@nongnu.org Reported-by: Thomas Huth <thuth@redhat.com> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1456 Fixes: d9e474ea56 ("migration: Teach PSS about host page") Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/ram.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -XXX,XX +XXX,XX @@ static void pss_host_page_prepare(PageSearchStatus *pss) size_t guest_pfns = qemu_ram_pagesize(pss->block) >> TARGET_PAGE_BITS; pss->host_page_sending = true; - pss->host_page_start = ROUND_DOWN(pss->page, guest_pfns); - pss->host_page_end = ROUND_UP(pss->page + 1, guest_pfns); + if (guest_pfns <= 1) { + /* + * This covers both when guest psize == host psize, or when guest + * has larger psize than the host (guest_pfns==0). + * + * For the latter, we always send one whole guest page per + * iteration of the host page (example: an Alpha VM on x86 host + * will have guest psize 8K while host psize 4K). + */ + pss->host_page_start = pss->page; + pss->host_page_end = pss->page + 1; + } else { + /* + * The host page spans over multiple guest pages, we send them + * within the same host page iteration. + */ + pss->host_page_start = ROUND_DOWN(pss->page, guest_pfns); + pss->host_page_end = ROUND_UP(pss->page + 1, guest_pfns); + } } /* -- 2.39.1 So remove it everywhere. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> --- include/migration/register.h | 2 +- migration/savevm.h | 2 +- hw/s390x/s390-stattrib.c | 2 +- hw/vfio/migration.c | 2 +- migration/block-dirty-bitmap.c | 2 +- migration/block.c | 2 +- migration/migration.c | 2 +- migration/ram.c | 2 +- migration/savevm.c | 4 ++-- 9 files changed, 10 insertions(+), 10 deletions(-) diff --git a/include/migration/register.h b/include/migration/register.h index XXXXXXX..XXXXXXX 100644 --- a/include/migration/register.h +++ b/include/migration/register.h @@ -XXX,XX +XXX,XX @@ typedef struct SaveVMHandlers { /* This runs outside the iothread lock! */ int (*save_setup)(QEMUFile *f, void *opaque); - void (*save_live_pending)(QEMUFile *f, void *opaque, + void (*save_live_pending)(void *opaque, uint64_t threshold_size, uint64_t *res_precopy_only, uint64_t *res_compatible, diff --git a/migration/savevm.h b/migration/savevm.h index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.h +++ b/migration/savevm.h @@ -XXX,XX +XXX,XX @@ void qemu_savevm_state_cleanup(void); void qemu_savevm_state_complete_postcopy(QEMUFile *f); int qemu_savevm_state_complete_precopy(QEMUFile *f, bool iterable_only, bool inactivate_disks); -void qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size, +void qemu_savevm_state_pending(uint64_t max_size, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only); diff --git a/hw/s390x/s390-stattrib.c b/hw/s390x/s390-stattrib.c index XXXXXXX..XXXXXXX 100644 --- a/hw/s390x/s390-stattrib.c +++ b/hw/s390x/s390-stattrib.c @@ -XXX,XX +XXX,XX @@ static int cmma_save_setup(QEMUFile *f, void *opaque) return 0; } -static void cmma_save_pending(QEMUFile *f, void *opaque, uint64_t max_size, +static void cmma_save_pending(void *opaque, uint64_t max_size, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index XXXXXXX..XXXXXXX 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -XXX,XX +XXX,XX @@ static void vfio_save_cleanup(void *opaque) trace_vfio_save_cleanup(vbasedev->name); } -static void vfio_save_pending(QEMUFile *f, void *opaque, +static void vfio_save_pending(void *opaque, uint64_t threshold_size, uint64_t *res_precopy_only, uint64_t *res_compatible, diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c index XXXXXXX..XXXXXXX 100644 --- a/migration/block-dirty-bitmap.c +++ b/migration/block-dirty-bitmap.c @@ -XXX,XX +XXX,XX @@ static int dirty_bitmap_save_complete(QEMUFile *f, void *opaque) return 0; } -static void dirty_bitmap_save_pending(QEMUFile *f, void *opaque, +static void dirty_bitmap_save_pending(void *opaque, uint64_t max_size, uint64_t *res_precopy_only, uint64_t *res_compatible, diff --git a/migration/block.c b/migration/block.c index XXXXXXX..XXXXXXX 100644 --- a/migration/block.c +++ b/migration/block.c @@ -XXX,XX +XXX,XX @@ static int block_save_complete(QEMUFile *f, void *opaque) return 0; } -static void block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size, +static void block_save_pending(void *opaque, uint64_t max_size, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) diff --git a/migration/migration.c b/migration/migration.c index XXXXXXX..XXXXXXX 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -XXX,XX +XXX,XX @@ static MigIterateState migration_iteration_run(MigrationState *s) uint64_t pending_size, pend_pre, pend_compat, pend_post; bool in_postcopy = s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE; - qemu_savevm_state_pending(s->to_dst_file, s->threshold_size, &pend_pre, + qemu_savevm_state_pending(s->threshold_size, &pend_pre, &pend_compat, &pend_post); pending_size = pend_pre + pend_compat + pend_post; diff --git a/migration/ram.c b/migration/ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -XXX,XX +XXX,XX @@ static int ram_save_complete(QEMUFile *f, void *opaque) return 0; } -static void ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size, +static void ram_save_pending(void *opaque, uint64_t max_size, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) diff --git a/migration/savevm.c b/migration/savevm.c index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -XXX,XX +XXX,XX @@ flush: * the result is split into the amount for units that can and * for units that can't do postcopy. */ -void qemu_savevm_state_pending(QEMUFile *f, uint64_t threshold_size, +void qemu_savevm_state_pending(uint64_t threshold_size, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) @@ -XXX,XX +XXX,XX @@ void qemu_savevm_state_pending(QEMUFile *f, uint64_t threshold_size, continue; } } - se->ops->save_live_pending(f, se->opaque, threshold_size, + se->ops->save_live_pending(se->opaque, threshold_size, res_precopy_only, res_compatible, res_postcopy_only); } -- 2.39.1 We split the function into to: - state_pending_estimate: We estimate the remaining state size without stopping the machine. - state pending_exact: We calculate the exact amount of remaining state. The only "device" that implements different functions for _estimate() and _exact() is ram. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> --- docs/devel/migration.rst | 18 ++++++++------- docs/devel/vfio-migration.rst | 4 ++-- include/migration/register.h | 19 +++++++++------ migration/savevm.h | 12 ++++++---- hw/s390x/s390-stattrib.c | 11 +++++---- hw/vfio/migration.c | 21 +++++++++-------- migration/block-dirty-bitmap.c | 15 ++++++------ migration/block.c | 13 ++++++----- migration/migration.c | 20 +++++++++++----- migration/ram.c | 35 ++++++++++++++++++++-------- migration/savevm.c | 42 +++++++++++++++++++++++++++------- hw/vfio/trace-events | 2 +- migration/trace-events | 7 +++--- 13 files changed, 143 insertions(+), 76 deletions(-) diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst index XXXXXXX..XXXXXXX 100644 --- a/docs/devel/migration.rst +++ b/docs/devel/migration.rst @@ -XXX,XX +XXX,XX @@ An iterative device must provide: - A ``load_setup`` function that initialises the data structures on the destination. - - A ``save_live_pending`` function that is called repeatedly and must - indicate how much more data the iterative data must save. The core - migration code will use this to determine when to pause the CPUs - and complete the migration. + - A ``state_pending_exact`` function that indicates how much more + data we must save. The core migration code will use this to + determine when to pause the CPUs and complete the migration. - - A ``save_live_iterate`` function (called after ``save_live_pending`` - when there is significant data still to be sent). It should send - a chunk of data until the point that stream bandwidth limits tell it - to stop. Each call generates one section. + - A ``state_pending_estimate`` function that indicates how much more + data we must save. When the estimated amount is smaller than the + threshold, we call ``state_pending_exact``. + + - A ``save_live_iterate`` function should send a chunk of data until + the point that stream bandwidth limits tell it to stop. Each call + generates one section. - A ``save_live_complete_precopy`` function that must transmit the last section for the device containing any remaining data. diff --git a/docs/devel/vfio-migration.rst b/docs/devel/vfio-migration.rst index XXXXXXX..XXXXXXX 100644 --- a/docs/devel/vfio-migration.rst +++ b/docs/devel/vfio-migration.rst @@ -XXX,XX +XXX,XX @@ VFIO implements the device hooks for the iterative approach as follows: * A ``load_setup`` function that sets up the migration region on the destination and sets _RESUMING flag in the VFIO device state. -* A ``save_live_pending`` function that reads pending_bytes from the vendor +* A ``state_pending_exact`` function that reads pending_bytes from the vendor driver, which indicates the amount of data that the vendor driver has yet to save for the VFIO device. @@ -XXX,XX +XXX,XX @@ Live migration save path (RUNNING, _SETUP, _RUNNING|_SAVING) | (RUNNING, _ACTIVE, _RUNNING|_SAVING) - If device is active, get pending_bytes by .save_live_pending() + If device is active, get pending_bytes by .state_pending_exact() If total pending_bytes >= threshold_size, call .save_live_iterate() Data of VFIO device for pre-copy phase is copied Iterate till total pending bytes converge and are less than threshold diff --git a/include/migration/register.h b/include/migration/register.h index XXXXXXX..XXXXXXX 100644 --- a/include/migration/register.h +++ b/include/migration/register.h @@ -XXX,XX +XXX,XX @@ typedef struct SaveVMHandlers { /* This runs outside the iothread lock! */ int (*save_setup)(QEMUFile *f, void *opaque); - void (*save_live_pending)(void *opaque, - uint64_t threshold_size, - uint64_t *res_precopy_only, - uint64_t *res_compatible, - uint64_t *res_postcopy_only); /* Note for save_live_pending: * - res_precopy_only is for data which must be migrated in precopy phase * or in stopped state, in other words - before target vm start @@ -XXX,XX +XXX,XX @@ typedef struct SaveVMHandlers { * Sum of res_postcopy_only, res_compatible and res_postcopy_only is the * whole amount of pending data. */ - - + /* This estimates the remaining data to transfer */ + void (*state_pending_estimate)(void *opaque, + uint64_t threshold_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only); + /* This calculate the exact remaining data to transfer */ + void (*state_pending_exact)(void *opaque, + uint64_t threshold_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only); LoadStateHandler *load_state; int (*load_setup)(QEMUFile *f, void *opaque); int (*load_cleanup)(void *opaque); diff --git a/migration/savevm.h b/migration/savevm.h index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.h +++ b/migration/savevm.h @@ -XXX,XX +XXX,XX @@ void qemu_savevm_state_cleanup(void); void qemu_savevm_state_complete_postcopy(QEMUFile *f); int qemu_savevm_state_complete_precopy(QEMUFile *f, bool iterable_only, bool inactivate_disks); -void qemu_savevm_state_pending(uint64_t max_size, - uint64_t *res_precopy_only, - uint64_t *res_compatible, - uint64_t *res_postcopy_only); +void qemu_savevm_state_pending_exact(uint64_t threshold_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only); +void qemu_savevm_state_pending_estimate(uint64_t thershold_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only); void qemu_savevm_send_ping(QEMUFile *f, uint32_t value); void qemu_savevm_send_open_return_path(QEMUFile *f); int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len); diff --git a/hw/s390x/s390-stattrib.c b/hw/s390x/s390-stattrib.c index XXXXXXX..XXXXXXX 100644 --- a/hw/s390x/s390-stattrib.c +++ b/hw/s390x/s390-stattrib.c @@ -XXX,XX +XXX,XX @@ static int cmma_save_setup(QEMUFile *f, void *opaque) return 0; } -static void cmma_save_pending(void *opaque, uint64_t max_size, - uint64_t *res_precopy_only, - uint64_t *res_compatible, - uint64_t *res_postcopy_only) +static void cmma_state_pending(void *opaque, uint64_t max_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only) { S390StAttribState *sas = S390_STATTRIB(opaque); S390StAttribClass *sac = S390_STATTRIB_GET_CLASS(sas); @@ -XXX,XX +XXX,XX @@ static SaveVMHandlers savevm_s390_stattrib_handlers = { .save_setup = cmma_save_setup, .save_live_iterate = cmma_save_iterate, .save_live_complete_precopy = cmma_save_complete, - .save_live_pending = cmma_save_pending, + .state_pending_exact = cmma_state_pending, + .state_pending_estimate = cmma_state_pending, .save_cleanup = cmma_save_cleanup, .load_state = cmma_load, .is_active = cmma_active, diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index XXXXXXX..XXXXXXX 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -XXX,XX +XXX,XX @@ static void vfio_save_cleanup(void *opaque) trace_vfio_save_cleanup(vbasedev->name); } -static void vfio_save_pending(void *opaque, - uint64_t threshold_size, - uint64_t *res_precopy_only, - uint64_t *res_compatible, - uint64_t *res_postcopy_only) +static void vfio_state_pending(void *opaque, + uint64_t threshold_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only) { VFIODevice *vbasedev = opaque; VFIOMigration *migration = vbasedev->migration; @@ -XXX,XX +XXX,XX @@ static void vfio_save_pending(void *opaque, *res_precopy_only += migration->pending_bytes; - trace_vfio_save_pending(vbasedev->name, *res_precopy_only, + trace_vfio_state_pending(vbasedev->name, *res_precopy_only, *res_postcopy_only, *res_compatible); } @@ -XXX,XX +XXX,XX @@ static int vfio_save_iterate(QEMUFile *f, void *opaque) } /* - * Reset pending_bytes as .save_live_pending is not called during savevm or - * snapshot case, in such case vfio_update_pending() at the start of this - * function updates pending_bytes. + * Reset pending_bytes as state_pending* are not called during + * savevm or snapshot case, in such case vfio_update_pending() at + * the start of this function updates pending_bytes. */ migration->pending_bytes = 0; trace_vfio_save_iterate(vbasedev->name, data_size); @@ -XXX,XX +XXX,XX @@ static int vfio_load_state(QEMUFile *f, void *opaque, int version_id) static SaveVMHandlers savevm_vfio_handlers = { .save_setup = vfio_save_setup, .save_cleanup = vfio_save_cleanup, - .save_live_pending = vfio_save_pending, + .state_pending_exact = vfio_state_pending, + .state_pending_estimate = vfio_state_pending, .save_live_iterate = vfio_save_iterate, .save_live_complete_precopy = vfio_save_complete_precopy, .save_state = vfio_save_state, diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c index XXXXXXX..XXXXXXX 100644 --- a/migration/block-dirty-bitmap.c +++ b/migration/block-dirty-bitmap.c @@ -XXX,XX +XXX,XX @@ static int dirty_bitmap_save_complete(QEMUFile *f, void *opaque) return 0; } -static void dirty_bitmap_save_pending(void *opaque, - uint64_t max_size, - uint64_t *res_precopy_only, - uint64_t *res_compatible, - uint64_t *res_postcopy_only) +static void dirty_bitmap_state_pending(void *opaque, + uint64_t max_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only) { DBMSaveState *s = &((DBMState *)opaque)->save; SaveBitmapState *dbms; @@ -XXX,XX +XXX,XX @@ static void dirty_bitmap_save_pending(void *opaque, qemu_mutex_unlock_iothread(); - trace_dirty_bitmap_save_pending(pending, max_size); + trace_dirty_bitmap_state_pending(pending); *res_postcopy_only += pending; } @@ -XXX,XX +XXX,XX @@ static SaveVMHandlers savevm_dirty_bitmap_handlers = { .save_live_complete_postcopy = dirty_bitmap_save_complete, .save_live_complete_precopy = dirty_bitmap_save_complete, .has_postcopy = dirty_bitmap_has_postcopy, - .save_live_pending = dirty_bitmap_save_pending, + .state_pending_exact = dirty_bitmap_state_pending, + .state_pending_estimate = dirty_bitmap_state_pending, .save_live_iterate = dirty_bitmap_save_iterate, .is_active_iterate = dirty_bitmap_is_active_iterate, .load_state = dirty_bitmap_load, diff --git a/migration/block.c b/migration/block.c index XXXXXXX..XXXXXXX 100644 --- a/migration/block.c +++ b/migration/block.c @@ -XXX,XX +XXX,XX @@ static int block_save_complete(QEMUFile *f, void *opaque) return 0; } -static void block_save_pending(void *opaque, uint64_t max_size, - uint64_t *res_precopy_only, - uint64_t *res_compatible, - uint64_t *res_postcopy_only) +static void block_state_pending(void *opaque, uint64_t max_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only) { /* Estimate pending number of bytes to send */ uint64_t pending; @@ -XXX,XX +XXX,XX @@ static void block_save_pending(void *opaque, uint64_t max_size, pending = BLK_MIG_BLOCK_SIZE; } - trace_migration_block_save_pending(pending); + trace_migration_block_state_pending(pending); /* We don't do postcopy */ *res_precopy_only += pending; } @@ -XXX,XX +XXX,XX @@ static SaveVMHandlers savevm_block_handlers = { .save_setup = block_save_setup, .save_live_iterate = block_save_iterate, .save_live_complete_precopy = block_save_complete, - .save_live_pending = block_save_pending, + .state_pending_exact = block_state_pending, + .state_pending_estimate = block_state_pending, .load_state = block_load, .save_cleanup = block_migration_cleanup, .is_active = block_is_active, diff --git a/migration/migration.c b/migration/migration.c index XXXXXXX..XXXXXXX 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -XXX,XX +XXX,XX @@ typedef enum { */ static MigIterateState migration_iteration_run(MigrationState *s) { - uint64_t pending_size, pend_pre, pend_compat, pend_post; + uint64_t pend_pre, pend_compat, pend_post; bool in_postcopy = s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE; - qemu_savevm_state_pending(s->threshold_size, &pend_pre, - &pend_compat, &pend_post); - pending_size = pend_pre + pend_compat + pend_post; + qemu_savevm_state_pending_estimate(s->threshold_size, &pend_pre, + &pend_compat, &pend_post); + uint64_t pending_size = pend_pre + pend_compat + pend_post; - trace_migrate_pending(pending_size, s->threshold_size, - pend_pre, pend_compat, pend_post); + trace_migrate_pending_estimate(pending_size, s->threshold_size, + pend_pre, pend_compat, pend_post); + + if (pend_pre + pend_compat <= s->threshold_size) { + qemu_savevm_state_pending_exact(s->threshold_size, &pend_pre, + &pend_compat, &pend_post); + pending_size = pend_pre + pend_compat + pend_post; + trace_migrate_pending_exact(pending_size, s->threshold_size, + pend_pre, pend_compat, pend_post); + } if (pending_size && pending_size >= s->threshold_size) { /* Still a significant amount to transfer */ diff --git a/migration/ram.c b/migration/ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -XXX,XX +XXX,XX @@ static int ram_save_complete(QEMUFile *f, void *opaque) return 0; } -static void ram_save_pending(void *opaque, uint64_t max_size, - uint64_t *res_precopy_only, - uint64_t *res_compatible, - uint64_t *res_postcopy_only) +static void ram_state_pending_estimate(void *opaque, uint64_t max_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only) { RAMState **temp = opaque; RAMState *rs = *temp; - uint64_t remaining_size; - remaining_size = rs->migration_dirty_pages * TARGET_PAGE_SIZE; + uint64_t remaining_size = rs->migration_dirty_pages * TARGET_PAGE_SIZE; - if (!migration_in_postcopy() && - remaining_size < max_size) { + if (migrate_postcopy_ram()) { + /* We can do postcopy, and all the data is postcopiable */ + *res_postcopy_only += remaining_size; + } else { + *res_precopy_only += remaining_size; + } +} + +static void ram_state_pending_exact(void *opaque, uint64_t max_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only) +{ + RAMState **temp = opaque; + RAMState *rs = *temp; + + uint64_t remaining_size = rs->migration_dirty_pages * TARGET_PAGE_SIZE; + + if (!migration_in_postcopy()) { qemu_mutex_lock_iothread(); WITH_RCU_READ_LOCK_GUARD() { migration_bitmap_sync_precopy(rs); @@ -XXX,XX +XXX,XX @@ static SaveVMHandlers savevm_ram_handlers = { .save_live_complete_postcopy = ram_save_complete, .save_live_complete_precopy = ram_save_complete, .has_postcopy = ram_has_postcopy, - .save_live_pending = ram_save_pending, + .state_pending_exact = ram_state_pending_exact, + .state_pending_estimate = ram_state_pending_estimate, .load_state = ram_load, .save_cleanup = ram_save_cleanup, .load_setup = ram_load_setup, diff --git a/migration/savevm.c b/migration/savevm.c index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -XXX,XX +XXX,XX @@ flush: * the result is split into the amount for units that can and * for units that can't do postcopy. */ -void qemu_savevm_state_pending(uint64_t threshold_size, - uint64_t *res_precopy_only, - uint64_t *res_compatible, - uint64_t *res_postcopy_only) +void qemu_savevm_state_pending_estimate(uint64_t threshold_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only) { SaveStateEntry *se; @@ -XXX,XX +XXX,XX @@ void qemu_savevm_state_pending(uint64_t threshold_size, QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { - if (!se->ops || !se->ops->save_live_pending) { + if (!se->ops || !se->ops->state_pending_exact) { continue; } if (se->ops->is_active) { @@ -XXX,XX +XXX,XX @@ void qemu_savevm_state_pending(uint64_t threshold_size, continue; } } - se->ops->save_live_pending(se->opaque, threshold_size, - res_precopy_only, res_compatible, - res_postcopy_only); + se->ops->state_pending_exact(se->opaque, threshold_size, + res_precopy_only, res_compatible, + res_postcopy_only); + } +} + +void qemu_savevm_state_pending_exact(uint64_t threshold_size, + uint64_t *res_precopy_only, + uint64_t *res_compatible, + uint64_t *res_postcopy_only) +{ + SaveStateEntry *se; + + *res_precopy_only = 0; + *res_compatible = 0; + *res_postcopy_only = 0; + + QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { + if (!se->ops || !se->ops->state_pending_estimate) { + continue; + } + if (se->ops->is_active) { + if (!se->ops->is_active(se->opaque)) { + continue; + } + } + se->ops->state_pending_estimate(se->opaque, threshold_size, + res_precopy_only, res_compatible, + res_postcopy_only); } } diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index XXXXXXX..XXXXXXX 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -XXX,XX +XXX,XX @@ vfio_save_cleanup(const char *name) " (%s)" vfio_save_buffer(const char *name, uint64_t data_offset, uint64_t data_size, uint64_t pending) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64" pending 0x%"PRIx64 vfio_update_pending(const char *name, uint64_t pending) " (%s) pending 0x%"PRIx64 vfio_save_device_config_state(const char *name) " (%s)" -vfio_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64 +vfio_state_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64 vfio_save_iterate(const char *name, int data_size) " (%s) data_size %d" vfio_save_complete_precopy(const char *name) " (%s)" vfio_load_device_config_state(const char *name) " (%s)" diff --git a/migration/trace-events b/migration/trace-events index XXXXXXX..XXXXXXX 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -XXX,XX +XXX,XX @@ migrate_fd_cleanup(void) "" migrate_fd_error(const char *error_desc) "error=%s" migrate_fd_cancel(void) "" migrate_handle_rp_req_pages(const char *rbname, size_t start, size_t len) "in %s at 0x%zx len 0x%zx" -migrate_pending(uint64_t size, uint64_t max, uint64_t pre, uint64_t compat, uint64_t post) "pending size %" PRIu64 " max %" PRIu64 " (pre = %" PRIu64 " compat=%" PRIu64 " post=%" PRIu64 ")" +migrate_pending_exact(uint64_t size, uint64_t max, uint64_t pre, uint64_t compat, uint64_t post) "exact pending size %" PRIu64 " max %" PRIu64 " (pre = %" PRIu64 " compat=%" PRIu64 " post=%" PRIu64 ")" +migrate_pending_estimate(uint64_t size, uint64_t max, uint64_t pre, uint64_t compat, uint64_t post) "estimate pending size %" PRIu64 " max %" PRIu64 " (pre = %" PRIu64 " compat=%" PRIu64 " post=%" PRIu64 ")" migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d" migrate_send_rp_recv_bitmap(char *name, int64_t size) "block '%s' size 0x%"PRIi64 migration_completion_file_err(void) "" @@ -XXX,XX +XXX,XX @@ send_bitmap_bits(uint32_t flags, uint64_t start_sector, uint32_t nr_sectors, uin dirty_bitmap_save_iterate(int in_postcopy) "in postcopy: %d" dirty_bitmap_save_complete_enter(void) "" dirty_bitmap_save_complete_finish(void) "" -dirty_bitmap_save_pending(uint64_t pending, uint64_t max_size) "pending %" PRIu64 " max: %" PRIu64 +dirty_bitmap_state_pending(uint64_t pending) "pending %" PRIu64 dirty_bitmap_load_complete(void) "" dirty_bitmap_load_bits_enter(uint64_t first_sector, uint32_t nr_sectors) "chunk: %" PRIu64 " %" PRIu32 dirty_bitmap_load_bits_zeroes(void) "" @@ -XXX,XX +XXX,XX @@ migration_block_save_device_dirty(int64_t sector) "Error reading sector %" PRId6 migration_block_flush_blks(const char *action, int submitted, int read_done, int transferred) "%s submitted %d read_done %d transferred %d" migration_block_save(const char *mig_stage, int submitted, int transferred) "Enter save live %s submitted %d transferred %d" migration_block_save_complete(void) "Block migration completed" -migration_block_save_pending(uint64_t pending) "Enter save live pending %" PRIu64 +migration_block_state_pending(uint64_t pending) "Enter save live pending %" PRIu64 # page_cache.c migration_pagecache_init(int64_t max_num_items) "Setting cache buckets to %" PRId64 -- 2.39.1 Until previous commit, save_live_pending() was used for ram. Now with the split into state_pending_estimate() and state_pending_exact() it is not needed anymore, so remove them. Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> --- include/migration/register.h | 2 -- migration/savevm.h | 6 ++---- hw/s390x/s390-stattrib.c | 2 +- hw/vfio/migration.c | 1 - migration/block-dirty-bitmap.c | 1 - migration/block.c | 2 +- migration/migration.c | 10 ++++------ migration/ram.c | 4 ++-- migration/savevm.c | 11 ++++------- migration/trace-events | 4 ++-- 10 files changed, 16 insertions(+), 27 deletions(-) diff --git a/include/migration/register.h b/include/migration/register.h index XXXXXXX..XXXXXXX 100644 --- a/include/migration/register.h +++ b/include/migration/register.h @@ -XXX,XX +XXX,XX @@ typedef struct SaveVMHandlers { */ /* This estimates the remaining data to transfer */ void (*state_pending_estimate)(void *opaque, - uint64_t threshold_size, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only); /* This calculate the exact remaining data to transfer */ void (*state_pending_exact)(void *opaque, - uint64_t threshold_size, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only); diff --git a/migration/savevm.h b/migration/savevm.h index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.h +++ b/migration/savevm.h @@ -XXX,XX +XXX,XX @@ void qemu_savevm_state_cleanup(void); void qemu_savevm_state_complete_postcopy(QEMUFile *f); int qemu_savevm_state_complete_precopy(QEMUFile *f, bool iterable_only, bool inactivate_disks); -void qemu_savevm_state_pending_exact(uint64_t threshold_size, - uint64_t *res_precopy_only, +void qemu_savevm_state_pending_exact(uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only); -void qemu_savevm_state_pending_estimate(uint64_t thershold_size, - uint64_t *res_precopy_only, +void qemu_savevm_state_pending_estimate(uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only); void qemu_savevm_send_ping(QEMUFile *f, uint32_t value); diff --git a/hw/s390x/s390-stattrib.c b/hw/s390x/s390-stattrib.c index XXXXXXX..XXXXXXX 100644 --- a/hw/s390x/s390-stattrib.c +++ b/hw/s390x/s390-stattrib.c @@ -XXX,XX +XXX,XX @@ static int cmma_save_setup(QEMUFile *f, void *opaque) return 0; } -static void cmma_state_pending(void *opaque, uint64_t max_size, +static void cmma_state_pending(void *opaque, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index XXXXXXX..XXXXXXX 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -XXX,XX +XXX,XX @@ static void vfio_save_cleanup(void *opaque) } static void vfio_state_pending(void *opaque, - uint64_t threshold_size, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c index XXXXXXX..XXXXXXX 100644 --- a/migration/block-dirty-bitmap.c +++ b/migration/block-dirty-bitmap.c @@ -XXX,XX +XXX,XX @@ static int dirty_bitmap_save_complete(QEMUFile *f, void *opaque) } static void dirty_bitmap_state_pending(void *opaque, - uint64_t max_size, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) diff --git a/migration/block.c b/migration/block.c index XXXXXXX..XXXXXXX 100644 --- a/migration/block.c +++ b/migration/block.c @@ -XXX,XX +XXX,XX @@ static int block_save_complete(QEMUFile *f, void *opaque) return 0; } -static void block_state_pending(void *opaque, uint64_t max_size, +static void block_state_pending(void *opaque, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) diff --git a/migration/migration.c b/migration/migration.c index XXXXXXX..XXXXXXX 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -XXX,XX +XXX,XX @@ static MigIterateState migration_iteration_run(MigrationState *s) uint64_t pend_pre, pend_compat, pend_post; bool in_postcopy = s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE; - qemu_savevm_state_pending_estimate(s->threshold_size, &pend_pre, - &pend_compat, &pend_post); + qemu_savevm_state_pending_estimate(&pend_pre, &pend_compat, &pend_post); uint64_t pending_size = pend_pre + pend_compat + pend_post; - trace_migrate_pending_estimate(pending_size, s->threshold_size, + trace_migrate_pending_estimate(pending_size, pend_pre, pend_compat, pend_post); if (pend_pre + pend_compat <= s->threshold_size) { - qemu_savevm_state_pending_exact(s->threshold_size, &pend_pre, - &pend_compat, &pend_post); + qemu_savevm_state_pending_exact(&pend_pre, &pend_compat, &pend_post); pending_size = pend_pre + pend_compat + pend_post; - trace_migrate_pending_exact(pending_size, s->threshold_size, + trace_migrate_pending_exact(pending_size, pend_pre, pend_compat, pend_post); } diff --git a/migration/ram.c b/migration/ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -XXX,XX +XXX,XX @@ static int ram_save_complete(QEMUFile *f, void *opaque) return 0; } -static void ram_state_pending_estimate(void *opaque, uint64_t max_size, +static void ram_state_pending_estimate(void *opaque, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) @@ -XXX,XX +XXX,XX @@ static void ram_state_pending_estimate(void *opaque, uint64_t max_size, } } -static void ram_state_pending_exact(void *opaque, uint64_t max_size, +static void ram_state_pending_exact(void *opaque, uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) diff --git a/migration/savevm.c b/migration/savevm.c index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -XXX,XX +XXX,XX @@ flush: * the result is split into the amount for units that can and * for units that can't do postcopy. */ -void qemu_savevm_state_pending_estimate(uint64_t threshold_size, - uint64_t *res_precopy_only, +void qemu_savevm_state_pending_estimate(uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) { @@ -XXX,XX +XXX,XX @@ void qemu_savevm_state_pending_estimate(uint64_t threshold_size, *res_compatible = 0; *res_postcopy_only = 0; - QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { if (!se->ops || !se->ops->state_pending_exact) { continue; @@ -XXX,XX +XXX,XX @@ void qemu_savevm_state_pending_estimate(uint64_t threshold_size, continue; } } - se->ops->state_pending_exact(se->opaque, threshold_size, + se->ops->state_pending_exact(se->opaque, res_precopy_only, res_compatible, res_postcopy_only); } } -void qemu_savevm_state_pending_exact(uint64_t threshold_size, - uint64_t *res_precopy_only, +void qemu_savevm_state_pending_exact(uint64_t *res_precopy_only, uint64_t *res_compatible, uint64_t *res_postcopy_only) { @@ -XXX,XX +XXX,XX @@ void qemu_savevm_state_pending_exact(uint64_t threshold_size, continue; } } - se->ops->state_pending_estimate(se->opaque, threshold_size, + se->ops->state_pending_estimate(se->opaque, res_precopy_only, res_compatible, res_postcopy_only); } diff --git a/migration/trace-events b/migration/trace-events index XXXXXXX..XXXXXXX 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -XXX,XX +XXX,XX @@ migrate_fd_cleanup(void) "" migrate_fd_error(const char *error_desc) "error=%s" migrate_fd_cancel(void) "" migrate_handle_rp_req_pages(const char *rbname, size_t start, size_t len) "in %s at 0x%zx len 0x%zx" -migrate_pending_exact(uint64_t size, uint64_t max, uint64_t pre, uint64_t compat, uint64_t post) "exact pending size %" PRIu64 " max %" PRIu64 " (pre = %" PRIu64 " compat=%" PRIu64 " post=%" PRIu64 ")" -migrate_pending_estimate(uint64_t size, uint64_t max, uint64_t pre, uint64_t compat, uint64_t post) "estimate pending size %" PRIu64 " max %" PRIu64 " (pre = %" PRIu64 " compat=%" PRIu64 " post=%" PRIu64 ")" +migrate_pending_exact(uint64_t size, uint64_t pre, uint64_t compat, uint64_t post) "exact pending size %" PRIu64 " (pre = %" PRIu64 " compat=%" PRIu64 " post=%" PRIu64 ")" +migrate_pending_estimate(uint64_t size, uint64_t pre, uint64_t compat, uint64_t post) "estimate pending size %" PRIu64 " (pre = %" PRIu64 " compat=%" PRIu64 " post=%" PRIu64 ")" migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d" migrate_send_rp_recv_bitmap(char *name, int64_t size) "block '%s' size 0x%"PRIi64 migration_completion_file_err(void) "" -- 2.39.1 Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> --- migration/migration.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index XXXXXXX..XXXXXXX 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -XXX,XX +XXX,XX @@ static MigIterateState migration_iteration_run(MigrationState *s) pend_pre, pend_compat, pend_post); } - if (pending_size && pending_size >= s->threshold_size) { - /* Still a significant amount to transfer */ - if (!in_postcopy && pend_pre <= s->threshold_size && - qatomic_read(&s->start_postcopy)) { - if (postcopy_start(s)) { - error_report("%s: postcopy failed to start", __func__); - } - return MIG_ITERATE_SKIP; - } - /* Just another iteration step */ - qemu_savevm_state_iterate(s->to_dst_file, in_postcopy); - } else { + if (!pending_size || pending_size < s->threshold_size) { trace_migration_thread_low_pending(pending_size); migration_completion(s); return MIG_ITERATE_BREAK; } + /* Still a significant amount to transfer */ + if (!in_postcopy && pend_pre <= s->threshold_size && + qatomic_read(&s->start_postcopy)) { + if (postcopy_start(s)) { + error_report("%s: postcopy failed to start", __func__); + } + return MIG_ITERATE_SKIP; + } + + /* Just another iteration step */ + qemu_savevm_state_iterate(s->to_dst_file, in_postcopy); return MIG_ITERATE_RESUME; } -- 2.39.1 From: Peter Xu <peterx@redhat.com> Add a helper to create the uffd handle. Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- include/qemu/userfaultfd.h | 8 ++++++++ migration/postcopy-ram.c | 11 +++++------ tests/qtest/migration-test.c | 3 ++- util/userfaultfd.c | 13 +++++++++++-- 4 files changed, 26 insertions(+), 9 deletions(-) diff --git a/include/qemu/userfaultfd.h b/include/qemu/userfaultfd.h index XXXXXXX..XXXXXXX 100644 --- a/include/qemu/userfaultfd.h +++ b/include/qemu/userfaultfd.h @@ -XXX,XX +XXX,XX @@ #include "exec/hwaddr.h" #include <linux/userfaultfd.h> +/** + * uffd_open(): Open an userfaultfd handle for current context. + * + * @flags: The flags we want to pass in when creating the handle. + * + * Returns: the uffd handle if >=0, or <0 if error happens. + */ +int uffd_open(int flags); int uffd_query_features(uint64_t *features); int uffd_create_fd(uint64_t features, bool non_blocking); void uffd_close_fd(int uffd_fd); diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -XXX,XX +XXX,XX @@ #include "qemu-file.h" #include "yank_functions.h" #include "tls.h" +#include "qemu/userfaultfd.h" /* Arbitrary limit on size of each discard command, * keeps them around ~200 bytes @@ -XXX,XX +XXX,XX @@ static bool receive_ufd_features(uint64_t *features) int ufd; bool ret = true; - /* if we are here __NR_userfaultfd should exists */ - ufd = syscall(__NR_userfaultfd, O_CLOEXEC); + ufd = uffd_open(O_CLOEXEC); if (ufd == -1) { - error_report("%s: syscall __NR_userfaultfd failed: %s", __func__, - strerror(errno)); + error_report("%s: uffd_open() failed: %s", __func__, strerror(errno)); return false; } @@ -XXX,XX +XXX,XX @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis) goto out; } - ufd = syscall(__NR_userfaultfd, O_CLOEXEC); + ufd = uffd_open(O_CLOEXEC); if (ufd == -1) { error_report("%s: userfaultfd not available: %s", __func__, strerror(errno)); @@ -XXX,XX +XXX,XX @@ static int postcopy_temp_pages_setup(MigrationIncomingState *mis) int postcopy_ram_incoming_setup(MigrationIncomingState *mis) { /* Open the fd for the kernel to give us userfaults */ - mis->userfault_fd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK); + mis->userfault_fd = uffd_open(O_CLOEXEC | O_NONBLOCK); if (mis->userfault_fd == -1) { error_report("%s: Failed to open userfault fd: %s", __func__, strerror(errno)); diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c index XXXXXXX..XXXXXXX 100644 --- a/tests/qtest/migration-test.c +++ b/tests/qtest/migration-test.c @@ -XXX,XX +XXX,XX @@ static bool uffd_feature_thread_id; #include <sys/eventfd.h> #include <sys/ioctl.h> #include <linux/userfaultfd.h> +#include "qemu/userfaultfd.h" static bool ufd_version_check(void) { struct uffdio_api api_struct; uint64_t ioctl_mask; - int ufd = syscall(__NR_userfaultfd, O_CLOEXEC); + int ufd = uffd_open(O_CLOEXEC); if (ufd == -1) { g_test_message("Skipping test: userfaultfd not available"); diff --git a/util/userfaultfd.c b/util/userfaultfd.c index XXXXXXX..XXXXXXX 100644 --- a/util/userfaultfd.c +++ b/util/userfaultfd.c @@ -XXX,XX +XXX,XX @@ #include <sys/syscall.h> #include <sys/ioctl.h> +int uffd_open(int flags) +{ +#if defined(__NR_userfaultfd) + return syscall(__NR_userfaultfd, flags); +#else + return -EINVAL; +#endif +} + /** * uffd_query_features: query UFFD features * @@ -XXX,XX +XXX,XX @@ int uffd_query_features(uint64_t *features) struct uffdio_api api_struct = { 0 }; int ret = -1; - uffd_fd = syscall(__NR_userfaultfd, O_CLOEXEC); + uffd_fd = uffd_open(O_CLOEXEC); if (uffd_fd < 0) { trace_uffd_query_features_nosys(errno); return -1; @@ -XXX,XX +XXX,XX @@ int uffd_create_fd(uint64_t features, bool non_blocking) uint64_t ioctl_mask = BIT(_UFFDIO_REGISTER) | BIT(_UFFDIO_UNREGISTER); flags = O_CLOEXEC | (non_blocking ? O_NONBLOCK : 0); - uffd_fd = syscall(__NR_userfaultfd, flags); + uffd_fd = uffd_open(flags); if (uffd_fd < 0) { trace_uffd_create_fd_nosys(errno); return -1; -- 2.39.1 From: David Hildenbrand <david@redhat.com> Unfortunately, commit f7b9dcfbcf44 broke populate_read_range(): the loop end condition is very wrong, resulting in that function not populating the full range. Lets' fix that. Fixes: f7b9dcfbcf44 ("migration/ram: Factor out populating pages readable in ram_block_populate_pages()") Cc: qemu-stable@nongnu.org Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/ram.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -XXX,XX +XXX,XX @@ out: static inline void populate_read_range(RAMBlock *block, ram_addr_t offset, ram_addr_t size) { + const ram_addr_t end = offset + size; + /* * We read one byte of each page; this will preallocate page tables if * required and populate the shared zeropage on MAP_PRIVATE anonymous memory * where no page was populated yet. This might require adaption when * supporting other mappings, like shmem. */ - for (; offset < size; offset += block->page_size) { + for (; offset < end; offset += block->page_size) { char tmp = *((char *)block->host + offset); /* Don't optimize the read out */ -- 2.39.1 From: David Hildenbrand <david@redhat.com> If something goes wrong during uffd_change_protection(), we would miss to unregister uffd-wp and not release our reference. Fix it by performing the uffd_change_protection(true) last. Note that a uffd_change_protection(false) on the recovery path without a prior uffd_change_protection(false) is fine. Fixes: 278e2f551a09 ("migration: support UFFD write fault processing in ram_save_iterate()") Cc: qemu-stable@nongnu.org Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/ram.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -XXX,XX +XXX,XX @@ int ram_write_tracking_start(void) block->max_length, UFFDIO_REGISTER_MODE_WP, NULL)) { goto fail; } + block->flags |= RAM_UF_WRITEPROTECT; + memory_region_ref(block->mr); + /* Apply UFFD write protection to the block memory range */ if (uffd_change_protection(rs->uffdio_fd, block->host, block->max_length, true, false)) { goto fail; } - block->flags |= RAM_UF_WRITEPROTECT; - memory_region_ref(block->mr); trace_ram_write_tracking_ramblock_start(block->idstr, block->page_size, block->host, block->max_length); -- 2.39.1 From: David Hildenbrand <david@redhat.com> When unregistering uffd-wp, older kernels before commit f369b07c86143 ("mm/uffd:reset write protection when unregister with wp-mode") won't clear the uffd-wp PTE bit. When re-registering uffd-wp, the previous uffd-wp PTE bits would trigger again. With above commit, the kernel will clear the uffd-wp PTE bits when unregistering itself. Consequently, we'll clear the uffd-wp PTE bits now twice -- whereby we don't care about clearing them at all: a new background snapshot will re-register uffd-wp and re-protect all memory either way. So let's skip the manual clearing of uffd-wp. If ever relevant, we could clear conditionally in uffd_unregister_memory() -- we just need a way to figure out more recent kernels. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/ram.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -XXX,XX +XXX,XX @@ fail: if ((block->flags & RAM_UF_WRITEPROTECT) == 0) { continue; } - /* - * In case some memory block failed to be write-protected - * remove protection and unregister all succeeded RAM blocks - */ - uffd_change_protection(rs->uffdio_fd, block->host, block->max_length, - false, false); uffd_unregister_memory(rs->uffdio_fd, block->host, block->max_length); /* Cleanup flags and remove reference */ block->flags &= ~RAM_UF_WRITEPROTECT; @@ -XXX,XX +XXX,XX @@ void ram_write_tracking_stop(void) if ((block->flags & RAM_UF_WRITEPROTECT) == 0) { continue; } - /* Remove protection and unregister all affected RAM blocks */ - uffd_change_protection(rs->uffdio_fd, block->host, block->max_length, - false, false); uffd_unregister_memory(rs->uffdio_fd, block->host, block->max_length); trace_ram_write_tracking_ramblock_stop(block->idstr, block->page_size, -- 2.39.1 From: David Hildenbrand <david@redhat.com> ram_mig_ram_block_resized() will abort migration (including background snapshots) when resizing a RAMBlock. ram_block_populate_read() will only populate RAM up to used_length, so at least for anonymous memory protecting everything between used_length and max_length won't actually be protected and is just a NOP. So let's only protect everything up to used_length. Note: it still makes sense to register uffd-wp for max_length, such that RAM_UF_WRITEPROTECT is independent of a changing used_length. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/ram.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -XXX,XX +XXX,XX @@ int ram_write_tracking_start(void) /* Apply UFFD write protection to the block memory range */ if (uffd_change_protection(rs->uffdio_fd, block->host, - block->max_length, true, false)) { + block->used_length, true, false)) { goto fail; } -- 2.39.1 From: David Hildenbrand <david@redhat.com> ram_block_populate_read() already optimizes for RamDiscardManager. However, ram_write_tracking_start() will still try protecting discarded memory ranges. Let's optimize, because discarded ranges don't map any pages and (1) For anonymous memory, trying to protect using uffd-wp without a mapped page is ignored by the kernel and consequently a NOP. (2) For shared/file-backed memory, we will fill present page tables in the range with PTE markers. However, we will even allocate page tables just to fill them with unnecessary PTE markers and effectively waste memory. So let's exclude these ranges, just like ram_block_populate_read() already does. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/ram.c | 36 ++++++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -XXX,XX +XXX,XX @@ void ram_write_tracking_prepare(void) } } +static inline int uffd_protect_section(MemoryRegionSection *section, + void *opaque) +{ + const hwaddr size = int128_get64(section->size); + const hwaddr offset = section->offset_within_region; + RAMBlock *rb = section->mr->ram_block; + int uffd_fd = (uintptr_t)opaque; + + return uffd_change_protection(uffd_fd, rb->host + offset, size, true, + false); +} + +static int ram_block_uffd_protect(RAMBlock *rb, int uffd_fd) +{ + assert(rb->flags & RAM_UF_WRITEPROTECT); + + /* See ram_block_populate_read() */ + if (rb->mr && memory_region_has_ram_discard_manager(rb->mr)) { + RamDiscardManager *rdm = memory_region_get_ram_discard_manager(rb->mr); + MemoryRegionSection section = { + .mr = rb->mr, + .offset_within_region = 0, + .size = rb->mr->size, + }; + + return ram_discard_manager_replay_populated(rdm, &section, + uffd_protect_section, + (void *)(uintptr_t)uffd_fd); + } + return uffd_change_protection(uffd_fd, rb->host, + rb->used_length, true, false); +} + /* * ram_write_tracking_start: start UFFD-WP memory tracking * @@ -XXX,XX +XXX,XX @@ int ram_write_tracking_start(void) memory_region_ref(block->mr); /* Apply UFFD write protection to the block memory range */ - if (uffd_change_protection(rs->uffdio_fd, block->host, - block->used_length, true, false)) { + if (ram_block_uffd_protect(block, uffd_fd)) { goto fail; } -- 2.39.1 From: David Hildenbrand <david@redhat.com> Let's move more code into vmstate_save(), reducing code duplication and preparing for reuse of vmstate_save() in qemu_savevm_state_setup(). We have to move vmstate_save() to make the compiler happy. We'll now also trace from qemu_save_device_state(), triggering the same tracepoints as previously called from qemu_savevm_state_complete_precopy_non_iterable() only. Note that qemu_save_device_state() ignores iterable device state, such as RAM, and consequently doesn't trigger some other trace points (e.g., trace_savevm_state_setup()). Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/savevm.c | 79 ++++++++++++++++++++++------------------------ 1 file changed, 37 insertions(+), 42 deletions(-) diff --git a/migration/savevm.c b/migration/savevm.c index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -XXX,XX +XXX,XX @@ static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se, } } -static int vmstate_save(QEMUFile *f, SaveStateEntry *se, - JSONWriter *vmdesc) -{ - trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)"); - if (!se->vmsd) { - vmstate_save_old_style(f, se, vmdesc); - return 0; - } - return vmstate_save_state(f, se->vmsd, se->opaque, vmdesc); -} - /* * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL) */ @@ -XXX,XX +XXX,XX @@ static void save_section_footer(QEMUFile *f, SaveStateEntry *se) } } +static int vmstate_save(QEMUFile *f, SaveStateEntry *se, JSONWriter *vmdesc) +{ + int ret; + + if ((!se->ops || !se->ops->save_state) && !se->vmsd) { + return 0; + } + if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { + trace_savevm_section_skip(se->idstr, se->section_id); + return 0; + } + + trace_savevm_section_start(se->idstr, se->section_id); + save_section_header(f, se, QEMU_VM_SECTION_FULL); + if (vmdesc) { + json_writer_start_object(vmdesc, NULL); + json_writer_str(vmdesc, "name", se->idstr); + json_writer_int64(vmdesc, "instance_id", se->instance_id); + } + + trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)"); + if (!se->vmsd) { + vmstate_save_old_style(f, se, vmdesc); + } else { + ret = vmstate_save_state(f, se->vmsd, se->opaque, vmdesc); + if (ret) { + return ret; + } + } + + trace_savevm_section_end(se->idstr, se->section_id, 0); + save_section_footer(f, se); + if (vmdesc) { + json_writer_end_object(vmdesc); + } + return 0; +} /** * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the * command and associated data. @@ -XXX,XX +XXX,XX @@ int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f, json_writer_int64(vmdesc, "page_size", qemu_target_page_size()); json_writer_start_array(vmdesc, "devices"); QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { - - if ((!se->ops || !se->ops->save_state) && !se->vmsd) { - continue; - } - if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { - trace_savevm_section_skip(se->idstr, se->section_id); - continue; - } - - trace_savevm_section_start(se->idstr, se->section_id); - - json_writer_start_object(vmdesc, NULL); - json_writer_str(vmdesc, "name", se->idstr); - json_writer_int64(vmdesc, "instance_id", se->instance_id); - - save_section_header(f, se, QEMU_VM_SECTION_FULL); ret = vmstate_save(f, se, vmdesc); if (ret) { qemu_file_set_error(f, ret); return ret; } - trace_savevm_section_end(se->idstr, se->section_id, 0); - save_section_footer(f, se); - - json_writer_end_object(vmdesc); } if (inactivate_disks) { @@ -XXX,XX +XXX,XX @@ int qemu_save_device_state(QEMUFile *f) if (se->is_ram) { continue; } - if ((!se->ops || !se->ops->save_state) && !se->vmsd) { - continue; - } - if (se->vmsd && !vmstate_save_needed(se->vmsd, se->opaque)) { - continue; - } - - save_section_header(f, se, QEMU_VM_SECTION_FULL); - ret = vmstate_save(f, se, NULL); if (ret) { return ret; } - - save_section_footer(f, se); } qemu_put_byte(f, QEMU_VM_EOF); -- 2.39.1 From: David Hildenbrand <david@redhat.com> ... and store it in the migration state. This is a preparation for storing selected vmds's already in qemu_savevm_state_setup(). Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/migration.h | 4 ++++ migration/migration.c | 2 ++ migration/savevm.c | 18 ++++++++++++------ 3 files changed, 18 insertions(+), 6 deletions(-) diff --git a/migration/migration.h b/migration/migration.h index XXXXXXX..XXXXXXX 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -XXX,XX +XXX,XX @@ #include "exec/cpu-common.h" #include "hw/qdev-core.h" #include "qapi/qapi-types-migration.h" +#include "qapi/qmp/json-writer.h" #include "qemu/thread.h" #include "qemu/coroutine_int.h" #include "io/channel.h" @@ -XXX,XX +XXX,XX @@ struct MigrationState { * This save hostname when out-going migration starts */ char *hostname; + + /* QEMU_VM_VMDESCRIPTION content filled for all non-iterable devices. */ + JSONWriter *vmdesc; }; void migrate_set_state(int *state, int old_state, int new_state); diff --git a/migration/migration.c b/migration/migration.c index XXXXXXX..XXXXXXX 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -XXX,XX +XXX,XX @@ static void migrate_fd_cleanup(MigrationState *s) g_free(s->hostname); s->hostname = NULL; + json_writer_free(s->vmdesc); + s->vmdesc = NULL; qemu_savevm_state_cleanup(); diff --git a/migration/savevm.c b/migration/savevm.c index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -XXX,XX +XXX,XX @@ #include "postcopy-ram.h" #include "qapi/error.h" #include "qapi/qapi-commands-migration.h" -#include "qapi/qmp/json-writer.h" #include "qapi/clone-visitor.h" #include "qapi/qapi-builtin-visit.h" #include "qapi/qmp/qerror.h" @@ -XXX,XX +XXX,XX @@ bool qemu_savevm_state_guest_unplug_pending(void) void qemu_savevm_state_setup(QEMUFile *f) { + MigrationState *ms = migrate_get_current(); SaveStateEntry *se; Error *local_err = NULL; int ret; + ms->vmdesc = json_writer_new(false); + json_writer_start_object(ms->vmdesc, NULL); + json_writer_int64(ms->vmdesc, "page_size", qemu_target_page_size()); + json_writer_start_array(ms->vmdesc, "devices"); + trace_savevm_state_setup(); QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { if (!se->ops || !se->ops->save_setup) { @@ -XXX,XX +XXX,XX @@ int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f, bool in_postcopy, bool inactivate_disks) { - g_autoptr(JSONWriter) vmdesc = NULL; + MigrationState *ms = migrate_get_current(); + JSONWriter *vmdesc = ms->vmdesc; int vmdesc_len; SaveStateEntry *se; int ret; - vmdesc = json_writer_new(false); - json_writer_start_object(vmdesc, NULL); - json_writer_int64(vmdesc, "page_size", qemu_target_page_size()); - json_writer_start_array(vmdesc, "devices"); QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { ret = vmstate_save(f, se, vmdesc); if (ret) { @@ -XXX,XX +XXX,XX @@ int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f, qemu_put_buffer(f, (uint8_t *)json_writer_get(vmdesc), vmdesc_len); } + /* Free it now to detect any inconsistencies. */ + json_writer_free(vmdesc); + ms->vmdesc = NULL; + return 0; } -- 2.39.1 From: David Hildenbrand <david@redhat.com> For virtio-mem, we want to have the plugged/unplugged state of memory blocks available before migrating any actual RAM content, and perform sanity checks before touching anything on the destination. This information is immutable on the migration source while migration is active, We want to use this information for proper preallocation support with migration: currently, we don't preallocate memory on the migration target, and especially with hugetlb, we can easily run out of hugetlb pages during RAM migration and will crash (SIGBUS) instead of catching this gracefully via preallocation. Migrating device state via a VMSD before we start iterating is currently impossible: the only approach that would be possible is avoiding a VMSD and migrating state manually during save_setup(), to be restored during load_state(). Let's allow for migrating device state via a VMSD early, during the setup phase in qemu_savevm_state_setup(). To keep it simple, we indicate applicable VMSD's using an "early_setup" flag. Note that only very selected devices (i.e., ones seriously messing with RAM setup) are supposed to make use of such early state migration. While at it, also use a bool for the "unmigratable" member. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com>S Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- include/migration/vmstate.h | 16 +++++++++++++++- migration/savevm.c | 14 ++++++++++++++ 2 files changed, 29 insertions(+), 1 deletion(-) diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index XXXXXXX..XXXXXXX 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -XXX,XX +XXX,XX @@ struct VMStateField { struct VMStateDescription { const char *name; - int unmigratable; + bool unmigratable; + /* + * This VMSD describes something that should be sent during setup phase + * of migration. It plays similar role as save_setup() for explicitly + * registered vmstate entries, so it can be seen as a way to describe + * save_setup() in VMSD structures. + * + * Note that for now, a SaveStateEntry cannot have a VMSD and + * operations (e.g., save_setup()) set at the same time. Consequently, + * save_setup() and a VMSD with early_setup set to true are mutually + * exclusive. For this reason, also early_setup VMSDs are migrated in a + * QEMU_VM_SECTION_FULL section, while save_setup() data is migrated in + * a QEMU_VM_SECTION_START section. + */ + bool early_setup; int version_id; int minimum_version_id; MigrationPriority priority; diff --git a/migration/savevm.c b/migration/savevm.c index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -XXX,XX +XXX,XX @@ void qemu_savevm_state_setup(QEMUFile *f) trace_savevm_state_setup(); QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { + if (se->vmsd && se->vmsd->early_setup) { + ret = vmstate_save(f, se, ms->vmdesc); + if (ret) { + qemu_file_set_error(f, ret); + break; + } + continue; + } + if (!se->ops || !se->ops->save_setup) { continue; } @@ -XXX,XX +XXX,XX @@ int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f, int ret; QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { + if (se->vmsd && se->vmsd->early_setup) { + /* Already saved during qemu_savevm_state_setup(). */ + continue; + } + ret = vmstate_save(f, se, vmdesc); if (ret) { qemu_file_set_error(f, ret); -- 2.39.1 From: David Hildenbrand <david@redhat.com> We'll make use of both next in the context of virtio-mem. Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com>S Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- include/migration/vmstate.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index XXXXXXX..XXXXXXX 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -XXX,XX +XXX,XX @@ extern const VMStateInfo vmstate_info_qlist; * '_state' type * That the pointer is right at the start of _tmp_type. */ -#define VMSTATE_WITH_TMP(_state, _tmp_type, _vmsd) { \ +#define VMSTATE_WITH_TMP_TEST(_state, _test, _tmp_type, _vmsd) { \ .name = "tmp", \ + .field_exists = (_test), \ .size = sizeof(_tmp_type) + \ QEMU_BUILD_BUG_ON_ZERO(offsetof(_tmp_type, parent) != 0) + \ type_check_pointer(_state, \ @@ -XXX,XX +XXX,XX @@ extern const VMStateInfo vmstate_info_qlist; .info = &vmstate_info_tmp, \ } +#define VMSTATE_WITH_TMP(_state, _tmp_type, _vmsd) \ + VMSTATE_WITH_TMP_TEST(_state, NULL, _tmp_type, _vmsd) + #define VMSTATE_UNUSED_BUFFER(_test, _version, _size) { \ .name = "unused", \ .field_exists = (_test), \ @@ -XXX,XX +XXX,XX @@ extern const VMStateInfo vmstate_info_qlist; /* _field_size should be a int32_t field in the _state struct giving the * size of the bitmap _field in bits. */ -#define VMSTATE_BITMAP(_field, _state, _version, _field_size) { \ +#define VMSTATE_BITMAP_TEST(_field, _state, _test, _version, _field_size) { \ .name = (stringify(_field)), \ + .field_exists = (_test), \ .version_id = (_version), \ .size_offset = vmstate_offset_value(_state, _field_size, int32_t),\ .info = &vmstate_info_bitmap, \ @@ -XXX,XX +XXX,XX @@ extern const VMStateInfo vmstate_info_qlist; .offset = offsetof(_state, _field), \ } +#define VMSTATE_BITMAP(_field, _state, _version, _field_size) \ + VMSTATE_BITMAP_TEST(_field, _state, NULL, _version, _field_size) + /* For migrating a QTAILQ. * Target QTAILQ needs be properly initialized. * _type: type of QTAILQ element -- 2.39.1 From: David Hildenbrand <david@redhat.com> Let's factor out this check, to be used in virtio-mem context next. While at it, fix a spelling error in a related comment. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com>S Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- include/migration/misc.h | 4 +++- migration/migration.c | 7 +++++++ migration/ram.c | 8 +------- 3 files changed, 11 insertions(+), 8 deletions(-) diff --git a/include/migration/misc.h b/include/migration/misc.h index XXXXXXX..XXXXXXX 100644 --- a/include/migration/misc.h +++ b/include/migration/misc.h @@ -XXX,XX +XXX,XX @@ bool migration_has_failed(MigrationState *); /* ...and after the device transmission */ bool migration_in_postcopy_after_devices(MigrationState *); void migration_global_dump(Monitor *mon); -/* True if incomming migration entered POSTCOPY_INCOMING_DISCARD */ +/* True if incoming migration entered POSTCOPY_INCOMING_DISCARD */ bool migration_in_incoming_postcopy(void); +/* True if incoming migration entered POSTCOPY_INCOMING_ADVISE */ +bool migration_incoming_postcopy_advised(void); /* True if background snapshot is active */ bool migration_in_bg_snapshot(void); diff --git a/migration/migration.c b/migration/migration.c index XXXXXXX..XXXXXXX 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -XXX,XX +XXX,XX @@ bool migration_in_incoming_postcopy(void) return ps >= POSTCOPY_INCOMING_DISCARD && ps < POSTCOPY_INCOMING_END; } +bool migration_incoming_postcopy_advised(void) +{ + PostcopyState ps = postcopy_state_get(); + + return ps >= POSTCOPY_INCOMING_ADVISE && ps < POSTCOPY_INCOMING_END; +} + bool migration_in_bg_snapshot(void) { MigrationState *s = migrate_get_current(); diff --git a/migration/ram.c b/migration/ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -XXX,XX +XXX,XX @@ int ram_load_postcopy(QEMUFile *f, int channel) return ret; } -static bool postcopy_is_advised(void) -{ - PostcopyState ps = postcopy_state_get(); - return ps >= POSTCOPY_INCOMING_ADVISE && ps < POSTCOPY_INCOMING_END; -} - static bool postcopy_is_running(void) { PostcopyState ps = postcopy_state_get(); @@ -XXX,XX +XXX,XX @@ static int ram_load_precopy(QEMUFile *f) MigrationIncomingState *mis = migration_incoming_get_current(); int flags = 0, ret = 0, invalid_flags = 0, len = 0, i = 0; /* ADVISE is earlier, it shows the source has the postcopy capability on */ - bool postcopy_advised = postcopy_is_advised(); + bool postcopy_advised = migration_incoming_postcopy_advised(); if (!migrate_use_compression()) { invalid_flags |= RAM_SAVE_FLAG_COMPRESS_PAGE; } -- 2.39.1 From: David Hildenbrand <david@redhat.com> "prealloc=on" for the memory backend does not work as expected, as virtio-mem will simply discard all preallocated memory immediately again. In the best case, it's an expensive NOP. In the worst case, it's an unexpected allocation error. Instead, "prealloc=on" should be specified for the virtio-mem device only, such that virtio-mem will try preallocating memory before plugging memory dynamically to the guest. Fail if such a memory backend is provided. Tested-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com>S Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- hw/virtio/virtio-mem.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index XXXXXXX..XXXXXXX 100644 --- a/hw/virtio/virtio-mem.c +++ b/hw/virtio/virtio-mem.c @@ -XXX,XX +XXX,XX @@ static void virtio_mem_device_realize(DeviceState *dev, Error **errp) error_setg(errp, "'%s' property specifies an unsupported memdev", VIRTIO_MEM_MEMDEV_PROP); return; + } else if (vmem->memdev->prealloc) { + error_setg(errp, "'%s' property specifies a memdev with preallocation" + " enabled: %s. Instead, specify 'prealloc=on' for the" + " virtio-mem device. ", VIRTIO_MEM_MEMDEV_PROP, + object_get_canonical_path_component(OBJECT(vmem->memdev))); + return; } if ((nb_numa_nodes && vmem->node >= nb_numa_nodes) || -- 2.39.1 From: David Hildenbrand <david@redhat.com> The bitmap and the size are immutable while migration is active: see virtio_mem_is_busy(). We can migrate this information early, before migrating any actual RAM content. Further, all information we need for sanity checks is immutable as well. Having this information in place early will, for example, allow for properly preallocating memory before touching these memory locations during RAM migration: this way, we can make sure that all memory was actually preallocated and that any user errors (e.g., insufficient hugetlb pages) can be handled gracefully. In contrast, usable_region_size and requested_size can theoretically still be modified on the source while the VM is running. Keep migrating these properties the usual, late, way. Use a new device property to keep behavior of compat machines unmodified. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com>S Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- include/hw/virtio/virtio-mem.h | 8 ++++++ hw/core/machine.c | 4 ++- hw/virtio/virtio-mem.c | 51 ++++++++++++++++++++++++++++++++-- 3 files changed, 60 insertions(+), 3 deletions(-) diff --git a/include/hw/virtio/virtio-mem.h b/include/hw/virtio/virtio-mem.h index XXXXXXX..XXXXXXX 100644 --- a/include/hw/virtio/virtio-mem.h +++ b/include/hw/virtio/virtio-mem.h @@ -XXX,XX +XXX,XX @@ OBJECT_DECLARE_TYPE(VirtIOMEM, VirtIOMEMClass, #define VIRTIO_MEM_BLOCK_SIZE_PROP "block-size" #define VIRTIO_MEM_ADDR_PROP "memaddr" #define VIRTIO_MEM_UNPLUGGED_INACCESSIBLE_PROP "unplugged-inaccessible" +#define VIRTIO_MEM_EARLY_MIGRATION_PROP "x-early-migration" #define VIRTIO_MEM_PREALLOC_PROP "prealloc" struct VirtIOMEM { @@ -XXX,XX +XXX,XX @@ struct VirtIOMEM { /* whether to prealloc memory when plugging new blocks */ bool prealloc; + /* + * Whether we migrate properties that are immutable while migration is + * active early, before state of other devices and especially, before + * migrating any RAM content. + */ + bool early_migration; + /* notifiers to notify when "size" changes */ NotifierList size_change_notifiers; diff --git a/hw/core/machine.c b/hw/core/machine.c index XXXXXXX..XXXXXXX 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -XXX,XX +XXX,XX @@ #include "hw/virtio/virtio-pci.h" #include "qom/object_interfaces.h" -GlobalProperty hw_compat_7_2[] = {}; +GlobalProperty hw_compat_7_2[] = { + { "virtio-mem", "x-early-migration", "false" }, +}; const size_t hw_compat_7_2_len = G_N_ELEMENTS(hw_compat_7_2); GlobalProperty hw_compat_7_1[] = { diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index XXXXXXX..XXXXXXX 100644 --- a/hw/virtio/virtio-mem.c +++ b/hw/virtio/virtio-mem.c @@ -XXX,XX +XXX,XX @@ #include CONFIG_DEVICES #include "trace.h" +static const VMStateDescription vmstate_virtio_mem_device_early; + /* * We only had legacy x86 guests that did not support * VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE. Other targets don't have legacy guests. @@ -XXX,XX +XXX,XX @@ static void virtio_mem_device_realize(DeviceState *dev, Error **errp) host_memory_backend_set_mapped(vmem->memdev, true); vmstate_register_ram(&vmem->memdev->mr, DEVICE(vmem)); + if (vmem->early_migration) { + vmstate_register(VMSTATE_IF(vmem), VMSTATE_INSTANCE_ID_ANY, + &vmstate_virtio_mem_device_early, vmem); + } qemu_register_reset(virtio_mem_system_reset, vmem); /* @@ -XXX,XX +XXX,XX @@ static void virtio_mem_device_unrealize(DeviceState *dev) */ memory_region_set_ram_discard_manager(&vmem->memdev->mr, NULL); qemu_unregister_reset(virtio_mem_system_reset, vmem); + if (vmem->early_migration) { + vmstate_unregister(VMSTATE_IF(vmem), &vmstate_virtio_mem_device_early, + vmem); + } vmstate_unregister_ram(&vmem->memdev->mr, DEVICE(vmem)); host_memory_backend_set_mapped(vmem->memdev, false); virtio_del_queue(vdev, 0); @@ -XXX,XX +XXX,XX @@ static const VMStateDescription vmstate_virtio_mem_sanity_checks = { }, }; +static bool virtio_mem_vmstate_field_exists(void *opaque, int version_id) +{ + const VirtIOMEM *vmem = VIRTIO_MEM(opaque); + + /* With early migration, these fields were already migrated. */ + return !vmem->early_migration; +} + static const VMStateDescription vmstate_virtio_mem_device = { .name = "virtio-mem-device", .minimum_version_id = 1, .version_id = 1, .priority = MIG_PRI_VIRTIO_MEM, .post_load = virtio_mem_post_load, + .fields = (VMStateField[]) { + VMSTATE_WITH_TMP_TEST(VirtIOMEM, virtio_mem_vmstate_field_exists, + VirtIOMEMMigSanityChecks, + vmstate_virtio_mem_sanity_checks), + VMSTATE_UINT64(usable_region_size, VirtIOMEM), + VMSTATE_UINT64_TEST(size, VirtIOMEM, virtio_mem_vmstate_field_exists), + VMSTATE_UINT64(requested_size, VirtIOMEM), + VMSTATE_BITMAP_TEST(bitmap, VirtIOMEM, virtio_mem_vmstate_field_exists, + 0, bitmap_size), + VMSTATE_END_OF_LIST() + }, +}; + +/* + * Transfer properties that are immutable while migration is active early, + * such that we have have this information around before migrating any RAM + * content. + * + * Note that virtio_mem_is_busy() makes sure these properties can no longer + * change on the migration source until migration completed. + * + * With QEMU compat machines, we transmit these properties later, via + * vmstate_virtio_mem_device instead -- see virtio_mem_vmstate_field_exists(). + */ +static const VMStateDescription vmstate_virtio_mem_device_early = { + .name = "virtio-mem-device-early", + .minimum_version_id = 1, + .version_id = 1, + .early_setup = true, .fields = (VMStateField[]) { VMSTATE_WITH_TMP(VirtIOMEM, VirtIOMEMMigSanityChecks, vmstate_virtio_mem_sanity_checks), - VMSTATE_UINT64(usable_region_size, VirtIOMEM), VMSTATE_UINT64(size, VirtIOMEM), - VMSTATE_UINT64(requested_size, VirtIOMEM), VMSTATE_BITMAP(bitmap, VirtIOMEM, 0, bitmap_size), VMSTATE_END_OF_LIST() }, @@ -XXX,XX +XXX,XX @@ static Property virtio_mem_properties[] = { DEFINE_PROP_ON_OFF_AUTO(VIRTIO_MEM_UNPLUGGED_INACCESSIBLE_PROP, VirtIOMEM, unplugged_inaccessible, ON_OFF_AUTO_AUTO), #endif + DEFINE_PROP_BOOL(VIRTIO_MEM_EARLY_MIGRATION_PROP, VirtIOMEM, + early_migration, true), DEFINE_PROP_END_OF_LIST(), }; -- 2.39.1 From: David Hildenbrand <david@redhat.com> Ordinary memory preallocation runs when QEMU starts up and creates the memory backends, before processing the incoming migration stream. With virtio-mem, we don't know which memory blocks to preallocate before migration started. Now that we migrate the virtio-mem bitmap early, before migrating any RAM content, we can safely preallocate memory for all plugged memory blocks before migrating any RAM content. This is especially relevant for the following cases: (1) User errors With hugetlb/files, if we don't have sufficient backend memory available on the migration destination, we'll crash QEMU (SIGBUS) during RAM migration when running out of backend memory. Preallocating memory before actual RAM migration allows for failing gracefully and informing the user about the setup problem. (2) Excluded memory ranges during migration For example, virtio-balloon free page hinting will exclude some pages from getting migrated. In that case, we won't crash during RAM migration, but later, when running the VM on the destination, which is bad. To fix this for new QEMU machines that migrate the bitmap early, preallocate the memory early, before any RAM migration. Warn with old QEMU machines. Getting postcopy right is a bit tricky, but we essentially now implement the same (problematic) preallocation logic as ordinary preallocation: preallocate memory early and discard it again before precopy starts. During ordinary preallocation, discarding of RAM happens when postcopy is advised. As the state (bitmap) is loaded after postcopy was advised but before postcopy starts listening, we have to discard memory we preallocated immediately again ourselves. Note that nothing (not even hugetlb reservations) guarantees for postcopy that backend memory (especially, hugetlb pages) are still free after they were freed ones while discarding RAM. Still, allocating that memory at least once helps catching some basic setup problems. Before this change, trying to restore a VM when insufficient hugetlb pages are around results in the process crashing to to a "Bus error" (SIGBUS). With this change, QEMU fails gracefully: qemu-system-x86_64: qemu_prealloc_mem: preallocating memory failed: Bad address qemu-system-x86_64: error while loading state for instance 0x0 of device '0000:00:03.0/virtio-mem-device-early' qemu-system-x86_64: load of migration failed: Cannot allocate memory And we can even introspect the early migration data, including the bitmap: $ ./scripts/analyze-migration.py -f STATEFILE { "ram (2)": { "section sizes": { "0000:00:03.0/mem0": "0x0000000780000000", "0000:00:04.0/mem1": "0x0000000780000000", "pc.ram": "0x0000000100000000", "/rom@etc/acpi/tables": "0x0000000000020000", "pc.bios": "0x0000000000040000", "0000:00:02.0/e1000.rom": "0x0000000000040000", "pc.rom": "0x0000000000020000", "/rom@etc/table-loader": "0x0000000000001000", "/rom@etc/acpi/rsdp": "0x0000000000001000" } }, "0000:00:03.0/virtio-mem-device-early (51)": { "tmp": "00 00 00 01 40 00 00 00 00 00 00 07 80 00 00 00 00 00 00 00 00 20 00 00 00 00 00 00", "size": "0x0000000040000000", "bitmap": "ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [...] }, "0000:00:04.0/virtio-mem-device-early (53)": { "tmp": "00 00 00 08 c0 00 00 00 00 00 00 07 80 00 00 00 00 00 00 00 00 20 00 00 00 00 00 00", "size": "0x00000001fa400000", "bitmap": "ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [...] }, [...] Reported-by: Jing Qi <jinqi@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com>S Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- hw/virtio/virtio-mem.c | 87 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index XXXXXXX..XXXXXXX 100644 --- a/hw/virtio/virtio-mem.c +++ b/hw/virtio/virtio-mem.c @@ -XXX,XX +XXX,XX @@ static int virtio_mem_for_each_unplugged_range(const VirtIOMEM *vmem, void *arg, return ret; } +static int virtio_mem_for_each_plugged_range(const VirtIOMEM *vmem, void *arg, + virtio_mem_range_cb cb) +{ + unsigned long first_bit, last_bit; + uint64_t offset, size; + int ret = 0; + + first_bit = find_first_bit(vmem->bitmap, vmem->bitmap_size); + while (first_bit < vmem->bitmap_size) { + offset = first_bit * vmem->block_size; + last_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size, + first_bit + 1) - 1; + size = (last_bit - first_bit + 1) * vmem->block_size; + + ret = cb(vmem, arg, offset, size); + if (ret) { + break; + } + first_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size, + last_bit + 2); + } + return ret; +} + /* * Adjust the memory section to cover the intersection with the given range. * @@ -XXX,XX +XXX,XX @@ static int virtio_mem_post_load(void *opaque, int version_id) RamDiscardListener *rdl; int ret; + if (vmem->prealloc && !vmem->early_migration) { + warn_report("Proper preallocation with migration requires a newer QEMU machine"); + } + /* * We started out with all memory discarded and our memory region is mapped * into an address space. Replay, now that we updated the bitmap. @@ -XXX,XX +XXX,XX @@ static int virtio_mem_post_load(void *opaque, int version_id) return virtio_mem_restore_unplugged(vmem); } +static int virtio_mem_prealloc_range_cb(const VirtIOMEM *vmem, void *arg, + uint64_t offset, uint64_t size) +{ + void *area = memory_region_get_ram_ptr(&vmem->memdev->mr) + offset; + int fd = memory_region_get_fd(&vmem->memdev->mr); + Error *local_err = NULL; + + qemu_prealloc_mem(fd, area, size, 1, NULL, &local_err); + if (local_err) { + error_report_err(local_err); + return -ENOMEM; + } + return 0; +} + +static int virtio_mem_post_load_early(void *opaque, int version_id) +{ + VirtIOMEM *vmem = VIRTIO_MEM(opaque); + RAMBlock *rb = vmem->memdev->mr.ram_block; + int ret; + + if (!vmem->prealloc) { + return 0; + } + + /* + * We restored the bitmap and verified that the basic properties + * match on source and destination, so we can go ahead and preallocate + * memory for all plugged memory blocks, before actual RAM migration starts + * touching this memory. + */ + ret = virtio_mem_for_each_plugged_range(vmem, NULL, + virtio_mem_prealloc_range_cb); + if (ret) { + return ret; + } + + /* + * This is tricky: postcopy wants to start with a clean slate. On + * POSTCOPY_INCOMING_ADVISE, postcopy code discards all (ordinarily + * preallocated) RAM such that postcopy will work as expected later. + * + * However, we run after POSTCOPY_INCOMING_ADVISE -- but before actual + * RAM migration. So let's discard all memory again. This looks like an + * expensive NOP, but actually serves a purpose: we made sure that we + * were able to allocate all required backend memory once. We cannot + * guarantee that the backend memory we will free will remain free + * until we need it during postcopy, but at least we can catch the + * obvious setup issues this way. + */ + if (migration_incoming_postcopy_advised()) { + if (ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb))) { + return -EBUSY; + } + } + return 0; +} + typedef struct VirtIOMEMMigSanityChecks { VirtIOMEM *parent; uint64_t addr; @@ -XXX,XX +XXX,XX @@ static const VMStateDescription vmstate_virtio_mem_device_early = { .minimum_version_id = 1, .version_id = 1, .early_setup = true, + .post_load = virtio_mem_post_load_early, .fields = (VMStateField[]) { VMSTATE_WITH_TMP(VirtIOMEM, VirtIOMEMMigSanityChecks, vmstate_virtio_mem_sanity_checks), -- 2.39.1 From: Peter Xu <peterx@redhat.com> The downtime should be displayed during postcopy phase because the switchover phase is done. OTOH it's weird to show "expected downtime" which can confuse what does that mean if the switchover has already happened anyway. This is a slight ABI change on QMP, but I assume it shouldn't affect anyone. Reviewed-by: Leonardo Bras <leobras@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/migration.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index XXXXXXX..XXXXXXX 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -XXX,XX +XXX,XX @@ bool migration_is_running(int state) } } +static bool migrate_show_downtime(MigrationState *s) +{ + return (s->state == MIGRATION_STATUS_COMPLETED) || migration_in_postcopy(); +} + static void populate_time_info(MigrationInfo *info, MigrationState *s) { info->has_status = true; info->has_setup_time = true; info->setup_time = s->setup_time; + if (s->state == MIGRATION_STATUS_COMPLETED) { info->has_total_time = true; info->total_time = s->total_time; - info->has_downtime = true; - info->downtime = s->downtime; } else { info->has_total_time = true; info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - s->start_time; + } + + if (migrate_show_downtime(s)) { + info->has_downtime = true; + info->downtime = s->downtime; + } else { info->has_expected_downtime = true; info->expected_downtime = s->expected_downtime; } -- 2.39.1 From: Fiona Ebner <f.ebner@proxmox.com> upon errors. As the documentation in include/io/channel.h states, only -1 and QIO_CHANNEL_ERR_BLOCK should be returned upon error. Other values have the potential to confuse the call sites. error_setg is used rather than error_setg_errno, because there are certain code paths where -1 (as a non-errno) is propagated up (e.g. starting from qemu_rdma_block_for_wrid or qemu_rdma_post_recv_control) all the way to qio_channel_rdma_{readv,writev}. Similar to a216ec85b7 ("migration/channel-block: fix return value for qio_channel_block_{readv,writev}"). Suggested-by: Zhang Chen <chen.zhang@intel.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Fiona Ebner <f.ebner@proxmox.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/rdma.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/migration/rdma.c b/migration/rdma.c index XXXXXXX..XXXXXXX 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc, rdma = qatomic_rcu_read(&rioc->rdmaout); if (!rdma) { - return -EIO; + error_setg(errp, "RDMA control channel output is not set"); + return -1; } CHECK_ERROR_STATE(); @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc, ret = qemu_rdma_write_flush(f, rdma); if (ret < 0) { rdma->error_state = ret; - return ret; + error_setg(errp, "qemu_rdma_write_flush returned %d", ret); + return -1; } for (i = 0; i < niov; i++) { @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc, if (ret < 0) { rdma->error_state = ret; - return ret; + error_setg(errp, "qemu_rdma_exchange_send returned %d", ret); + return -1; } data += len; @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_rdma_readv(QIOChannel *ioc, rdma = qatomic_rcu_read(&rioc->rdmain); if (!rdma) { - return -EIO; + error_setg(errp, "RDMA control channel input is not set"); + return -1; } CHECK_ERROR_STATE(); @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_rdma_readv(QIOChannel *ioc, if (ret < 0) { rdma->error_state = ret; - return ret; + error_setg(errp, "qemu_rdma_exchange_recv returned %d", ret); + return -1; } /* -- 2.39.1 From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> We fairly regularly forget VMSTATE_END_OF_LIST markers off descriptions; given that the current check is only for ->name being NULL, sometimes we get unlucky and the code apparently works and no one spots the error. Explicitly add a flag, VMS_END that should be set, and assert it is set during the traversal. Note: This can't go in until we update the copy of vmstate.h in slirp. Suggested-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- include/migration/vmstate.h | 7 ++++++- migration/savevm.c | 1 + migration/vmstate.c | 2 ++ 3 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index XXXXXXX..XXXXXXX 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -XXX,XX +XXX,XX @@ enum VMStateFlags { * VMStateField.struct_version_id to tell which version of the * structure we are referencing to use. */ VMS_VSTRUCT = 0x8000, + + /* Marker for end of list */ + VMS_END = 0x10000 }; typedef enum { @@ -XXX,XX +XXX,XX @@ extern const VMStateInfo vmstate_info_qlist; VMSTATE_UNUSED_BUFFER(_test, 0, _size) #define VMSTATE_END_OF_LIST() \ - {} + { \ + .flags = VMS_END, \ + } int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, void *opaque, int version_id); diff --git a/migration/savevm.c b/migration/savevm.c index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -XXX,XX +XXX,XX @@ static void dump_vmstate_vmsd(FILE *out_file, field++; first = false; } + assert(field->flags == VMS_END); fprintf(out_file, "\n%*s]", indent, ""); } if (vmsd->subsections != NULL) { diff --git a/migration/vmstate.c b/migration/vmstate.c index XXXXXXX..XXXXXXX 100644 --- a/migration/vmstate.c +++ b/migration/vmstate.c @@ -XXX,XX +XXX,XX @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, } field++; } + assert(field->flags == VMS_END); ret = vmstate_subsection_load(f, vmsd, opaque); if (ret != 0) { return ret; @@ -XXX,XX +XXX,XX @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd, } field++; } + assert(field->flags == VMS_END); if (vmdesc) { json_writer_end_array(vmdesc); -- 2.39.1 From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Perform a check on vmsd structures during test runs in the hope of catching any missing terminators and other simple screwups. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/savevm.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/migration/savevm.c b/migration/savevm.c index XXXXXXX..XXXXXXX 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -XXX,XX +XXX,XX @@ #include "net/announce.h" #include "qemu/yank.h" #include "yank_functions.h" +#include "sysemu/qtest.h" const unsigned int postcopy_ram_discard_version; @@ -XXX,XX +XXX,XX @@ void unregister_savevm(VMStateIf *obj, const char *idstr, void *opaque) } } +/* + * Perform some basic checks on vmsd's at registration + * time. + */ +static void vmstate_check(const VMStateDescription *vmsd) +{ + const VMStateField *field = vmsd->fields; + const VMStateDescription **subsection = vmsd->subsections; + + if (field) { + while (field->name) { + if (field->flags & (VMS_STRUCT | VMS_VSTRUCT)) { + /* Recurse to sub structures */ + vmstate_check(field->vmsd); + } + /* Carry on */ + field++; + } + /* Check for the end of field list canary */ + if (field->flags != VMS_END) { + error_report("VMSTATE not ending with VMS_END: %s", vmsd->name); + g_assert_not_reached(); + } + } + + while (subsection && *subsection) { + /* + * The name of a subsection should start with the name of the + * current object. + */ + assert(!strncmp(vmsd->name, (*subsection)->name, strlen(vmsd->name))); + vmstate_check(*subsection); + subsection++; + } +} + int vmstate_register_with_alias_id(VMStateIf *obj, uint32_t instance_id, const VMStateDescription *vmsd, void *opaque, int alias_id, @@ -XXX,XX +XXX,XX @@ int vmstate_register_with_alias_id(VMStateIf *obj, uint32_t instance_id, } else { se->instance_id = instance_id; } + + /* Perform a recursive sanity check during the test runs */ + if (qtest_enabled()) { + vmstate_check(vmsd); + } assert(!se->compat || se->instance_id == 0); savevm_state_handler_insert(se); return 0; -- 2.39.1 From: Zhenzhong Duan <zhenzhong.duan@intel.com> The value of "Sample Pages" is confusing in mode other than page-sampling. See below: (qemu) calc_dirty_rate -b 10 520 (qemu) info dirty_rate Status: measuring Start Time: 11646834 (ms) Sample Pages: 520 (per GB) Period: 10 (sec) Mode: dirty-bitmap Dirty rate: (not ready) (qemu) info dirty_rate Status: measured Start Time: 11646834 (ms) Sample Pages: 0 (per GB) Period: 10 (sec) Mode: dirty-bitmap Dirty rate: 2 (MB/s) While it's totally useless in dirty-ring and dirty-bitmap mode, fix to show it only in page-sampling mode. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/dirtyrate.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c index XXXXXXX..XXXXXXX 100644 --- a/migration/dirtyrate.c +++ b/migration/dirtyrate.c @@ -XXX,XX +XXX,XX @@ void qmp_calc_dirty_rate(int64_t calc_time, mode = DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING; } - if (has_sample_pages && mode == DIRTY_RATE_MEASURE_MODE_DIRTY_RING) { - error_setg(errp, "either sample-pages or dirty-ring can be specified."); + if (has_sample_pages && mode != DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING) { + error_setg(errp, "sample-pages is used only in page-sampling mode"); return; } @@ -XXX,XX +XXX,XX @@ void hmp_info_dirty_rate(Monitor *mon, const QDict *qdict) DirtyRateStatus_str(info->status)); monitor_printf(mon, "Start Time: %"PRIi64" (ms)\n", info->start_time); - monitor_printf(mon, "Sample Pages: %"PRIu64" (per GB)\n", - info->sample_pages); + if (info->mode == DIRTY_RATE_MEASURE_MODE_PAGE_SAMPLING) { + monitor_printf(mon, "Sample Pages: %"PRIu64" (per GB)\n", + info->sample_pages); + } monitor_printf(mon, "Period: %"PRIi64" (sec)\n", info->calc_time); monitor_printf(mon, "Mode: %s\n", -- 2.39.1 From: "manish.mishra" <manish.mishra@nutanix.com> MSG_PEEK peeks at the channel, The data is treated as unread and the next read shall still return this data. This support is currently added only for socket class. Extra parameter 'flags' is added to io_readv calls to pass extra read flags like MSG_PEEK. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Suggested-by: Daniel P. Berrange <berrange@redhat.com> Signed-off-by: manish.mishra <manish.mishra@nutanix.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- include/io/channel.h | 6 ++++++ chardev/char-socket.c | 4 ++-- io/channel-buffer.c | 1 + io/channel-command.c | 1 + io/channel-file.c | 1 + io/channel-null.c | 1 + io/channel-socket.c | 19 ++++++++++++++++++- io/channel-tls.c | 1 + io/channel-websock.c | 1 + io/channel.c | 16 ++++++++++++---- migration/channel-block.c | 1 + migration/rdma.c | 1 + scsi/qemu-pr-helper.c | 2 +- tests/qtest/tpm-emu.c | 2 +- tests/unit/test-io-channel-socket.c | 1 + util/vhost-user-server.c | 2 +- 16 files changed, 50 insertions(+), 10 deletions(-) diff --git a/include/io/channel.h b/include/io/channel.h index XXXXXXX..XXXXXXX 100644 --- a/include/io/channel.h +++ b/include/io/channel.h @@ -XXX,XX +XXX,XX @@ OBJECT_DECLARE_TYPE(QIOChannel, QIOChannelClass, #define QIO_CHANNEL_WRITE_FLAG_ZERO_COPY 0x1 +#define QIO_CHANNEL_READ_FLAG_MSG_PEEK 0x1 + typedef enum QIOChannelFeature QIOChannelFeature; enum QIOChannelFeature { @@ -XXX,XX +XXX,XX @@ enum QIOChannelFeature { QIO_CHANNEL_FEATURE_SHUTDOWN, QIO_CHANNEL_FEATURE_LISTEN, QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY, + QIO_CHANNEL_FEATURE_READ_MSG_PEEK, }; @@ -XXX,XX +XXX,XX @@ struct QIOChannelClass { size_t niov, int **fds, size_t *nfds, + int flags, Error **errp); int (*io_close)(QIOChannel *ioc, Error **errp); @@ -XXX,XX +XXX,XX @@ void qio_channel_set_name(QIOChannel *ioc, * @niov: the length of the @iov array * @fds: pointer to an array that will received file handles * @nfds: pointer filled with number of elements in @fds on return + * @flags: read flags (QIO_CHANNEL_READ_FLAG_*) * @errp: pointer to a NULL-initialized error object * * Read data from the IO channel, storing it in the @@ -XXX,XX +XXX,XX @@ ssize_t qio_channel_readv_full(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp); diff --git a/chardev/char-socket.c b/chardev/char-socket.c index XXXXXXX..XXXXXXX 100644 --- a/chardev/char-socket.c +++ b/chardev/char-socket.c @@ -XXX,XX +XXX,XX @@ static ssize_t tcp_chr_recv(Chardev *chr, char *buf, size_t len) if (qio_channel_has_feature(s->ioc, QIO_CHANNEL_FEATURE_FD_PASS)) { ret = qio_channel_readv_full(s->ioc, &iov, 1, &msgfds, &msgfds_num, - NULL); + 0, NULL); } else { ret = qio_channel_readv_full(s->ioc, &iov, 1, NULL, NULL, - NULL); + 0, NULL); } if (msgfds_num) { diff --git a/io/channel-buffer.c b/io/channel-buffer.c index XXXXXXX..XXXXXXX 100644 --- a/io/channel-buffer.c +++ b/io/channel-buffer.c @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_buffer_readv(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp) { QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc); diff --git a/io/channel-command.c b/io/channel-command.c index XXXXXXX..XXXXXXX 100644 --- a/io/channel-command.c +++ b/io/channel-command.c @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_command_readv(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp) { QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc); diff --git a/io/channel-file.c b/io/channel-file.c index XXXXXXX..XXXXXXX 100644 --- a/io/channel-file.c +++ b/io/channel-file.c @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_file_readv(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp) { QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); diff --git a/io/channel-null.c b/io/channel-null.c index XXXXXXX..XXXXXXX 100644 --- a/io/channel-null.c +++ b/io/channel-null.c @@ -XXX,XX +XXX,XX @@ qio_channel_null_readv(QIOChannel *ioc, size_t niov, int **fds G_GNUC_UNUSED, size_t *nfds G_GNUC_UNUSED, + int flags, Error **errp) { QIOChannelNull *nioc = QIO_CHANNEL_NULL(ioc); diff --git a/io/channel-socket.c b/io/channel-socket.c index XXXXXXX..XXXXXXX 100644 --- a/io/channel-socket.c +++ b/io/channel-socket.c @@ -XXX,XX +XXX,XX @@ int qio_channel_socket_connect_sync(QIOChannelSocket *ioc, } #endif + qio_channel_set_feature(QIO_CHANNEL(ioc), + QIO_CHANNEL_FEATURE_READ_MSG_PEEK); + return 0; } @@ -XXX,XX +XXX,XX @@ qio_channel_socket_accept(QIOChannelSocket *ioc, } #endif /* WIN32 */ + qio_channel_set_feature(QIO_CHANNEL(cioc), + QIO_CHANNEL_FEATURE_READ_MSG_PEEK); + trace_qio_channel_socket_accept_complete(ioc, cioc, cioc->fd); return cioc; @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_socket_readv(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp) { QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc); @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_socket_readv(QIOChannel *ioc, } + if (flags & QIO_CHANNEL_READ_FLAG_MSG_PEEK) { + sflags |= MSG_PEEK; + } + retry: ret = recvmsg(sioc->fd, &msg, sflags); if (ret < 0) { @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_socket_readv(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp) { QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc); ssize_t done = 0; ssize_t i; + int sflags = 0; + + if (flags & QIO_CHANNEL_READ_FLAG_MSG_PEEK) { + sflags |= MSG_PEEK; + } for (i = 0; i < niov; i++) { ssize_t ret; @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_socket_readv(QIOChannel *ioc, ret = recv(sioc->fd, iov[i].iov_base, iov[i].iov_len, - 0); + sflags); if (ret < 0) { if (errno == EAGAIN) { if (done) { diff --git a/io/channel-tls.c b/io/channel-tls.c index XXXXXXX..XXXXXXX 100644 --- a/io/channel-tls.c +++ b/io/channel-tls.c @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_tls_readv(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp) { QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc); diff --git a/io/channel-websock.c b/io/channel-websock.c index XXXXXXX..XXXXXXX 100644 --- a/io/channel-websock.c +++ b/io/channel-websock.c @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_websock_readv(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp) { QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc); diff --git a/io/channel.c b/io/channel.c index XXXXXXX..XXXXXXX 100644 --- a/io/channel.c +++ b/io/channel.c @@ -XXX,XX +XXX,XX @@ ssize_t qio_channel_readv_full(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp) { QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); @@ -XXX,XX +XXX,XX @@ ssize_t qio_channel_readv_full(QIOChannel *ioc, return -1; } - return klass->io_readv(ioc, iov, niov, fds, nfds, errp); + if ((flags & QIO_CHANNEL_READ_FLAG_MSG_PEEK) && + !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_READ_MSG_PEEK)) { + error_setg_errno(errp, EINVAL, + "Channel does not support peek read"); + return -1; + } + + return klass->io_readv(ioc, iov, niov, fds, nfds, flags, errp); } @@ -XXX,XX +XXX,XX @@ int qio_channel_readv_full_all_eof(QIOChannel *ioc, while ((nlocal_iov > 0) || local_fds) { ssize_t len; len = qio_channel_readv_full(ioc, local_iov, nlocal_iov, local_fds, - local_nfds, errp); + local_nfds, 0, errp); if (len == QIO_CHANNEL_ERR_BLOCK) { if (qemu_in_coroutine()) { qio_channel_yield(ioc, G_IO_IN); @@ -XXX,XX +XXX,XX @@ ssize_t qio_channel_readv(QIOChannel *ioc, size_t niov, Error **errp) { - return qio_channel_readv_full(ioc, iov, niov, NULL, NULL, errp); + return qio_channel_readv_full(ioc, iov, niov, NULL, NULL, 0, errp); } @@ -XXX,XX +XXX,XX @@ ssize_t qio_channel_read(QIOChannel *ioc, Error **errp) { struct iovec iov = { .iov_base = buf, .iov_len = buflen }; - return qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, errp); + return qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, 0, errp); } diff --git a/migration/channel-block.c b/migration/channel-block.c index XXXXXXX..XXXXXXX 100644 --- a/migration/channel-block.c +++ b/migration/channel-block.c @@ -XXX,XX +XXX,XX @@ qio_channel_block_readv(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp) { QIOChannelBlock *bioc = QIO_CHANNEL_BLOCK(ioc); diff --git a/migration/rdma.c b/migration/rdma.c index XXXXXXX..XXXXXXX 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -XXX,XX +XXX,XX @@ static ssize_t qio_channel_rdma_readv(QIOChannel *ioc, size_t niov, int **fds, size_t *nfds, + int flags, Error **errp) { QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(ioc); diff --git a/scsi/qemu-pr-helper.c b/scsi/qemu-pr-helper.c index XXXXXXX..XXXXXXX 100644 --- a/scsi/qemu-pr-helper.c +++ b/scsi/qemu-pr-helper.c @@ -XXX,XX +XXX,XX @@ static int coroutine_fn prh_read(PRHelperClient *client, void *buf, int sz, iov.iov_base = buf; iov.iov_len = sz; n_read = qio_channel_readv_full(QIO_CHANNEL(client->ioc), &iov, 1, - &fds, &nfds, errp); + &fds, &nfds, 0, errp); if (n_read == QIO_CHANNEL_ERR_BLOCK) { qio_channel_yield(QIO_CHANNEL(client->ioc), G_IO_IN); diff --git a/tests/qtest/tpm-emu.c b/tests/qtest/tpm-emu.c index XXXXXXX..XXXXXXX 100644 --- a/tests/qtest/tpm-emu.c +++ b/tests/qtest/tpm-emu.c @@ -XXX,XX +XXX,XX @@ void *tpm_emu_ctrl_thread(void *data) int *pfd = NULL; size_t nfd = 0; - qio_channel_readv_full(ioc, &iov, 1, &pfd, &nfd, &error_abort); + qio_channel_readv_full(ioc, &iov, 1, &pfd, &nfd, 0, &error_abort); cmd = be32_to_cpu(cmd); g_assert_cmpint(cmd, ==, CMD_SET_DATAFD); g_assert_cmpint(nfd, ==, 1); diff --git a/tests/unit/test-io-channel-socket.c b/tests/unit/test-io-channel-socket.c index XXXXXXX..XXXXXXX 100644 --- a/tests/unit/test-io-channel-socket.c +++ b/tests/unit/test-io-channel-socket.c @@ -XXX,XX +XXX,XX @@ static void test_io_channel_unix_fd_pass(void) G_N_ELEMENTS(iorecv), &fdrecv, &nfdrecv, + 0, &error_abort); g_assert(nfdrecv == G_N_ELEMENTS(fdsend)); 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) * 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, &nfds, &local_err); + rc = qio_channel_readv_full(ioc, &iov, 1, &fds, &nfds, 0, &local_err); if (rc < 0) { if (rc == QIO_CHANNEL_ERR_BLOCK) { assert(local_err == NULL); -- 2.39.1 From: "manish.mishra" <manish.mishra@nutanix.com> Current logic assumes that channel connections on the destination side are always established in the same order as the source and the first one will always be the main channel followed by the multifid or post-copy preemption channel. This may not be always true, as even if a channel has a connection established on the source side it can be in the pending state on the destination side and a newer connection can be established first. Basically causing out of order mapping of channels on the destination side. Currently, all channels except post-copy preempt send a magic number, this patch uses that magic number to decide the type of channel. This logic is applicable only for precopy(multifd) live migration, as mentioned, the post-copy preempt channel does not send any magic number. Also, tls live migrations already does tls handshake before creating other channels, so this issue is not possible with tls, hence this logic is avoided for tls live migrations. This patch uses read peek to check the magic number of channels so that current data/control stream management remains un-effected. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Suggested-by: Daniel P. Berrange <berrange@redhat.com> Signed-off-by: manish.mishra <manish.mishra@nutanix.com> Signed-off-by: Juan Quintela <quintela@redhat.com> --- migration/channel.h | 5 ++++ migration/multifd.h | 2 +- migration/postcopy-ram.h | 2 +- migration/channel.c | 45 +++++++++++++++++++++++++++++++++ migration/migration.c | 54 ++++++++++++++++++++++++++++------------ migration/multifd.c | 19 +++++++------- migration/postcopy-ram.c | 5 +--- 7 files changed, 101 insertions(+), 31 deletions(-) diff --git a/migration/channel.h b/migration/channel.h index XXXXXXX..XXXXXXX 100644 --- a/migration/channel.h +++ b/migration/channel.h @@ -XXX,XX +XXX,XX @@ void migration_channel_connect(MigrationState *s, QIOChannel *ioc, const char *hostname, Error *error_in); + +int migration_channel_read_peek(QIOChannel *ioc, + const char *buf, + const size_t buflen, + Error **errp); #endif diff --git a/migration/multifd.h b/migration/multifd.h index XXXXXXX..XXXXXXX 100644 --- a/migration/multifd.h +++ b/migration/multifd.h @@ -XXX,XX +XXX,XX @@ void multifd_save_cleanup(void); int multifd_load_setup(Error **errp); int multifd_load_cleanup(Error **errp); bool multifd_recv_all_channels_created(void); -bool multifd_recv_new_channel(QIOChannel *ioc, Error **errp); +void multifd_recv_new_channel(QIOChannel *ioc, Error **errp); void multifd_recv_sync_main(void); int multifd_send_sync_main(QEMUFile *f); int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset); diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h index XXXXXXX..XXXXXXX 100644 --- a/migration/postcopy-ram.h +++ b/migration/postcopy-ram.h @@ -XXX,XX +XXX,XX @@ enum PostcopyChannels { RAM_CHANNEL_MAX, }; -bool postcopy_preempt_new_channel(MigrationIncomingState *mis, QEMUFile *file); +void postcopy_preempt_new_channel(MigrationIncomingState *mis, QEMUFile *file); int postcopy_preempt_setup(MigrationState *s, Error **errp); int postcopy_preempt_wait_channel(MigrationState *s); diff --git a/migration/channel.c b/migration/channel.c index XXXXXXX..XXXXXXX 100644 --- a/migration/channel.c +++ b/migration/channel.c @@ -XXX,XX +XXX,XX @@ void migration_channel_connect(MigrationState *s, migrate_fd_connect(s, error); error_free(error); } + + +/** + * @migration_channel_read_peek - Peek at migration channel, without + * actually removing it from channel buffer. + * + * @ioc: the channel object + * @buf: the memory region to read data into + * @buflen: the number of bytes to read in @buf + * @errp: pointer to a NULL-initialized error object + * + * Returns 0 if successful, returns -1 and sets @errp if fails. + */ +int migration_channel_read_peek(QIOChannel *ioc, + const char *buf, + const size_t buflen, + Error **errp) +{ + ssize_t len = 0; + struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen }; + + while (true) { + len = qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, + QIO_CHANNEL_READ_FLAG_MSG_PEEK, errp); + + if (len <= 0 && len != QIO_CHANNEL_ERR_BLOCK) { + error_setg(errp, + "Failed to peek at channel"); + return -1; + } + + if (len == buflen) { + break; + } + + /* 1ms sleep. */ + if (qemu_in_coroutine()) { + qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 1000000); + } else { + g_usleep(1000); + } + } + + return 0; +} diff --git a/migration/migration.c b/migration/migration.c index XXXXXXX..XXXXXXX 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -XXX,XX +XXX,XX @@ #include "migration.h" #include "savevm.h" #include "qemu-file.h" +#include "channel.h" #include "migration/vmstate.h" #include "block/block.h" #include "qapi/error.h" @@ -XXX,XX +XXX,XX @@ static bool migration_incoming_setup(QEMUFile *f, Error **errp) { MigrationIncomingState *mis = migration_incoming_get_current(); - if (multifd_load_setup(errp) != 0) { - return false; - } - if (!mis->from_src_file) { mis->from_src_file = f; } @@ -XXX,XX +XXX,XX @@ void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp) { MigrationIncomingState *mis = migration_incoming_get_current(); Error *local_err = NULL; - bool start_migration; QEMUFile *f; + bool default_channel = true; + uint32_t channel_magic = 0; + int ret = 0; - if (!mis->from_src_file) { - /* The first connection (multifd may have multiple) */ + if (migrate_use_multifd() && !migrate_postcopy_ram() && + qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_READ_MSG_PEEK)) { + /* + * With multiple channels, it is possible that we receive channels + * out of order on destination side, causing incorrect mapping of + * source channels on destination side. Check channel MAGIC to + * decide type of channel. Please note this is best effort, postcopy + * preempt channel does not send any magic number so avoid it for + * postcopy live migration. Also tls live migration already does + * tls handshake while initializing main channel so with tls this + * issue is not possible. + */ + ret = migration_channel_read_peek(ioc, (void *)&channel_magic, + sizeof(channel_magic), &local_err); + + if (ret != 0) { + error_propagate(errp, local_err); + return; + } + + default_channel = (channel_magic == cpu_to_be32(QEMU_VM_FILE_MAGIC)); + } else { + default_channel = !mis->from_src_file; + } + + if (multifd_load_setup(errp) != 0) { + error_setg(errp, "Failed to setup multifd channels"); + return; + } + + if (default_channel) { f = qemu_file_new_input(ioc); if (!migration_incoming_setup(f, errp)) { return; } - - /* - * Common migration only needs one channel, so we can start - * right now. Some features need more than one channel, we wait. - */ - start_migration = !migration_needs_multiple_sockets(); } else { /* Multiple connections */ assert(migration_needs_multiple_sockets()); if (migrate_use_multifd()) { - start_migration = multifd_recv_new_channel(ioc, &local_err); + multifd_recv_new_channel(ioc, &local_err); } else { assert(migrate_postcopy_preempt()); f = qemu_file_new_input(ioc); - start_migration = postcopy_preempt_new_channel(mis, f); + postcopy_preempt_new_channel(mis, f); } if (local_err) { error_propagate(errp, local_err); @@ -XXX,XX +XXX,XX @@ void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp) } } - if (start_migration) { + if (migration_has_all_channels()) { /* If it's a recovery, we're done */ if (postcopy_try_recover()) { return; diff --git a/migration/multifd.c b/migration/multifd.c index XXXXXXX..XXXXXXX 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -XXX,XX +XXX,XX @@ int multifd_load_setup(Error **errp) uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); uint8_t i; - if (!migrate_use_multifd()) { + /* + * Return successfully if multiFD recv state is already initialised + * or multiFD is not enabled. + */ + if (multifd_recv_state || !migrate_use_multifd()) { return 0; } + if (!migrate_multi_channels_is_allowed()) { error_setg(errp, "multifd is not supported by current protocol"); return -1; @@ -XXX,XX +XXX,XX @@ bool multifd_recv_all_channels_created(void) /* * Try to receive all multifd channels to get ready for the migration. - * - Return true and do not set @errp when correctly receiving all channels; - * - Return false and do not set @errp when correctly receiving the current one; - * - Return false and set @errp when failing to receive the current channel. + * Sets @errp when failing to receive the current channel. */ -bool multifd_recv_new_channel(QIOChannel *ioc, Error **errp) +void multifd_recv_new_channel(QIOChannel *ioc, Error **errp) { MultiFDRecvParams *p; Error *local_err = NULL; @@ -XXX,XX +XXX,XX @@ bool multifd_recv_new_channel(QIOChannel *ioc, Error **errp) "failed to receive packet" " via multifd channel %d: ", qatomic_read(&multifd_recv_state->count)); - return false; + return; } trace_multifd_recv_new_channel(id); @@ -XXX,XX +XXX,XX @@ bool multifd_recv_new_channel(QIOChannel *ioc, Error **errp) id); multifd_recv_terminate_threads(local_err); error_propagate(errp, local_err); - return false; + return; } p->c = ioc; object_ref(OBJECT(ioc)); @@ -XXX,XX +XXX,XX @@ bool multifd_recv_new_channel(QIOChannel *ioc, Error **errp) qemu_thread_create(&p->thread, p->name, multifd_recv_thread, p, QEMU_THREAD_JOINABLE); qatomic_inc(&multifd_recv_state->count); - return qatomic_read(&multifd_recv_state->count) == - migrate_multifd_channels(); } diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -XXX,XX +XXX,XX @@ void postcopy_unregister_shared_ufd(struct PostCopyFD *pcfd) } } -bool postcopy_preempt_new_channel(MigrationIncomingState *mis, QEMUFile *file) +void postcopy_preempt_new_channel(MigrationIncomingState *mis, QEMUFile *file) { /* * The new loading channel has its own threads, so it needs to be @@ -XXX,XX +XXX,XX @@ bool postcopy_preempt_new_channel(MigrationIncomingState *mis, QEMUFile *file) qemu_file_set_blocking(file, true); mis->postcopy_qemufile_dst = file; trace_postcopy_preempt_new_channel(); - - /* Start the migration immediately */ - return true; } /* -- 2.39.1 The following changes since commit 30e8a06b64aa58a3990ba39cb5d09531e7d265e0: Merge tag 'net-pull-request' of https://github.com/jasowang/qemu into staging (2026-06-29 17:41:42 +0200) are available in the Git repository at: https://gitlab.com/peterx/qemu.git tags/next-pull-request for you to fetch changes up to 60f2281450c4b4e9a16922fd69c66486a8207abb: migration: clean up postcopy blocktime presentation (2026-07-17 12:33:42 -0400) ---------------------------------------------------------------- Migration pull for rc1 - Bin's cleanup on migration blocktime (partly) - Yujun's fix on print format ---------------------------------------------------------------- Bin Guo (2): migration: fix ineffective overflow assert in postcopy blocktime migration: clean up postcopy blocktime presentation yujun (1): migration: Fix invalid %ud format and trace arg typo migration/migration-hmp-cmds.c | 2 +- migration/postcopy-ram.c | 14 ++++++-------- migration/trace-events | 6 +++--- 3 files changed, 10 insertions(+), 12 deletions(-) -- 2.54.0 From: yujun <yujun@kylinos.cn> Standard printf has no %ud conversion; glibc treats it as %u followed by a literal 'd', so postcopy userfaultfd error messages printed event values like "5d" instead of "5". The same typo existed in two postcopy discard trace format strings. Also rename the misspelled ram_save_iterate_big_wait() trace argument milliconds to milliseconds. Fixes: 00fa4fc85b ("postcopy: Allow registering of fd handler") Signed-off-by: yujun <yujun@kylinos.cn> Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20260630031324.43453-1-yujun@kylinos.cn Signed-off-by: Peter Xu <peterx@redhat.com> --- migration/postcopy-ram.c | 4 ++-- migration/trace-events | 6 +++--- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -XXX,XX +XXX,XX @@ static void *postcopy_ram_fault_thread(void *opaque) } } if (msg.event != UFFD_EVENT_PAGEFAULT) { - error_report("%s: Read unexpected event %ud from userfaultfd", + error_report("%s: Read unexpected event %u from userfaultfd", __func__, msg.event); continue; /* It's not a page fault, shouldn't happen */ } @@ -XXX,XX +XXX,XX @@ retry: } } if (msg.event != UFFD_EVENT_PAGEFAULT) { - error_report("%s: Read unexpected event %ud " + error_report("%s: Read unexpected event %u " "from userfaultfd (shared)", __func__, msg.event); continue; /* It's not a page fault, shouldn't happen */ diff --git a/migration/trace-events b/migration/trace-events index XXXXXXX..XXXXXXX 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -XXX,XX +XXX,XX @@ loadvm_postcopy_handle_run(void) "" loadvm_postcopy_handle_resume(void) "" loadvm_postcopy_ram_handle_discard(void) "" loadvm_postcopy_ram_handle_discard_end(void) "" -loadvm_postcopy_ram_handle_discard_header(const char *ramid, uint16_t len) "%s: %ud" +loadvm_postcopy_ram_handle_discard_header(const char *ramid, uint16_t len) "%s: %u" loadvm_process_command(const char *s, uint16_t len) "com=%s len=%d" loadvm_process_command_ping(uint32_t val) "0x%x" loadvm_approve_switchover(unsigned int switchover_ack_pending_num) "Switchover ack pending num=%u" postcopy_ram_listen_thread_exit(void) "" postcopy_ram_listen_thread_start(void) "" qemu_savevm_send_postcopy_advise(void) "" -qemu_savevm_send_postcopy_ram_discard(const char *id, uint16_t len) "%s: %ud" +qemu_savevm_send_postcopy_ram_discard(const char *id, uint16_t len) "%s: %u" savevm_command_send(uint16_t command, uint16_t len) "com=0x%x len=%d" savevm_section_start(const char *id, unsigned int section_id) "%s, section_id %u" savevm_section_end(const char *id, unsigned int section_id, int ret) "%s, section_id %u -> %d" @@ -XXX,XX +XXX,XX @@ colo_flush_ram_cache_begin(uint64_t dirty_pages) "dirty_pages %" PRIu64 colo_flush_ram_cache_end(void) "" save_xbzrle_page_skipping(void) "" save_xbzrle_page_overflow(void) "" -ram_save_iterate_big_wait(uint64_t milliconds, int iterations) "big wait: %" PRIu64 " milliseconds, %d iterations" +ram_save_iterate_big_wait(uint64_t milliseconds, int iterations) "big wait: %" PRIu64 " milliseconds, %d iterations" ram_load_start(void) "" ram_load_complete(int ret, uint64_t seq_iter) "exit_code %d seq iteration %" PRIu64 ram_write_tracking_ramblock_start(const char *block_id, size_t page_size, void *addr, size_t length) "%s: page_size: %zu addr: %p length: %zu" -- 2.54.0 From: Bin Guo <guobin@linux.alibaba.com> vcpu_faults_current[] is uint8_t. The overflow assert was checked after the post-increment, so 255 would wrap to 0 and the assert would pass silently. Move the check before the increment and use < 255. Signed-off-by: Bin Guo <guobin@linux.alibaba.com> Link: https://lore.kernel.org/r/20260716101952.65329-2-guobin@linux.alibaba.com Signed-off-by: Peter Xu <peterx@redhat.com> --- migration/postcopy-ram.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -XXX,XX +XXX,XX @@ void mark_postcopy_blocktime_begin(uintptr_t addr, uint32_t ptid, /* * Account how many concurrent faults on this vCPU we trapped. See * comments above vcpu_faults_current[] on why it can be more than one. + * + * vcpu_faults_current[] is uint8_t, so assert before incrementing to + * catch overflow before it wraps. */ + assert(dc->vcpu_faults_current[cpu] < 255); if (dc->vcpu_faults_current[cpu]++ == 0) { dc->smp_cpus_down++; /* @@ -XXX,XX +XXX,XX @@ void mark_postcopy_blocktime_begin(uintptr_t addr, uint32_t ptid, */ dc->last_begin = current; } - - /* Making sure it won't overflow - it really should never! */ - assert(dc->vcpu_faults_current[cpu] <= 255); } else { /* * For non-vCPU thread faults, we don't care about tid or cpu index -- 2.54.0 From: Bin Guo <guobin@linux.alibaba.com> Small cleanups for the postcopy blocktime fine-grained tracking feature: * Remove a redundant memset() on latency_buckets after g_new0(). * Use singular "Latency" in the HMP label for postcopy non-vCPU latency, consistent with other single-value labels. Signed-off-by: Bin Guo <guobin@linux.alibaba.com> Link: https://lore.kernel.org/r/20260716101952.65329-4-guobin@linux.alibaba.com Signed-off-by: Peter Xu <peterx@redhat.com> --- migration/migration-hmp-cmds.c | 2 +- migration/postcopy-ram.c | 3 --- 2 files changed, 1 insertion(+), 4 deletions(-) diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c index XXXXXXX..XXXXXXX 100644 --- a/migration/migration-hmp-cmds.c +++ b/migration/migration-hmp-cmds.c @@ -XXX,XX +XXX,XX @@ static void migration_dump_blocktime(Monitor *mon, MigrationInfo *info) } if (info->has_postcopy_non_vcpu_latency) { - monitor_printf(mon, "Postcopy non-vCPU Latencies (ns): %" PRIu64 "\n", + monitor_printf(mon, "Postcopy non-vCPU Latency (ns): %" PRIu64 "\n", info->postcopy_non_vcpu_latency); } diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index XXXXXXX..XXXXXXX 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -XXX,XX +XXX,XX @@ static struct PostcopyBlocktimeContext *blocktime_context_new(void) unsigned int smp_cpus = ms->smp.cpus; PostcopyBlocktimeContext *ctx = g_new0(PostcopyBlocktimeContext, 1); - /* Initialize all counters to be zeros */ - memset(ctx->latency_buckets, 0, sizeof(ctx->latency_buckets)); - ctx->vcpu_blocktime_total = g_new0(uint64_t, smp_cpus); ctx->vcpu_faults_count = g_new0(uint64_t, smp_cpus); ctx->vcpu_faults_current = g_new0(uint8_t, smp_cpus); -- 2.54.0