On 4/3/23 15:00, Avihai Horon wrote:
Currently, VFIO log_sync can be issued while migration is in SETUP state. However, doing this log_sync is at best redundant and at worst can fail.Redundant -- all RAM is marked dirty in migration SETUP state and is transferred only after migration is set to ACTIVE state, so doing log_sync during migration SETUP is pointless. Can fail -- there is a time window, between setting migration state to SETUP and starting dirty tracking by RAM save_live_setup handler, during which dirty tracking is still not started. Any VFIO log_sync call that is issued during this time window will fail. For example, this error can be triggered by migrating a VM when a GUI is active, which constantly calls log_sync. Fix it by skipping VFIO log_sync while migration is in SETUP state. Fixes: 758b96b61d5c ("vfio/migrate: Move switch of dirty tracking into vfio_memory_listener") Signed-off-by: Avihai Horon <avih...@nvidia.com>
migration is still experimental, so this can wait 8.1. Correct me if not. Thanks, C.
--- hw/vfio/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 4d01ea3515..78358ede27 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -478,7 +478,8 @@ static bool vfio_devices_all_dirty_tracking(VFIOContainer *container) VFIODevice *vbasedev; MigrationState *ms = migrate_get_current();- if (!migration_is_setup_or_active(ms->state)) {+ if (ms->state != MIGRATION_STATUS_ACTIVE && + ms->state != MIGRATION_STATUS_DEVICE) { return false; }
