diff mbox series

[PULL,2/3] vfio/migration: Skip log_sync during migration SETUP state

Message ID 20230509215923.3186420-3-alex.williamson@redhat.com (mailing list archive)
State New, archived
Headers show
Series [PULL,1/3] vfio/pci: add support for VF token | expand

Commit Message

Alex Williamson May 9, 2023, 9:59 p.m. UTC 
From: Avihai Horon <avihaih@nvidia.com>

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 <avihaih@nvidia.com>
Link: https://lore.kernel.org/r/20230403130000.6422-1-avihaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/vfio/common.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 4d01ea351515..78358ede2764 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;
     }