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>
---
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;
}
--
2.21.3
