On 06/05/2024 17:39, Cédric Le Goater wrote:
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Hello Avihai,
On 4/30/24 07:16, Avihai Horon wrote:
When migrating a VFIO device that supports pre-copy, it is transitioned
to STOP_COPY twice: once in vfio_vmstate_change() and second time in
vfio_save_complete_precopy().
The second transition is harmless, as it's a STOP_COPY->STOP_COPY no-op
transition. However, with the newly added migration state change QAPI
event, the STOP_COPY state change event is undesirably emitted twice.
Prevent this by conditionally transitioning to STOP_COPY state in
vfio_save_complete_precopy().
Note that the STOP_COPY transition in vfio_save_complete_precopy() is
essential for VFIO devices that don't support pre-copy, for migrating an
already stopped guest and for snapshots.
Signed-off-by: Avihai Horon <avih...@nvidia.com>
---
hw/vfio/migration.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index 6bbccf6545..30a2b2ea74 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -591,14 +591,17 @@ static int vfio_save_iterate(QEMUFile *f, void
*opaque)
static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
{
VFIODevice *vbasedev = opaque;
+ VFIOMigration *migration = vbasedev->migration;
ssize_t data_size;
int ret;
/* We reach here with device state STOP or STOP_COPY only */
- ret = vfio_migration_set_state(vbasedev,
VFIO_DEVICE_STATE_STOP_COPY,
- VFIO_DEVICE_STATE_STOP);
- if (ret) {
- return ret;
+ if (migration->device_state == VFIO_DEVICE_STATE_STOP) {
Shouldn't we handle no-op transitions in vfio_migration_set_state()
instead ?
Yes, you are right. It's better to handle the general case in
vfio_migration_set_state().
Will change it.
Thanks.
Thanks,
C.
+ ret = vfio_migration_set_state(vbasedev,
VFIO_DEVICE_STATE_STOP_COPY,
+ VFIO_DEVICE_STATE_STOP);
+ if (ret) {
+ return ret;
+ }
}
do {
