[PATCH v3 14/17] vfio/migration: Reset device if setting recover state fails

[Avihai Horon]

If vfio_migration_set_state() fails to set the device in the requested
state it tries to put it in a recover state. If setting the device in
the recover state fails as well, hw_error is triggered and the VM is
aborted.

To improve user experience and avoid VM data loss, reset the device with
VFIO_RESET_DEVICE instead of aborting the VM.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
---
 hw/vfio/migration.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index f8c3228314..e8068b9147 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -92,8 +92,18 @@ static int vfio_migration_set_state(VFIODevice *vbasedev,
 
         mig_state->device_state = recover_state;
         if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) {
-            hw_error("%s: Failed setting device in recover state, err: %s",
-                     vbasedev->name, strerror(errno));
+            error_report(
+                "%s: Failed setting device in recover state, err: %s. 
Resetting device",
+                         vbasedev->name, strerror(errno));
+
+            if (ioctl(vbasedev->fd, VFIO_DEVICE_RESET)) {
+                hw_error("%s: Failed resetting device, err: %s", 
vbasedev->name,
+                         strerror(errno));
+            }
+
+            migration->device_state = VFIO_DEVICE_STATE_RUNNING;
+
+            return -1;
         }
 
         migration->device_state = recover_state;
-- 
2.21.3