[PATCH] migration: failover: emit a warning when the card is not fully unplugged

[Laurent Vivier <lvivier@redhat.com>]

When the migration fails or is canceled we wait the end of the unplug
operation to be able to plug it back. But if the unplug operation
is never finished we stop to wait and QEMU emits a warning to inform
the user.

Based-on: 20210629155007.629086-1-lvivier@redhat.com
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 migration/migration.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/migration/migration.c b/migration/migration.c
index 3b06d43a7f42..e065c62e5189 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -3689,6 +3689,10 @@ static void qemu_savevm_wait_unplug(MigrationState *s, int old_state,
             while (timeout-- && qemu_savevm_state_guest_unplug_pending()) {
                 qemu_sem_timedwait(&s->wait_unplug_sem, 250);
             }
+            if (qemu_savevm_state_guest_unplug_pending()) {
+                warn_report("migration: partially unplugged device on "
+                            "failure");
+            }
         }
 
         migrate_set_state(&s->state, MIGRATION_STATUS_WAIT_UNPLUG, new_state);
-- 
2.31.1