[PATCH 20/78] virtio: make virtio_delete_queue idempotent

[Michael Roth]

From: "Michael S. Tsirkin" <mst@redhat.com>

Let's make sure calling this twice is harmless -
no known instances, but seems safer.

Suggested-by: Pan Nengyuan <pannengyuan@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 8cd353ea0fbf0e334e015d833f612799be642296)
*prereq for 421afd2fe8
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/virtio/virtio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 31dd140990..6de3cfdc2c 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2337,6 +2337,7 @@ void virtio_delete_queue(VirtQueue *vq)
     vq->handle_output = NULL;
     vq->handle_aio_output = NULL;
     g_free(vq->used_elems);
+    vq->used_elems = NULL;
 }
 
 void virtio_del_queue(VirtIODevice *vdev, int n)
-- 
2.17.1