[PATCH v3 1/3] virtio: add ability to delete vq through a pointer

[pannengyuan]

From: Michael S. Tsirkin <address@hidden> 

Devices tend to maintain vq pointers, allow deleting them through a vq
pointer.

Signed-off-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Pan Nengyuan <address@hidden>
[PMM: change function name to virtio_queue_cleanup; set used_elems to NULL 
after free]
Cc: Amit Shah <address@hidden>
Reviewed-by: Pankaj Gupta <address@hidden>
Reviewed-by: Laurent Vivier <address@hidden>
---
Changes v2 to v1:
- use virtio_delete_queue to cleanup vq through a vq pointer
---
Changes v3 to v2:
- change function name from virtio_delete_queue to virtio_queue_cleanup
---
 hw/virtio/virtio.c         | 16 +++++++++++-----
 include/hw/virtio/virtio.h |  2 ++
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 04716b5..2743258 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2330,17 +2330,23 @@ VirtQueue *virtio_add_queue(VirtIODevice *vdev, int 
queue_size,
     return &vdev->vq[i];
 }
 
+void virtio_queue_cleanup(VirtQueue *vq)
+{
+    vq->vring.num = 0;
+    vq->vring.num_default = 0;
+    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)
 {
     if (n < 0 || n >= VIRTIO_QUEUE_MAX) {
         abort();
     }
 
-    vdev->vq[n].vring.num = 0;
-    vdev->vq[n].vring.num_default = 0;
-    vdev->vq[n].handle_output = NULL;
-    vdev->vq[n].handle_aio_output = NULL;
-    g_free(vdev->vq[n].used_elems);
+    virtio_queue_cleanup(&vdev->vq[n]);
 }
 
 static void virtio_set_isr(VirtIODevice *vdev, int value)
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index c32a815..cc0b3f0 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -183,6 +183,8 @@ VirtQueue *virtio_add_queue(VirtIODevice *vdev, int 
queue_size,
 
 void virtio_del_queue(VirtIODevice *vdev, int n);
 
+void virtio_queue_cleanup(VirtQueue *vq);
+
 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
                     unsigned int len);
 void virtqueue_flush(VirtQueue *vq, unsigned int count);
-- 
2.7.2.windows.1