virtio_ring: let virtqueue_{kick()/notify()} return a bool
virtqueue_{kick()/notify()} should exploit the new host notification API.
If the notify call returned with a negative value the host kick failed
(e.g. a kick triggered after a device was hot-unplugged). In this case
the virtqueue is set to 'broken' and false is returned, otherwise true.
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 97dd516..b471427 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -430,13 +430,22 @@
* @vq: the struct virtqueue
*
* This does not need to be serialized.
+ *
+ * Returns false if host notify failed or queue is broken, otherwise true.
*/
-void virtqueue_notify(struct virtqueue *_vq)
+bool virtqueue_notify(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
+ if (unlikely(vq->broken))
+ return false;
+
/* Prod other side to tell it about changes. */
- vq->notify(_vq);
+ if (vq->notify(_vq) < 0) {
+ vq->broken = true;
+ return false;
+ }
+ return true;
}
EXPORT_SYMBOL_GPL(virtqueue_notify);
@@ -449,11 +458,14 @@
*
* Caller must ensure we don't call this with other virtqueue
* operations at the same time (except where noted).
+ *
+ * Returns false if kick failed, otherwise true.
*/
-void virtqueue_kick(struct virtqueue *vq)
+bool virtqueue_kick(struct virtqueue *vq)
{
if (virtqueue_kick_prepare(vq))
- virtqueue_notify(vq);
+ return virtqueue_notify(vq);
+ return true;
}
EXPORT_SYMBOL_GPL(virtqueue_kick);