aboutsummaryrefslogtreecommitdiff
path: root/drivers/virtio/virtio_ring.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/virtio/virtio_ring.c')
-rw-r--r--drivers/virtio/virtio_ring.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index a882f260651..fbd2ecde93e 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -208,7 +208,11 @@ add_head:
pr_debug("Added buffer head %i to %p\n", head, vq);
END_USE(vq);
- return 0;
+
+ /* If we're indirect, we can fit many (assuming not OOM). */
+ if (vq->indirect)
+ return vq->num_free ? vq->vring.num : 0;
+ return vq->num_free;
}
static void vring_kick(struct virtqueue *_vq)
@@ -281,6 +285,9 @@ static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len)
return NULL;
}
+ /* Only get used array entries after they have been exposed by host. */
+ rmb();
+
i = vq->vring.used->ring[vq->last_used_idx%vq->vring.num].id;
*len = vq->vring.used->ring[vq->last_used_idx%vq->vring.num].len;