We should use vq->last_avail_idx instead of vq->avail_idx in the checking of vhost_vq_avail_empty() since latter is the cached avail index from guest but we want to know if there's pending available buffers in the virtqueue.
Signed-off-by: Jason Wang <jasow...@redhat.com> --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c6f2d89..fdf4cdf 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -2230,7 +2230,7 @@ bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) if (r) return false; - return vhost16_to_cpu(vq, avail_idx) == vq->avail_idx; + return vhost16_to_cpu(vq, avail_idx) == vq->last_avail_idx; } EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); -- 2.7.4