diff options
Diffstat (limited to 'virtio.c')
| -rw-r--r-- | virtio.c | 15 |
1 files changed, 15 insertions, 0 deletions
@@ -284,6 +284,9 @@ static int virtqueue_read_next_desc(const struct vring_desc *desc, */ bool vu_queue_empty(struct vu_virtq *vq) { + if (!vq->vring.avail) + return true; + if (vq->shadow_avail_idx != vq->last_avail_idx) return false; @@ -327,6 +330,9 @@ static bool vring_can_notify(const struct vu_dev *dev, struct vu_virtq *vq) */ void vu_queue_notify(const struct vu_dev *dev, struct vu_virtq *vq) { + if (!vq->vring.avail) + return; + if (!vring_can_notify(dev, vq)) { debug("vhost-user: virtqueue can skip notify..."); return; @@ -502,6 +508,9 @@ int vu_queue_pop(struct vu_dev *dev, struct vu_virtq *vq, struct vu_virtq_elemen unsigned int head; int ret; + if (!vq->vring.avail) + return -1; + if (vu_queue_empty(vq)) return -1; @@ -591,6 +600,9 @@ void vu_queue_fill_by_index(struct vu_virtq *vq, unsigned int index, { struct vring_used_elem uelem; + if (!vq->vring.avail) + return; + idx = (idx + vq->used_idx) % vq->vring.num; uelem.id = htole32(index); @@ -633,6 +645,9 @@ void vu_queue_flush(struct vu_virtq *vq, unsigned int count) { uint16_t old, new; + if (!vq->vring.avail) + return; + /* Make sure buffer is written before we update index. */ smp_wmb(); |