diff options
Diffstat (limited to 'drivers/vhost/vhost.c')
| -rw-r--r-- | drivers/vhost/vhost.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 65a1d2da114a..73d4545ee0d3 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1661,6 +1661,20 @@ void vhost_add_used_and_signal_n(struct vhost_dev *dev, } EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n); +/* return true if we're sure that avaiable ring is empty */ +bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) +{ + __virtio16 avail_idx; + int r; + + r = __get_user(avail_idx, &vq->avail->idx); + if (r) + return false; + + return vhost16_to_cpu(vq, avail_idx) == vq->avail_idx; +} +EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); + /* OK, now we need to know about added descriptors. */ bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) { |