virtio: introduce virtqueue_discard()

This patch introduces virtqueue_discard() to discard a descriptor and
unmap the sgs. This will be used by the patch that will discard
descriptor when packet is truncated.

Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Jason Wang 2015-09-25 13:21:29 +08:00 committed by Michael S. Tsirkin
parent ce31746157
commit 29b9f5efd7
2 changed files with 9 additions and 0 deletions
hw/virtio
include/hw/virtio

View File

@ -267,6 +267,13 @@ static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem,
0, elem->out_sg[i].iov_len); 0, elem->out_sg[i].iov_len);
} }
void virtqueue_discard(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len)
{
vq->last_avail_idx--;
virtqueue_unmap_sg(vq, elem, len);
}
void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len, unsigned int idx) unsigned int len, unsigned int idx)
{ {

View File

@ -146,6 +146,8 @@ void virtio_del_queue(VirtIODevice *vdev, int n);
void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len); unsigned int len);
void virtqueue_flush(VirtQueue *vq, unsigned int count); void virtqueue_flush(VirtQueue *vq, unsigned int count);
void virtqueue_discard(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len);
void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
unsigned int len, unsigned int idx); unsigned int len, unsigned int idx);