Commit b13919ab authored by Marc-André Lureau's avatar Marc-André Lureau Committed by Michael S. Tsirkin
Browse files

libvhost-user: add vu_queue_unpop() 



vhost-user-input will make use of this function to undo some queue pop
in case the virtio queue does not have enough room.

Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190308140454.32437-11-marcandre.lureau@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 922ef483

contrib/libvhost-user/libvhost-user.c

+16 −0
Original line number Diff line number Diff line
@@ -1966,6 +1966,22 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz) 
    return elem;

}



static void

vu_queue_detach_element(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem,

                        size_t len)

{

    vq->inuse--;

    /* unmap, when DMA support is added */

}



void

vu_queue_unpop(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem,

               size_t len)

{

    vq->last_avail_idx--;

    vu_queue_detach_element(dev, vq, elem, len);

}



bool

vu_queue_rewind(VuDev *dev, VuVirtq *vq, unsigned int num)

{

contrib/libvhost-user/libvhost-user.h

+14 −0
Original line number Diff line number Diff line
@@ -458,6 +458,20 @@ void vu_queue_notify(VuDev *dev, VuVirtq *vq); 
 */

void *vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz);





/**

 * vu_queue_unpop:

 * @dev: a VuDev context

 * @vq: a VuVirtq queue

 * @elem: The #VuVirtqElement

 * @len: number of bytes written

 *

 * Pretend the most recent element wasn't popped from the virtqueue.  The next

 * call to vu_queue_pop() will refetch the element.

 */

void vu_queue_unpop(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem,

                    size_t len);



/**

 * vu_queue_rewind:

 * @dev: a VuDev context