Commit ce317461 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

virtio: introduce virtqueue_unmap_sg() 



Factor out sg unmapping logic. This will be reused by the patch that
can discard descriptor.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Andrew James <andrew.james@hpe.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent fa500928

hw/virtio/virtio.c

+10 −4
Original line number Diff line number Diff line
@@ -244,14 +244,12 @@ int virtio_queue_empty(VirtQueue *vq) 
    return vring_avail_idx(vq) == vq->last_avail_idx;

}



void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,

                    unsigned int len, unsigned int idx)

static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem,

                               unsigned int len)

{

    unsigned int offset;

    int i;



    trace_virtqueue_fill(vq, elem, len, idx);



    offset = 0;

    for (i = 0; i < elem->in_num; i++) {

        size_t size = MIN(len - offset, elem->in_sg[i].iov_len);
@@ -267,6 +265,14 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 
        cpu_physical_memory_unmap(elem->out_sg[i].iov_base,

                                  elem->out_sg[i].iov_len,

                                  0, elem->out_sg[i].iov_len);

}



void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,

                    unsigned int len, unsigned int idx)

{

    trace_virtqueue_fill(vq, elem, len, idx);



    virtqueue_unmap_sg(vq, elem, len);



    idx = (idx + vring_used_idx(vq)) % vq->vring.num;