On 09/18/2015 02:01 AM, Jason Wang wrote:
> Factor out sg unmapping logic. This will be reused by the patch that
> can discard descriptor.
>
> Cc: Michael S. Tsirkin <[email protected]>
> Signed-off-by: Jason Wang <[email protected]>
> ---
> hw/virtio/virtio.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 0832db9..eb8d5ca 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -243,15 +243,12 @@ 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);
>
Should the "offset = 0" really be dropped here? Seems like it ends
up uninitialized. GCC thinks it might too.
> @@ -266,6 +263,14 @@ 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;
>
>
Thanks,
--
Andrew James
