Re: [PATCH] virtio-ring: fix DMA metadata flags

[Jason Wang]

On Tue, Oct 26, 2021 at 9:31 PM Vincent Whitchurch
<vincent.whitchurch@xxxxxxxx> wrote:
>
> The flags are currently overwritten, leading to the wrong direction
> being passed to the DMA unmap functions.
>
> Fixes: 72b5e8958738aaa4 ("virtio-ring: store DMA metadata in desc_extra for split virtqueue")
> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>

Acked-by: Jason Wang <jasowang@xxxxxxxxxx>

Thanks

> ---
>  drivers/virtio/virtio_ring.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index dd95dfd85e98..3035bb6f5458 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -576,7 +576,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>         /* Last one doesn't continue. */
>         desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT);
>         if (!indirect && vq->use_dma_api)
> -               vq->split.desc_extra[prev & (vq->split.vring.num - 1)].flags =
> +               vq->split.desc_extra[prev & (vq->split.vring.num - 1)].flags &=
>                         ~VRING_DESC_F_NEXT;
>
>         if (indirect) {
> --
> 2.28.0
>