Re: [PATCH v2] virtio_ring: use shadow flags when detaching split descriptors

[Xuan Zhuo]

On Tue,  6 Oct 2026 19:21:12 +0900, sungbyeongchan <tjdqudcks0424@xxxxxxxxx> wrote:
> Fixes: 72b5e8958738 ("virtio-ring: store DMA metadata in desc_extra for split virtqueue")
> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> Assisted-by: LLM
> Signed-off-by: sungbyeongchan <tjdqudcks0424@xxxxxxxxx>
> ---
> Changes in v2:
> - Drop the commit message paragraphs as requested by Michael S. Tsirkin.

You misunderstood him.

We can not accept a commit without commit message.


> - Add Michael's Acked-by.
>
>  drivers/virtio/virtio_ring.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index db678f5a80e03..b4cb433df1dec 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -905,7 +905,6 @@ static unsigned detach_buf_split_in_order(struct vring_virtqueue *vq,
>  {
>  	struct vring_desc_extra *extra;
>  	unsigned int i;
> -	__virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT);
>
>  	/* Clear data ptr. */
>  	vq->split.desc_state[head].data = NULL;
> @@ -915,7 +914,7 @@ static unsigned detach_buf_split_in_order(struct vring_virtqueue *vq,
>  	/* Put back on free list: unmap first-level descriptors and find end */
>  	i = head;
>
> -	while (vq->split.vring.desc[i].flags & nextflag) {
> +	while (extra[i].flags & VRING_DESC_F_NEXT) {
>  		i = vring_unmap_one_split(vq, &extra[i]);
>  		vq->vq.num_free++;
>  	}
> --
> 2.43.0
>