Re: [PATCH V6 06/19] virtio_ring: switch to use vring_virtqueue for virtqueue_add variants

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Sep 19, 2025 at 03:31:41PM +0800, Jason Wang wrote:
> Those variants are used internally so let's switch to use
> vring_virtqueue as parameter to be consistent with other internal
> virtqueue helpers.
> 
> Acked-by: Eugenio Pérez <eperezma@redhat.com>
> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/virtio/virtio_ring.c | 40 +++++++++++++++++-------------------
>  1 file changed, 19 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index aadeab66e57c..93c36314b5e7 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -476,7 +476,7 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq,
>  	return extra->next;
>  }
>  
> -static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq,
> +static struct vring_desc *alloc_indirect_split(struct vring_virtqueue *vq,
>  					       unsigned int total_sg,
>  					       gfp_t gfp)
>  {
> @@ -505,7 +505,7 @@ static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq,
>  	return desc;
>  }
>  
> -static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq,
> +static inline unsigned int virtqueue_add_desc_split(struct vring_virtqueue *vq,
>  						    struct vring_desc *desc,
>  						    struct vring_desc_extra *extra,
>  						    unsigned int i,
> @@ -513,11 +513,12 @@ static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq,
>  						    unsigned int len,
>  						    u16 flags, bool premapped)
>  {
> +	struct virtio_device *vdev = vq->vq.vdev;
>  	u16 next;
>  
> -	desc[i].flags = cpu_to_virtio16(vq->vdev, flags);
> -	desc[i].addr = cpu_to_virtio64(vq->vdev, addr);
> -	desc[i].len = cpu_to_virtio32(vq->vdev, len);
> +	desc[i].flags = cpu_to_virtio16(vdev, flags);
> +	desc[i].addr = cpu_to_virtio64(vdev, addr);
> +	desc[i].len = cpu_to_virtio32(vdev, len);
>  
>  	extra[i].addr = premapped ? DMA_MAPPING_ERROR : addr;
>  	extra[i].len = len;
> @@ -525,12 +526,12 @@ static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq,
>  
>  	next = extra[i].next;
>  
> -	desc[i].next = cpu_to_virtio16(vq->vdev, next);
> +	desc[i].next = cpu_to_virtio16(vdev, next);
>  
>  	return next;
>  }
>  
> -static inline int virtqueue_add_split(struct virtqueue *_vq,
> +static inline int virtqueue_add_split(struct vring_virtqueue *vq,
>  				      struct scatterlist *sgs[],
>  				      unsigned int total_sg,
>  				      unsigned int out_sgs,
> @@ -540,7 +541,6 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>  				      bool premapped,
>  				      gfp_t gfp)
>  {
> -	struct vring_virtqueue *vq = to_vvq(_vq);
>  	struct vring_desc_extra *extra;
>  	struct scatterlist *sg;
>  	struct vring_desc *desc;
> @@ -565,7 +565,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>  	head = vq->free_head;
>  
>  	if (virtqueue_use_indirect(vq, total_sg))
> -		desc = alloc_indirect_split(_vq, total_sg, gfp);
> +		desc = alloc_indirect_split(vq, total_sg, gfp);
>  	else {
>  		desc = NULL;
>  		WARN_ON_ONCE(total_sg > vq->split.vring.num && !vq->indirect);
> @@ -612,7 +612,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>  			/* Note that we trust indirect descriptor
>  			 * table since it use stream DMA mapping.
>  			 */
> -			i = virtqueue_add_desc_split(_vq, desc, extra, i, addr, len,
> +			i = virtqueue_add_desc_split(vq, desc, extra, i, addr, len,
>  						     VRING_DESC_F_NEXT,
>  						     premapped);
>  		}
> @@ -629,14 +629,14 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>  			/* Note that we trust indirect descriptor
>  			 * table since it use stream DMA mapping.
>  			 */
> -			i = virtqueue_add_desc_split(_vq, desc, extra, i, addr, len,
> +			i = virtqueue_add_desc_split(vq, desc, extra, i, addr, len,
>  						     VRING_DESC_F_NEXT |
>  						     VRING_DESC_F_WRITE,
>  						     premapped);
>  		}
>  	}
>  	/* Last one doesn't continue. */
> -	desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT);
> +	desc[prev].flags &= cpu_to_virtio16(vq->vq.vdev, ~VRING_DESC_F_NEXT);
>  	if (!indirect && vring_need_unmap_buffer(vq, &extra[prev]))
>  		vq->split.desc_extra[prev & (vq->split.vring.num - 1)].flags &=
>  			~VRING_DESC_F_NEXT;
> @@ -649,7 +649,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>  		if (vring_mapping_error(vq, addr))
>  			goto unmap_release;
>  
> -		virtqueue_add_desc_split(_vq, vq->split.vring.desc,
> +		virtqueue_add_desc_split(vq, vq->split.vring.desc,
>  					 vq->split.desc_extra,
>  					 head, addr,
>  					 total_sg * sizeof(struct vring_desc),
> @@ -675,13 +675,13 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>  	/* Put entry in available array (but don't update avail->idx until they
>  	 * do sync). */
>  	avail = vq->split.avail_idx_shadow & (vq->split.vring.num - 1);
> -	vq->split.vring.avail->ring[avail] = cpu_to_virtio16(_vq->vdev, head);
> +	vq->split.vring.avail->ring[avail] = cpu_to_virtio16(vq->vq.vdev, head);
>  
>  	/* Descriptors and available array need to be set before we expose the
>  	 * new available array entries. */
>  	virtio_wmb(vq->weak_barriers);
>  	vq->split.avail_idx_shadow++;
> -	vq->split.vring.avail->idx = cpu_to_virtio16(_vq->vdev,
> +	vq->split.vring.avail->idx = cpu_to_virtio16(vq->vq.vdev,
>  						vq->split.avail_idx_shadow);
>  	vq->num_added++;
>  
> @@ -691,7 +691,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>  	/* This is very unlikely, but theoretically possible.  Kick
>  	 * just in case. */
>  	if (unlikely(vq->num_added == (1 << 16) - 1))
> -		virtqueue_kick(_vq);
> +		virtqueue_kick(&vq->vq);
>  
>  	return 0;
>  
> @@ -706,7 +706,6 @@ static inline int virtqueue_add_split(struct virtqueue *_vq,
>  	for (n = 0; n < total_sg; n++) {
>  		if (i == err_idx)
>  			break;
> -
>  		i = vring_unmap_one_split(vq, &extra[i]);
>  	}
>

can't say I like this, error handling is better separated visually from
good path.
  
> @@ -1440,7 +1439,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
>  	return -ENOMEM;
>  }
>  
> -static inline int virtqueue_add_packed(struct virtqueue *_vq,
> +static inline int virtqueue_add_packed(struct vring_virtqueue *vq,
>  				       struct scatterlist *sgs[],
>  				       unsigned int total_sg,
>  				       unsigned int out_sgs,
> @@ -1450,7 +1449,6 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
>  				       bool premapped,
>  				       gfp_t gfp)
>  {
> -	struct vring_virtqueue *vq = to_vvq(_vq);
>  	struct vring_packed_desc *desc;
>  	struct scatterlist *sg;
>  	unsigned int i, n, c, descs_used, err_idx, len;
> @@ -2262,9 +2260,9 @@ static inline int virtqueue_add(struct virtqueue *_vq,
>  {
>  	struct vring_virtqueue *vq = to_vvq(_vq);
>  
> -	return vq->packed_ring ? virtqueue_add_packed(_vq, sgs, total_sg,
> +	return vq->packed_ring ? virtqueue_add_packed(vq, sgs, total_sg,
>  					out_sgs, in_sgs, data, ctx, premapped, gfp) :
> -				 virtqueue_add_split(_vq, sgs, total_sg,
> +				 virtqueue_add_split(vq, sgs, total_sg,
>  					out_sgs, in_sgs, data, ctx, premapped, gfp);
>  }
>  
> -- 
> 2.31.1