[PATCH v11 10/40] virtio_ring: split: extract the logic of attach vring

[Jason Wang]

在 2022/6/29 14:56, Xuan Zhuo 写道:
> Separate the logic of attach vring, subsequent patches will call it
> separately.
>
> Since the "struct vring_virtqueue_split split" is created on the
> stack and has been initialized to 0. So using
> split->queue_dma_addr/split->queue_size_in_bytes assignment for
> queue_dma_addr/queue_size_in_bytes can keep the same as the original
> code.
>
> On the other hand, subsequent patches can use the "struct
> vring_virtqueue_split split" obtained by vring_alloc_queue_split() to
> directly complete the attach operation.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>


Acked-by: Jason Wang <jasowang at redhat.com>


> ---
>   drivers/virtio/virtio_ring.c | 20 +++++++++++++-------
>   1 file changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index cedd340d6db7..9025bd373d3b 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -940,6 +940,18 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
>   	return NULL;
>   }
>   
> +static void virtqueue_vring_attach_split(struct vring_virtqueue *vq,
> +					 struct vring_virtqueue_split *vring)
> +{
> +	vq->split.queue_dma_addr = vring->queue_dma_addr;
> +	vq->split.queue_size_in_bytes = vring->queue_size_in_bytes;
> +
> +	vq->split.vring = vring->vring;
> +
> +	vq->split.desc_state = vring->desc_state;
> +	vq->split.desc_extra = vring->desc_extra;
> +}
> +
>   static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring)
>   {
>   	struct vring_desc_state_split *state;
> @@ -2287,10 +2299,6 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   	vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
>   		!context;
>   
> -	vq->split.queue_dma_addr = 0;
> -	vq->split.queue_size_in_bytes = 0;
> -
> -	vq->split.vring = _vring;
>   	vq->split.avail_flags_shadow = 0;
>   	vq->split.avail_idx_shadow = 0;
>   
> @@ -2310,10 +2318,8 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   		return NULL;
>   	}
>   
> -	vq->split.desc_state = vring.desc_state;
> -	vq->split.desc_extra = vring.desc_extra;
> -
>   	virtqueue_init(vq, vring.vring.num);
> +	virtqueue_vring_attach_split(vq, &vring);
>   
>   	spin_lock(&vdev->vqs_list_lock);
>   	list_add_tail(&vq->vq.list, &vdev->vqs);