Re: [PATCH v9 06/32] virtio_ring: split: extract the logic of alloc queue

Jason Wang
2022-04-12T03:22:56Z

在 2022/4/6 上午11:43, Xuan Zhuo 写道:
> Separate the logic of split to create vring queue.
>
> This feature is required for subsequent virtuqueue reset vring.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
> drivers/virtio/virtio_ring.c | 53 ++++++++++++++++++++++++------------
> 1 file changed, 36 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 33fddfb907a6..72d5ae063fa0 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -915,23 +915,15 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
> return NULL;
> }
>
> -static struct virtqueue *vring_create_virtqueue_split(
> - unsigned int index,
> - unsigned int num,
> - unsigned int vring_align,
> - struct virtio_device *vdev,
> - bool weak_barriers,
> - bool may_reduce_num,
> - bool context,
> - bool (*notify)(struct virtqueue *),
> - void (*callback)(struct virtqueue *),
> - const char *name)
> +static void *vring_alloc_queue_split(struct virtio_device *vdev,
> + dma_addr_t *dma_addr,
> + u32 *n,
> + unsigned int vring_align,
> + bool weak_barriers,

This is not used in this function.

Thanks

> + bool may_reduce_num)
> {
> - struct virtqueue *vq;
> void *queue = NULL;
> - dma_addr_t dma_addr;
> - size_t queue_size_in_bytes;
> - struct vring vring;
> + u32 num = *n;
>
> /* We assume num is a power of 2. */
> if (num & (num - 1)) {
> @@ -942,7 +934,7 @@ static struct virtqueue *vring_create_virtqueue_split(
> /* TODO: allocate each queue chunk individually */
> for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) {
> queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
> - &dma_addr,
> + dma_addr,
> GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
> if (queue)
> break;
> @@ -956,11 +948,38 @@ static struct virtqueue *vring_create_virtqueue_split(
> if (!queue) {
> /* Try to get a single page. You are my only hope! */
> queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
> - &dma_addr, GFP_KERNEL|__GFP_ZERO);
> + dma_addr, GFP_KERNEL|__GFP_ZERO);
> }
> if (!queue)
> return NULL;
>
> + *n = num;
> + return queue;
> +}
> +
> +static struct virtqueue *vring_create_virtqueue_split(
> + unsigned int index,
> + unsigned int num,
> + unsigned int vring_align,
> + struct virtio_device *vdev,
> + bool weak_barriers,
> + bool may_reduce_num,
> + bool context,
> + bool (*notify)(struct virtqueue *),
> + void (*callback)(struct virtqueue *),
> + const char *name)
> +{
> + size_t queue_size_in_bytes;
> + struct virtqueue *vq;
> + dma_addr_t dma_addr;
> + struct vring vring;
> + void *queue;
> +
> + queue = vring_alloc_queue_split(vdev, &dma_addr, &num, vring_align,
> + weak_barriers, may_reduce_num);
> + if (!queue)
> + return NULL;
> +
> queue_size_in_bytes = vring_size(num, vring_align);
> vring_init(&vring, num, queue, vring_align);
>