[PATCH v13 22/42] virtio_ring: packed: introduce virtqueue_reinit_packed()

[Jason Wang]

在 2022/7/26 15:22, Xuan Zhuo 写道:
> Introduce a function to initialize vq without allocating new ring,
> desc_state, desc_extra.
>
> Subsequent patches will call this function after reset vq to
> reinitialize vq.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>


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


> ---
>   drivers/virtio/virtio_ring.c | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 00b18cf3b4d9..7d4c444b5a9d 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -1957,6 +1957,27 @@ static void virtqueue_vring_attach_packed(struct vring_virtqueue *vq,
>   	vq->packed = *vring_packed;
>   }
>   
> +static void virtqueue_reinit_packed(struct vring_virtqueue *vq)
> +{
> +	int size, i;
> +
> +	memset(vq->packed.vring.device, 0, vq->packed.event_size_in_bytes);
> +	memset(vq->packed.vring.driver, 0, vq->packed.event_size_in_bytes);
> +	memset(vq->packed.vring.desc, 0, vq->packed.ring_size_in_bytes);
> +
> +	size = sizeof(struct vring_desc_state_packed) * vq->packed.vring.num;
> +	memset(vq->packed.desc_state, 0, size);
> +
> +	size = sizeof(struct vring_desc_extra) * vq->packed.vring.num;
> +	memset(vq->packed.desc_extra, 0, size);
> +
> +	for (i = 0; i < vq->packed.vring.num - 1; i++)
> +		vq->packed.desc_extra[i].next = i + 1;
> +
> +	virtqueue_init(vq, vq->packed.vring.num);
> +	virtqueue_vring_init_packed(&vq->packed, !!vq->vq.callback);
> +}
> +
>   static struct virtqueue *vring_create_virtqueue_packed(
>   	unsigned int index,
>   	unsigned int num,