[PATCH v12 02/40] virtio: struct virtio_config_ops add callbacks for queue_reset

[Jason Wang]

在 2022/7/20 11:03, Xuan Zhuo 写道:
> reset can be divided into the following four steps (example):
>   1. transport: notify the device to reset the queue
>   2. vring:     recycle the buffer submitted
>   3. vring:     reset/resize the vring (may re-alloc)
>   4. transport: mmap vring to device, and enable the queue
>
> In order to support queue reset, add two callbacks in struct
> virtio_config_ops to implement steps 1 and 4.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>


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


> ---
>   include/linux/virtio_config.h | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
>
> diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
> index b47c2e7ed0ee..36ec7be1f480 100644
> --- a/include/linux/virtio_config.h
> +++ b/include/linux/virtio_config.h
> @@ -78,6 +78,18 @@ struct virtio_shm_region {
>    * @set_vq_affinity: set the affinity for a virtqueue (optional).
>    * @get_vq_affinity: get the affinity for a virtqueue (optional).
>    * @get_shm_region: get a shared memory region based on the index.
> + * @disable_vq_and_reset: reset a queue individually (optional).
> + *	vq: the virtqueue
> + *	Returns 0 on success or error status
> + *	disable_vq_and_reset will guarantee that the callbacks are disabled and
> + *	synchronized.
> + *	Except for the callback, the caller should guarantee that the vring is
> + *	not accessed by any functions of virtqueue.
> + * @enable_vq_after_reset: enable a reset queue
> + *	vq: the virtqueue
> + *	Returns 0 on success or error status
> + *	If disable_vq_and_reset is set, then enable_vq_after_reset must also be
> + *	set.
>    */
>   typedef void vq_callback_t(struct virtqueue *);
>   struct virtio_config_ops {
> @@ -104,6 +116,8 @@ struct virtio_config_ops {
>   			int index);
>   	bool (*get_shm_region)(struct virtio_device *vdev,
>   			       struct virtio_shm_region *region, u8 id);
> +	int (*disable_vq_and_reset)(struct virtqueue *vq);
> +	int (*enable_vq_after_reset)(struct virtqueue *vq);
>   };
>   
>   /* If driver didn't advertise the feature, it will never appear. */