[PATCH v12 24/40] virtio: allow to unbreak/break virtqueue individually

[Jason Wang]

在 2022/7/20 11:04, Xuan Zhuo 写道:
> This patch allows the new introduced
> __virtqueue_break()/__virtqueue_unbreak() to break/unbreak the
> virtqueue.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>


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


> ---
>   drivers/virtio/virtio_ring.c | 24 ++++++++++++++++++++++++
>   include/linux/virtio.h       |  3 +++
>   2 files changed, 27 insertions(+)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index cf4379175163..bf666dad9904 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -2730,6 +2730,30 @@ unsigned int virtqueue_get_vring_size(struct virtqueue *_vq)
>   }
>   EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
>   
> +/*
> + * This function should only be called by the core, not directly by the driver.
> + */
> +void __virtqueue_break(struct virtqueue *_vq)
> +{
> +	struct vring_virtqueue *vq = to_vvq(_vq);
> +
> +	/* Pairs with READ_ONCE() in virtqueue_is_broken(). */
> +	WRITE_ONCE(vq->broken, true);
> +}
> +EXPORT_SYMBOL_GPL(__virtqueue_break);
> +
> +/*
> + * This function should only be called by the core, not directly by the driver.
> + */
> +void __virtqueue_unbreak(struct virtqueue *_vq)
> +{
> +	struct vring_virtqueue *vq = to_vvq(_vq);
> +
> +	/* Pairs with READ_ONCE() in virtqueue_is_broken(). */
> +	WRITE_ONCE(vq->broken, false);
> +}
> +EXPORT_SYMBOL_GPL(__virtqueue_unbreak);
> +
>   bool virtqueue_is_broken(struct virtqueue *_vq)
>   {
>   	struct vring_virtqueue *vq = to_vvq(_vq);
> diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> index 62e31bca5602..d45ee82a4470 100644
> --- a/include/linux/virtio.h
> +++ b/include/linux/virtio.h
> @@ -138,6 +138,9 @@ bool is_virtio_device(struct device *dev);
>   void virtio_break_device(struct virtio_device *dev);
>   void __virtio_unbreak_device(struct virtio_device *dev);
>   
> +void __virtqueue_break(struct virtqueue *_vq);
> +void __virtqueue_unbreak(struct virtqueue *_vq);
> +
>   void virtio_config_changed(struct virtio_device *dev);
>   #ifdef CONFIG_PM_SLEEP
>   int virtio_device_freeze(struct virtio_device *dev);