Re: [PATCH v4 08/11] vdpa: Add eventfd for the vdpa callback

[Jason Wang <jasowang@redhat.com>]

在 2023/3/23 13:30, Xie Yongji 写道:
> Add eventfd for the vdpa callback so that user
> can signal it directly instead of triggering the
> callback. It will be used for vhost-vdpa case.
>
> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>


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

Thanks


> ---
>   drivers/vhost/vdpa.c         | 2 ++
>   drivers/virtio/virtio_vdpa.c | 1 +
>   include/linux/vdpa.h         | 6 ++++++
>   3 files changed, 9 insertions(+)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 7be9d9d8f01c..9cd878e25cff 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -599,9 +599,11 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
>   		if (vq->call_ctx.ctx) {
>   			cb.callback = vhost_vdpa_virtqueue_cb;
>   			cb.private = vq;
> +			cb.trigger = vq->call_ctx.ctx;
>   		} else {
>   			cb.callback = NULL;
>   			cb.private = NULL;
> +			cb.trigger = NULL;
>   		}
>   		ops->set_vq_cb(vdpa, idx, &cb);
>   		vhost_vdpa_setup_vq_irq(v, idx);
> diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
> index f3826f42b704..2a095f37f26b 100644
> --- a/drivers/virtio/virtio_vdpa.c
> +++ b/drivers/virtio/virtio_vdpa.c
> @@ -196,6 +196,7 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
>   	/* Setup virtqueue callback */
>   	cb.callback = callback ? virtio_vdpa_virtqueue_cb : NULL;
>   	cb.private = info;
> +	cb.trigger = NULL;
>   	ops->set_vq_cb(vdpa, index, &cb);
>   	ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq));
>   
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index e52c9a37999c..0372b2e3d38a 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -13,10 +13,16 @@
>    * struct vdpa_calllback - vDPA callback definition.
>    * @callback: interrupt callback function
>    * @private: the data passed to the callback function
> + * @trigger: the eventfd for the callback (Optional).
> + *           When it is set, the vDPA driver must guarantee that
> + *           signaling it is functional equivalent to triggering
> + *           the callback. Then vDPA parent can signal it directly
> + *           instead of triggering the callback.
>    */
>   struct vdpa_callback {
>   	irqreturn_t (*callback)(void *data);
>   	void *private;
> +	struct eventfd_ctx *trigger;
>   };
>   
>   /**