[PATCH v7 14/26] virtio: add helper for queue reset

[Xuan Zhuo]

On Wed, 9 Mar 2022 16:48:28 +0800, Jason Wang <jasowang at redhat.com> wrote:
>
> 在 2022/3/8 下午8:35, Xuan Zhuo 写道:
> > Add helper for virtio queue reset.
> >
> > * virtio_reset_vq(): reset a queue individually
> > * virtio_enable_resetq(): enable a reset queue
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
> > ---
> >   include/linux/virtio_config.h | 40 +++++++++++++++++++++++++++++++++++
> >   1 file changed, 40 insertions(+)
> >
> > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
> > index d51906b1389f..0b81fbe17c85 100644
> > --- a/include/linux/virtio_config.h
> > +++ b/include/linux/virtio_config.h
> > @@ -230,6 +230,46 @@ int virtio_find_vqs_ctx(struct virtio_device *vdev, unsigned nvqs,
> >   				      desc);
> >   }
> >
> > +/**
> > + * virtio_reset_vq - reset a queue individually
> > + * @vq: the virtqueue
> > + *
> > + * returns 0 on success or error status
> > + *
> > + * The api process of reset under normal circumstances:
> > + *	1. virtio_reset_vq()              - notify the device to reset the queue
> > + *	2. virtqueue_detach_unused_buf()  - recycle the buffer submitted
> > + *	3. virtqueue_reset_vring()        - reset the vring (may re-alloc)
> > + *	4. virtio_enable_resetq()         - mmap vring to device, and enable the queue
> > + *
> > + * Caller should guarantee that the vring is not accessed by any functions
> > + * of virtqueue.
> > + */
> > +static inline
> > +int virtio_reset_vq(struct virtqueue *vq)
> > +{
>
>
> It looks to me the prefix "virtio" is used for the device specific
> operations.
>
> I wonder if it's better to rename this as virtqueue_reste() and move it
> to virtio_ring.c?

Call vq->vdev->config->reset_vq in virtio_ring.c?

If it fits, I think it's fine.

Thanks.

>
> Thanks
>
>
> > +	if (!vq->vdev->config->reset_vq)
> > +		return -ENOENT;
> > +
> > +	return vq->vdev->config->reset_vq(vq);
> > +}
> > +
> > +/**
> > + * virtio_enable_resetq - enable a reset queue
> > + * @vq: the virtqueue
> > + *
> > + * returns 0 on success or error status
> > + *
> > + */
> > +static inline
> > +int virtio_enable_resetq(struct virtqueue *vq)
> > +{
> > +	if (!vq->vdev->config->enable_reset_vq)
> > +		return -ENOENT;
> > +
> > +	return vq->vdev->config->enable_reset_vq(vq);
> > +}
> > +
> >   /**
> >    * virtio_device_ready - enable vq use in probe function
> >    * @vdev: the device
>