On Fri, 3 Feb 2023 04:05:38 -0500, "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote:
> On Thu, Feb 02, 2023 at 07:00:31PM +0800, Xuan Zhuo wrote:
> > Introduce virtqueue_reset() to release all buffer inside vq.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> > ---
> > drivers/virtio/virtio_ring.c | 50 ++++++++++++++++++++++++++++++++++++
> > include/linux/virtio.h | 2 ++
> > 2 files changed, 52 insertions(+)
> >
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index e32046fd15a5..7dfce7001f9f 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -2735,6 +2735,56 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
> > }
> > EXPORT_SYMBOL_GPL(virtqueue_resize);
> >
> > +/**
> > + * virtqueue_reset - reset the vring of vq
>
> ..., detach and recycle all unused buffers
>
> after all this is why we are doing this reset, right?
>
> > + * @_vq: the struct virtqueue we're talking about.
> > + * @recycle: callback for recycle the useless buffer
>
> not useless :) unused:
>
> callback to recycle unused buffers
I agree. Will fix.
Thanks.
>
> I know we have the same confusion in virtqueue_resize, I will fix
> that.
>
> > + *
> > + * Caller must ensure we don't call this with other virtqueue operations
> > + * at the same time (except where noted).
> > + *
> > + * Returns zero or a negative error.
> > + * 0: success.
> > + * -EBUSY: Failed to sync with device, vq may not work properly
> > + * -ENOENT: Transport or device not supported
> > + * -EPERM: Operation not permitted
> > + */
> > +int virtqueue_reset(struct virtqueue *_vq,
> > + void (*recycle)(struct virtqueue *vq, void *buf))
> > +{
> > + struct vring_virtqueue *vq = to_vvq(_vq);
> > + struct virtio_device *vdev = vq->vq.vdev;
> > + void *buf;
> > + int err;
> > +
> > + if (!vq->we_own_ring)
> > + return -EPERM;
> > +
> > + if (!vdev->config->disable_vq_and_reset)
> > + return -ENOENT;
> > +
> > + if (!vdev->config->enable_vq_after_reset)
> > + return -ENOENT;
> > +
> > + err = vdev->config->disable_vq_and_reset(_vq);
> > + if (err)
> > + return err;
> > +
> > + while ((buf = virtqueue_detach_unused_buf(_vq)) != NULL)
> > + recycle(_vq, buf);
> > +
> > + if (vq->packed_ring)
> > + virtqueue_reinit_packed(vq);
> > + else
> > + virtqueue_reinit_split(vq);
> > +
> > + if (vdev->config->enable_vq_after_reset(_vq))
> > + return -EBUSY;
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(virtqueue_reset);
> > +
> > /* Only available for split ring */
> > struct virtqueue *vring_new_virtqueue(unsigned int index,
> > unsigned int num,
> > diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> > index 3ebb346ebb7c..3ca2edb1aef3 100644
> > --- a/include/linux/virtio.h
> > +++ b/include/linux/virtio.h
> > @@ -105,6 +105,8 @@ dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq);
> >
> > int virtqueue_resize(struct virtqueue *vq, u32 num,
> > void (*recycle)(struct virtqueue *vq, void *buf));
> > +int virtqueue_reset(struct virtqueue *vq,
> > + void (*recycle)(struct virtqueue *vq, void *buf));
> >
> > /**
> > * struct virtio_device - representation of a device using virtio
> > --
> > 2.32.0.3.g01195cf9f
>
