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 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
