Re: [PATCH 11/16] vhost: introduce restart and release for vhost_dev's vqs

[Jason Wang <jasowang@redhat.com>]

在 2022/7/18 19:17, Kangjie Xu 写道:
> Introduce vhost_dev_virtqueue_restart(), which can restart the
> virtqueue when the vhost has already started running.
>
> Meanwhile, vhost_dev_virtqueue_release(), which can ummap the
> vrings and the desc of a specific vq of a device.
>
> Combining the two functions, we can reset a virtqueue with a
> started vhost.
>
> Signed-off-by: Kangjie Xu <kangjie.xu@linux.alibaba.com>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>   hw/virtio/vhost.c         | 29 +++++++++++++++++++++++++++++
>   include/hw/virtio/vhost.h |  6 ++++++
>   2 files changed, 35 insertions(+)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index e467dfc7bc..d158d71866 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1904,3 +1904,32 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>   
>       return -ENOSYS;
>   }
> +
> +void vhost_dev_virtqueue_release(struct vhost_dev *hdev, VirtIODevice *vdev,
> +                                 int vq_index)
> +{
> +    int idx = vq_index - hdev->vq_index;
> +
> +    idx = hdev->vhost_ops->vhost_get_vq_index(hdev, idx);
> +
> +    vhost_virtqueue_unmap(hdev,
> +                          vdev,
> +                          hdev->vqs + idx,
> +                          hdev->vq_index + idx);
> +}


Anything wrong that makes you can't use vhost_virtqueue_stop() here?

Thanks


> +
> +int vhost_dev_virtqueue_restart(struct vhost_dev *hdev, VirtIODevice *vdev,
> +                                int vq_index)
> +{
> +    int idx = vq_index - hdev->vq_index;
> +    int r = 0;
> +
> +    idx = hdev->vhost_ops->vhost_get_vq_index(hdev, idx);
> +
> +    r = vhost_virtqueue_start(hdev,
> +                              vdev,
> +                              hdev->vqs + idx,
> +                              hdev->vq_index + idx);
> +
> +    return r;
> +}
> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> index a346f23d13..7df7dbe24d 100644
> --- a/include/hw/virtio/vhost.h
> +++ b/include/hw/virtio/vhost.h
> @@ -277,6 +277,12 @@ bool vhost_has_free_slot(void);
>   int vhost_net_set_backend(struct vhost_dev *hdev,
>                             struct vhost_vring_file *file);
>   
> +
> +void vhost_dev_virtqueue_release(struct vhost_dev *hdev, VirtIODevice *vdev,
> +                                 int vq_index);
> +int vhost_dev_virtqueue_restart(struct vhost_dev *hdev, VirtIODevice *vdev,
> +                                int vq_index);
> +
>   int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
>   
>   void vhost_dev_reset_inflight(struct vhost_inflight *inflight);