Re: [PATCH v2 1/3] virtio: add ability to delete vq through a pointer

[Pankaj Gupta <pagupta@redhat.com>]

> From: Pan Nengyuan <pannengyuan@huawei.com>
> 
> Devices tend to maintain vq pointers, allow deleting them trough a vq
> pointer.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
> ---
> Changes v2 to v1:
> - add a new function virtio_delete_queue to cleanup vq through a vq pointer
> ---
>  hw/virtio/virtio.c         | 16 +++++++++++-----
>  include/hw/virtio/virtio.h |  2 ++
>  2 files changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 04716b5..6de3cfd 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -2330,17 +2330,23 @@ VirtQueue *virtio_add_queue(VirtIODevice *vdev, int
> queue_size,
>      return &vdev->vq[i];
>  }
>  
> +void virtio_delete_queue(VirtQueue *vq)
> +{
> +    vq->vring.num = 0;
> +    vq->vring.num_default = 0;
> +    vq->handle_output = NULL;
> +    vq->handle_aio_output = NULL;
> +    g_free(vq->used_elems);
> +    vq->used_elems = NULL;
> +}
> +
>  void virtio_del_queue(VirtIODevice *vdev, int n)
>  {
>      if (n < 0 || n >= VIRTIO_QUEUE_MAX) {
>          abort();
>      }
>  
> -    vdev->vq[n].vring.num = 0;
> -    vdev->vq[n].vring.num_default = 0;
> -    vdev->vq[n].handle_output = NULL;
> -    vdev->vq[n].handle_aio_output = NULL;
> -    g_free(vdev->vq[n].used_elems);
> +    virtio_delete_queue(&vdev->vq[n]);
>  }
>  
>  static void virtio_set_isr(VirtIODevice *vdev, int value)
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index c32a815..e18756d 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -183,6 +183,8 @@ VirtQueue *virtio_add_queue(VirtIODevice *vdev, int
> queue_size,
>  
>  void virtio_del_queue(VirtIODevice *vdev, int n);
>  
> +void virtio_delete_queue(VirtQueue *vq);
> +
>  void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
>                      unsigned int len);
>  void virtqueue_flush(VirtQueue *vq, unsigned int count);
> --
> 2.7.2.windows.1
> 
> 
Overall it ooks good to me.

Just one point: e.g in virtio_rng: "virtio_rng_device_unrealize" function
We are doing :     virtio_del_queue(vdev, 0);

One can directly call "virtio_delete_queue". It can become confusing
to call multiple functions for same purpose. Instead, Can we make 
"virtio_delete_queue" static inline?

Other than that:
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>

> 
>