Re: [Qemu-devel] [[RFC v3 12/12] virtio: feature vhost-net support for packed ring

[Jason Wang]

On 2018年10月11日 22:08, address@hidden wrote:
> From: Wei Xu <address@hidden>
>
> (cherry picked from commit 305a2c4640c15c5717245067ab937fd10f478ee6)
> Signed-off-by: Wei Xu <address@hidden>
> (cherry picked from commit 46476dae6f44c6fef8802a4a0ac7d0d79fe399e3)
> Signed-off-by: Wei Xu <address@hidden>

The cherry-pick tag looks odd.

> ---
>   hw/virtio/vhost.c          | 3 +++
>   hw/virtio/virtio.c         | 4 ++++
>   include/hw/virtio/virtio.h | 1 +
>   3 files changed, 8 insertions(+)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 9df2da3..de06d55 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -974,6 +974,9 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
>       }
>   
>       state.num = virtio_queue_get_last_avail_idx(vdev, idx);
> +    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
> +        state.num |= ((int)virtio_queue_packed_get_wc(vdev, idx)) << 31;
> +    }

We decide to use bit 15 instead.

And please refer the recent discussion for the agreement.

Thanks

>       r = dev->vhost_ops->vhost_set_vring_base(dev, &state);
>       if (r) {
>           VHOST_OPS_DEBUG("vhost_set_vring_base failed");
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 1d25776..2a90163 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -2894,6 +2894,10 @@ void virtio_init(VirtIODevice *vdev, const char *name,
>       vdev->use_guest_notifier_mask = true;
>   }
>   
> +bool virtio_queue_packed_get_wc(VirtIODevice *vdev, int n)
> +{
> +    return vdev->vq[n].avail_wrap_counter;
> +}
>   hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n)
>   {
>       return vdev->vq[n].vring.desc;
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index 9af8839..0bb3be5 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -295,6 +295,7 @@ void virtio_queue_aio_set_host_notifier_handler(VirtQueue 
> *vq, AioContext *ctx,
>                                                   VirtIOHandleAIOOutput 
> handle_output);
>   VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
>   VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
> +bool virtio_queue_packed_get_wc(VirtIODevice *vdev, int n);
>   
>   static inline void virtio_add_feature(uint64_t *features, unsigned int fbit)
>   {