Re: [PATCH v2 3/3] vhost_vdpa: move VIRTIO_NET_F_STATUS handling to vhost_net

[Michael S. Tsirkin]

On Fri, Oct 28, 2022 at 05:19:17PM +0200, Eugenio Pérez wrote:
> Since it is emulated on all vhost backends it makes sense to move it.
> 
> Although this feature can be emulated by qemu it benefits from
> information from the device. Ack it as long as the guest ack it.
> 
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

So I assume Jason's tree too?


> ---
>  hw/net/vhost_net.c | 13 +++++++++++++
>  net/vhost-vdpa.c   |  1 -
>  2 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index d28f8b974b..b533744211 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -127,8 +127,21 @@ int vhost_net_set_config(struct vhost_net *net, const 
> uint8_t *data,
>  
>  void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
>  {
> +    static const int status_feature_bit[] = {
> +        VIRTIO_NET_F_STATUS,
> +        VHOST_INVALID_FEATURE_BIT,
> +    };
> +
>      net->dev.acked_features = net->dev.backend_features;
>      vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
> +    if (net->dev.features & BIT_ULL(VIRTIO_NET_F_STATUS)) {
> +        /*
> +         * If device support _F_STATUS qemu should ack it so it reports link
> +         * status changes. If not supported qemu emulates it reporting an
> +         * always up link.
> +         */
> +        vhost_ack_features(&net->dev, status_feature_bit, features);
> +    }
>  }
>  
>  uint64_t vhost_net_get_max_queues(VHostNetState *net)
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 6d64000202..854b27186c 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -72,7 +72,6 @@ const int vdpa_feature_bits[] = {
>      VIRTIO_NET_F_RSS,
>      VIRTIO_NET_F_HASH_REPORT,
>      VIRTIO_NET_F_GUEST_ANNOUNCE,
> -    VIRTIO_NET_F_STATUS,
>      VHOST_INVALID_FEATURE_BIT
>  };
>  
> -- 
> 2.31.1