Re: [PATCH net V5] virtio-net: validate features during probe

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Thu, 20 Nov 2014 17:03:05 +0800
Jason Wang <jasowang@redhat.com> wrote:

> We currently trigger BUG when VIRTIO_NET_F_CTRL_VQ
> is not set but one of features depending on it is.
> That's not a friendly way to report errors to
> hypervisors.
> Let's check, and fail probe instead.
> 
> Cc: Rusty Russell <rusty@rustcorp.com.au>
> Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
> Cc: Wanlong Gao <gaowanlong@cn.fujitsu.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>

> +static bool virtnet_validate_features(struct virtio_device *vdev)
> +{
> +	if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
> +	    (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
> +			     "VIRTIO_NET_F_CTRL_VQ") ||
> +	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
> +			     "VIRTIO_NET_F_CTRL_VQ") ||
> +	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
> +			     "VIRTIO_NET_F_CTRL_VQ") ||
> +	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
> +	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
> +			     "VIRTIO_NET_F_CTRL_VQ"))) {
> +		return false;
> +	}
> +
> +	return true;
> +}

I still think it may make sense to print all incorrectly set bits, but
let's just fix the BUG() trigger for now.

Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>