Re: [PATCH 1/2] virito: introduce methods of fixing device features

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

On Thu, 13 Nov 2014 17:11:30 +0800
Jason Wang <jasowang@redhat.com> wrote:

> On 11/13/2014 04:46 PM, Cornelia Huck wrote:
> > On Thu, 13 Nov 2014 13:52:53 +0800
> > Jason Wang <jasowang@redhat.com> wrote:

> >> +static inline void virtio_disable_feature(struct virtio_device *vdev,
> >> +                                          unsigned int fbit)
> >> +{
> >> +	BUG_ON(fbit >= VIRTIO_TRANSPORT_F_START);
> >> +	BUG_ON(vdev->config->get_status(vdev) &
> >> +	       ~(VIRTIO_CONFIG_S_ACKNOWLEDGE | VIRTIO_CONFIG_S_DRIVER));
> > When we add virtio-1 support, we can add a check for FEATURES_OK here,
> > so we're really on the safe side.
> >
> 
> If I read the spec correctly, FEATURES_OK was set only after writing the
> features bits to device. But we want to sanitize the them before.

I meant doing a BUG when FEATURES_OK is set - sorry for not being clear.