Re: [Qemu-devel] [RFC] vhost-user: don't ignore CTRL_VLAN feature

[Tiwei Bie <tiwei.bie@intel.com>]

On Tue, Jun 11, 2019 at 03:22:47PM +0800, Jason Wang wrote:
> 
> On 2019/6/11 下午2:51, Tiwei Bie wrote:
> > The VIRTIO_NET_F_CTRL_VLAN feature requires the support of
> > vhost-user backend. But it will be advertised to guest driver
> > as long as it's enabled by users in QEMU, while it's not
> > supported by vhost-user backend. This patch fixes this issue.
> > 
> > Fixes: 72018d1e1917 ("vhost-user: ignore qemu-only features")
> 
> 
> My understanding is if may want to revert this patch.
> 
> 
> > Cc: qemu-stable@nongnu.org
> > 
> > Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> > ---
> > It's not clear in the spec that, whether vlan filtering is
> > also best-effort:
> > https://github.com/oasis-tcs/virtio-spec/blob/37057052e7/content.tex#L3372
> 
> 
> It should be a bug of the code, we should consider to implement ctrl command
> for vhost-user.

Yeah, we need to pass these information to backends if we
want to make it possible to support it in vhost-user.


> 
> Thanks
> 
> 
> > 
> >   hw/net/vhost_net.c | 2 ++
> >   1 file changed, 2 insertions(+)
> > 
> > diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> > index a6b719035c..1444fc9230 100644
> > --- a/hw/net/vhost_net.c
> > +++ b/hw/net/vhost_net.c
> > @@ -75,6 +75,8 @@ static const int user_feature_bits[] = {
> >       VIRTIO_NET_F_MTU,
> >       VIRTIO_F_IOMMU_PLATFORM,
> > +    VIRTIO_NET_F_CTRL_VLAN,
> > +
> >       /* This bit implies RARP isn't sent by QEMU out of band */
> >       VIRTIO_NET_F_GUEST_ANNOUNCE,