Re: [Qemu-devel] [RFC v3 0/3] virtio-net: Add support to MTU feature

[Maxime Coquelin]

On 11/30/2016 12:23 PM, Jason Wang wrote:
> On 2016年11月30日 18:10, Maxime Coquelin wrote:
> > This series implements Virtio spec update from Aaron Conole which
> > defines a way for the host to expose its max MTU to the guest.
> >
> > This third version re-desings how MTU value is provided to QEMU.
> > Now, host_mtu parameter is added to provide QEMU with the MTU value,
> > and the backend, if supported, gets notified of the MTU value when the
> > MTU feature neogotiation succeeds.
> >
> > Only user backend currently supports MTU notification. A new protocol
> > feature has been implemented for sending MTU value to the backend.
> > Aaron, Kevin, Flavio, do you confirm this works for OVS if DPDK vhost lib
> > adds needed API to get the MTU value?
> >
> > For kernel backend, it is expected the management tool also configures
> > the tap/macvtap interface with same MTU value.
> > Daniel, I would be interrested about your feedback on this implementation
> > from management tool point of view.
>
> I believe we want management tool to configure both kernel and user
> backends.

Yes, I think you are right.

The vhost-user protocol feature would in this case be used to ensure
consistency.

Does that make sense, or we should just drop VHOST_USER_SET_MTU?

Thanks,
Maxime