On Mon, Feb 8, 2021 at 5:15 AM Jason Wang <jasow...@redhat.com> wrote: > > > On 2021/2/5 下午9:38, Michael S. Tsirkin wrote: > > On Thu, Feb 04, 2021 at 10:29:15PM +0200, Yuri Benditovich wrote: > >> Currently virtio-net silently clears features if they are > >> not supported by respective vhost. This may create migration > >> problems in future if vhost features on the source and destination > >> are different. Implement graceful fallback to no-vhost mode > >> when some acked features contradict with vhost. The decision is > >> taken on set_features call and the vhost will be disabled > >> till next reset (or migration). > >> Such fallback is currently enabled only for TAP netdev. > >> > >> Signed-off-by: Yuri Benditovich<yuri.benditov...@daynix.com> > > Sounds good, but I don't think we should do this if > > vhostforce=on is set. > > > If we do this, does it mean we won't maintain migration compatibility > when vhostforce is on?
AFAIU, the 'vhostforce=on' should mean the vhost can't be disabled (if I'm not mistaken this is typically used for vhost-user). So we can view this case as similar to vhost-vdpa and vhost-user. > > Thanks > > > > > > Also, let's document this behaviour with the vhost option so people > > are not suprized. > > >
