Re: [PATCH v2 09/13] vdpa net: block migration if the device has CVQ

[Eugenio Perez Martin]

On Wed, Feb 22, 2023 at 5:01 AM Jason Wang <jasowang@redhat.com> wrote:
>
>
> 在 2023/2/8 17:42, Eugenio Pérez 写道:
> > Devices with CVQ needs to migrate state beyond vq state.  Leaving this
> > to future series.
>
>
> I may miss something but what is missed to support CVQ/MQ?
>

To restore all the device state set by CVQ in the migration source
(MAC, MQ, ...) before data vqs start. We don't have a reliable way to
not start data vqs until the device [1].

Thanks!

[1] https://lists.gnu.org/archive/html/qemu-devel/2023-01/msg02652.html

> Thanks
>
>
> >
> > Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> > ---
> >   net/vhost-vdpa.c | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> > index bca13f97fd..309861e56c 100644
> > --- a/net/vhost-vdpa.c
> > +++ b/net/vhost-vdpa.c
> > @@ -955,11 +955,17 @@ int net_init_vhost_vdpa(const Netdev *netdev, const 
> > char *name,
> >       }
> >
> >       if (has_cvq) {
> > +        VhostVDPAState *s;
> > +
> >           nc = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
> >                                    vdpa_device_fd, i, 1, false,
> >                                    opts->x_svq, iova_range);
> >           if (!nc)
> >               goto err;
> > +
> > +        s = DO_UPCAST(VhostVDPAState, nc, nc);
> > +        error_setg(&s->vhost_vdpa.dev->migration_blocker,
> > +                   "net vdpa cannot migrate with MQ feature");
> >       }
> >
> >       return 0;
>