Re: [Qemu-devel] [PATCH for-3.2 01/11] vhost-user: define conventions for vhost-user backends

["Marc-André Lureau" <marcandre.lureau@gmail.com>]

Hi

On Wed, Jan 9, 2019 at 12:45 PM Hoffmann, Gerd <kraxel@redhat.com> wrote:
>
>   Hi,
>
> > Unfortunately, vdev is not set before vhost_dev_start().
> >
> > We could add the migration blocker there somehow?
>
> Sure.  Just use migrate_add_blocker() to do that at any time (see qxl.c
> for an example).

VhostUserInput inherits from VirtioInput, which implements vmsd.

The "Add vhost-user-input-pci" patch override the DeviceClass vmsd to
set it as unmigratable. If I understand correctly, Michael suggested
to add a check for device vmsd == NULL in hw/virtio/vhost-user.c
instead.

However, vhost-user devices would still need to overwrite vmsd to NULL.

I don't think there is a benefit in the generic vmsd == NULL check, as
you still need not to forget to overwrite vmsd to NULL in the
vhost-user device.

Am I missing something?

-- 
Marc-André Lureau