> From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > Sent: Tuesday, February 21, 2023 11:48 AM > > + > +void vfio_device_unblock_group(struct vfio_device *device) > +{ > + struct vfio_group *group = device->group; > + > + mutex_lock(&group->group_lock); > + group->cdev_device_open_cnt--; > + mutex_unlock(&group->group_lock); > +} > + Add a WARN_ON(group->cdev_device_open_cnt) in vfio_group_release(). with that: Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>