> From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > Sent: Thursday, March 16, 2023 8:55 PM > > +void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev) > +{ > + lockdep_assert_held(&vdev->dev_set->lock); > + > + if (WARN_ON(!vdev->iommufd_device) || !vdev->iommufd_attached) > + return; > + the 2nd check shouldn't be a WARN_ON. It's user-triggerable.