RE: [PATCH v2 09/14] vfio-iommufd: Add detach_ioas support for physical VFIO devices

Liu, Yi L
2023-02-07T08:56:55Z

> From: Tian, Kevin <kevin.tian@intel.com>
> Sent: Tuesday, February 7, 2023 2:07 PM
>
> > From: Liu, Yi L <yi.l.liu@intel.com>
> > Sent: Monday, February 6, 2023 5:05 PM
> >
> > +static void __vfio_iommufd_detach(struct vfio_device *vdev)
> > +{
> > + iommufd_device_detach(vdev->iommufd_device);
> > + vdev->iommufd_attached = false;
> > +}
> > +
> > void vfio_iommufd_physical_unbind(struct vfio_device *vdev)
> > {
> > lockdep_assert_held(&vdev->dev_set->lock);
> >
> > - if (vdev->iommufd_attached) {
> > - iommufd_device_detach(vdev->iommufd_device);
> > - vdev->iommufd_attached = false;
> > - }
> > + if (vdev->iommufd_attached)
> > + __vfio_iommufd_detach(vdev);
>
> I'm not sure whether this abstraction really improves things.
>
> Just two callers. and the old code reads clearer to me which
> checks a flag, does something and then clear the flag.

Ok. Will revert it.

>
> > @@ -74,6 +74,7 @@ struct vfio_device {
> > * @unbind_iommufd: Opposite of bind_iommufd
> > * @attach_ioas: Called when attaching device to an IOAS/HWPT
> managed
> > by the
> > * bound iommufd. Undo in unbind_iommufd.
>
> "Undo in unbind_iommufd if @detach_ioas is not called".
>
> > + * @detach_ioas: Opposite of attach_ioas, this is for runtime undo.
>
> remove "this is for runtime undo" which is confusing.

Ok, clear with your above suggestion.

Regards,
Yi Liu