> From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> Sent: Wednesday, March 8, 2023 9:14 PM
>
> After making the no-DMA drivers (samples/vfio-mdev) providing iommufd
> callbacks, __vfio_register_dev() should check the presence of the iommufd
> callbacks if CONFIG_IOMMUFD is enabled.
>
> Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
> ---
> drivers/vfio/vfio_main.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 43bd6b76e2b6..89497c933490 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -255,8 +255,9 @@ static int __vfio_register_dev(struct vfio_device
> *device,
> {
> int ret;
>
> - if (WARN_ON(device->ops->bind_iommufd &&
> - (!device->ops->unbind_iommufd ||
> + if (WARN_ON(IS_ENABLED(CONFIG_IOMMUFD) &&
> + (!device->ops->bind_iommufd ||
> + !device->ops->unbind_iommufd ||
> !device->ops->attach_ioas)))
> return -EINVAL;
>
I don't think IS_ENABLED() check is necessary. those ops are
defined in the driver side w/o a conditional CONFIG_IOMMUFD.
We should warn out lacking of those ops to the driver developer
as early as possible, instead of postponing it until someone
starts to build kernel with CONFIG_IOMMUFD.
