Re: [PATCH v13 21/22] vfio: Compile vfio_group infrastructure optionally

Jason Gunthorpe
2023-07-17T12:34:05Z

On Mon, Jul 17, 2023 at 06:36:19AM +0000, Liu, Yi L wrote:
> Hi Alex, Jason,
>
> I found a minor nit on the kconfig. The below configuration is valid.
> But user cannot use vfio directly as there is no /dev/vfio/vfio. Although
> user can open /dev/iommu instead. This is not good.
>
> CONFIG_IOMMUFD=y
> CONFIG_VFIO_DEVICE_CDEv=n
> CONFIG_VFIO_GROUP=y
> CONFIG_VFIO_CONTAINER=n
> CONFIG_IOMMUFD_VFIO_CONTAINER=n
>
> So need to have the below change. I'll incorporate this change in
> this series after your ack.

This is fine, we decided to allow this in the original vfio series. It
is usable in that you have to use iommufd natively with the group
interface. It won't be backwards compatible with current userspace.

Jason