[PATCH v2 11/11] iommufd: Allow iommufd to supply /dev/vfio/vfio

[Tian, Kevin]

> From: Jason Gunthorpe <jgg at nvidia.com>
> Sent: Tuesday, November 8, 2022 8:53 AM
> 
> If the VFIO container is compiled out, give a kconfig option for iommufd
> to provide the miscdev node with the same name and permissions as vfio
> uses.
> 
> The compatibility node supports the same ioctls as VFIO and automatically
> enables the VFIO compatible pinned page accounting mode.
> 
> Tested-by: Nicolin Chen <nicolinc at nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>

Reviewed-by: Kevin Tian <kevin.tian at intel.com>