[PATCH v2 08/11] vfio-iommufd: Support iommufd for emulated VFIO devices

[Tian, Kevin]

> From: Jason Gunthorpe <jgg at nvidia.com>
> Sent: Tuesday, November 8, 2022 8:53 AM
> 
> Emulated VFIO devices are calling vfio_register_emulated_iommu_dev() and
> consist of all the mdev drivers.
> 
> Like the physical drivers, support for iommufd is provided by the driver
> supplying the correct standard ops. Provide ops from the core that
> duplicate what vfio_register_emulated_iommu_dev() does.
> 
> Emulated drivers are where it is more likely to see variation in the
> iommfd support ops. For instance IDXD will probably need to setup both a
> iommfd_device context linked to a PASID and an iommufd_access context to
> support all their mdev operations.
> 
> Tested-by: Nicolin Chen <nicolinc at nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>

this looks good to me overall. but I'll wait for next version to ack
after the change for s390 is settled down and incorporated.