[PATCH v5 04/13] iommufd/viommu: Add IOMMU_VIOMMU_ALLOC ioctl

[Tian, Kevin]

> From: Nicolin Chen <nicolinc at nvidia.com>
> Sent: Saturday, October 26, 2024 7:50 AM
> 
> Add a new ioctl for user space to do a vIOMMU allocation. It must be based
> on a nesting parent HWPT, so take its refcount.
> 
> IOMMU driver wanting to support vIOMMUs must define its
> IOMMU_VIOMMU_TYPE_
> in the uAPI header and implement a viommu_alloc op in its iommu_ops.
> 
> Reviewed-by: Jason Gunthorpe <jgg at nvidia.com>
> Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>

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