RE: [PATCH v5 06/13] iommufd: Allow pt_id to carry viommu_id for IOMMU_HWPT_ALLOC

From: Nicolin Chen nicolinc@nvidia.com Sent: Saturday, October 26, 2024 7:50 AM

Now a vIOMMU holds a shareable nesting parent HWPT. So, it can act like that nesting parent HWPT to allocate a nested HWPT.

Support that in the IOMMU_HWPT_ALLOC ioctl handler, and update its kdoc.

Also, add an iommufd_hwpt_nested_alloc_for_viommu helper to allocate a

the helper name is not updated.

nested HWPT for a vIOMMU object. Since a vIOMMU object holds the parent hwpt's refcount already, increase the refcount of the vIOMMU only.

Signed-off-by: Nicolin Chen nicolinc@nvidia.com

Reviewed-by: Kevin Tian kevin.tian@intel.com