From: Liu, Yi L yi.l.liu@intel.com Sent: Monday, July 24, 2023 7:04 PM
From: Lu Baolu baolu.lu@linux.intel.com
Introduce a new domain type for a user I/O page table, which is nested on top of another user space address represented by a UNMANAGED domain. The mappings of a nested domain are managed by user space software, therefore it's unnecessary to have map/unmap callbacks. But the updates of the PTEs in the nested domain page table must be propagated to the caches on both IOMMU (IOTLB) and devices (DevTLB).
The nested domain is allocated by the domain_alloc_user op, and attached to the device through the existing iommu_attach_device/group() interfaces.
A new domain op, named cache_invalidate_user is added for the userspace to flush the hardware caches for a nested domain through iommufd. No wrapper for it, as it's only supposed to be used by iommufd.
Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Co-developed-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Yi Liu yi.l.liu@intel.com
Reviewed-by: Kevin Tian kevin.tian@intel.com