Commit 54d60681 authored Oct 25, 2023 by Lu Baolu Committed by Jason Gunthorpe Oct 26, 2023

iommu: Add IOMMU_DOMAIN_NESTED

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 PAGING domain. This
new domain can be allocated by the domain_alloc_user op, and attached to
a device through the existing iommu_attach_device/group() interfaces.

The mappings of a nested domain are managed by user space software, so it
is not necessary to have map/unmap callbacks.

Link: https://lore.kernel.org/r/20231026043938.63898-2-yi.l.liu@intel.com


Signed-off-by: Lu Baolu <baolu.lu@linux.intel.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>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

parent 2ccabf81

include/linux/iommu.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -67,6 +67,9 @@ struct iommu_domain_geometry {

		#define __IOMMU_DOMAIN_SVA (1U << 4) /* Shared process address space */

		#define __IOMMU_DOMAIN_NESTED (1U << 6) /* User-managed address space nested
		on a stage-2 translation */

		#define IOMMU_DOMAIN_ALLOC_FLAGS ~__IOMMU_DOMAIN_DMA_FQ
		/*
		* This are the possible domain-types
		@@ -93,6 +96,7 @@ struct iommu_domain_geometry {
		__IOMMU_DOMAIN_DMA_API \| \
		__IOMMU_DOMAIN_DMA_FQ)
		#define IOMMU_DOMAIN_SVA (__IOMMU_DOMAIN_SVA)
		#define IOMMU_DOMAIN_NESTED (__IOMMU_DOMAIN_NESTED)

		struct iommu_domain {
		unsigned type;