[PATCH v6 01/10] iommu: Add IOMMU_DOMAIN_NESTED

Yi Liu
2023-10-24T15:09:36Z

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 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.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
include/linux/iommu.h | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 1d42bdb37cbc..becfc8b725de 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -67,6 +67,9 @@ struct iommu_domain_geometry {

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

+#define __IOMMU_DOMAIN_NESTED (1U << 5) /* 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;
--
2.34.1