The dma-iommu needs to find the correct domain for MSI mapping. With an IOMMU_DOMAIN_NESTED, the mapping resides in its parent paging domain.
Add a get_msi_mapping_domain op for drivers to return paging domains.
Add an iommufd selftest coverage for that, by doing a loopback test.
Add arm_smmu_get_msi_mapping_domain in the SMMUv3 driver so its nesting feature could work with MSI correctly.
This is based on top of the reserved-IOVA change: https://lore.kernel.org/all/20240802053458.2754673-1-nicolinc@nvidia.com/ And Jason's SMMUv3 nesting series: https://lore.kernel.org/all/0-v1-54e734311a7f+14f72-smmuv3_nesting_jgg@nvidi...
This series is on Github: https://github.com/nicolinc/iommufd/commits/iommufd_nesting_sw_msi/
[changelog] v3: * Refined PATCH-2 commit message * Added domain->ops check in PATCH-2 * Added PATCH-4 to implement in SMMUv3 driver v2: https://lore.kernel.org/all/cover.1722644866.git.nicolinc@nvidia.com/ * Resent with a proper bug fix.
Thanks Nicolin
Nicolin Chen (3): iommufd: Reorder include files iommufd/selftest: Add coverage for IOMMU_RESV_SW_MSI iommu/arm-smmu-v3: Implement arm_smmu_get_msi_mapping_domain
Robin Murphy (1): iommu/dma: Support MSIs through nested domains
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 10 ++ drivers/iommu/dma-iommu.c | 18 +++- drivers/iommu/iommufd/device.c | 4 +- drivers/iommu/iommufd/fault.c | 4 +- drivers/iommu/iommufd/io_pagetable.c | 8 +- drivers/iommu/iommufd/io_pagetable.h | 2 +- drivers/iommu/iommufd/ioas.c | 2 +- drivers/iommu/iommufd/iommufd_private.h | 9 +- drivers/iommu/iommufd/iommufd_test.h | 6 +- drivers/iommu/iommufd/iova_bitmap.c | 2 +- drivers/iommu/iommufd/main.c | 8 +- drivers/iommu/iommufd/pages.c | 10 +- drivers/iommu/iommufd/selftest.c | 92 ++++++++++++++++++- include/linux/iommu.h | 4 + include/linux/iommufd.h | 4 +- include/uapi/linux/iommufd.h | 2 +- tools/testing/selftests/iommu/iommufd_utils.h | 9 ++ 17 files changed, 160 insertions(+), 34 deletions(-)