From: Nicolin Chen nicolinc@nvidia.com Sent: Saturday, October 26, 2024 7:50 AM
Following the previous vIOMMU series, this adds another vDEVICE structure, representing the association from an iommufd_device to an iommufd_viommu. This gives the whole architecture a new "v" layer:
| iommufd (with vIOMMU/vDEVICE) | | _____________ _____________ | | | | | | | | |----------------| vIOMMU |<---| vDEVICE |<------| | | | | | |_____________| | | | | ______ | | _____________ ___|____ | | | | | | | | | | | | | | | IOAS |<---|(HWPT_PAGING)|<---| HWPT_NESTED |<--| DEVICE | | | | |______| |_____________| |_____________| |________| |
|______|________|______________|__________________|_____________ __|_____| | | | | | ______v_____ | ______v_____ ______v_____ ___v__ | struct | | PFN | (paging) | | (nested) | |struct| |iommu_device| |------>|iommu_domain|<----|iommu_domain|<---- |device| |____________| storage|____________| |____________| |______|
This vDEVICE object is used to collect and store all vIOMMU-related device information/attributes in a VM. As an initial series for vDEVICE, add only the virt_id to the vDEVICE, which is a vIOMMU specific device ID in a VM: e.g. vSID of ARM SMMUv3, vDeviceID of AMD IOMMU, and vID of Intel VT-d
s/vID/vRID/ for VT-d
to a Context Table. This virt_id helps IOMMU drivers to link the vID to a pID of the device against the physical IOMMU instance. This is essential for a vIOMMU-based invalidation, where the request contains a device's vID for a device cache flush, e.g. ATC invalidation.
probably connect this to vCMDQ passthrough? otherwise for sw-based invalidation the userspace can always replace vID with pID before submitting the request.
Therefore, with this vDEVICE object, support a vIOMMU-based invalidation, by reusing IOMMUFD_CMD_HWPT_INVALIDATE for a vIOMMU object to flush cache with a given driver data.
As for the implementation of the series, add driver support in ARM SMMUv3 for a real world use case.
This series is on Github: https://github.com/nicolinc/iommufd/commits/iommufd_viommu_p2-v5
For testing, try this "with-rmr" branch: https://github.com/nicolinc/iommufd/commits/iommufd_viommu_p2-v5- with-rmr Paring QEMU branch for testing: https://github.com/nicolinc/qemu/commits/wip/for_iommufd_viommu_p2- v5
Changelog v5
- Dropped driver-allocated vDEVICE support
- Changed vdev_to_dev helper to iommufd_viommu_find_dev
v4 https://lore.kernel.org/all/cover.1729555967.git.nicolinc@nvidia.com/
- Added missing brackets in switch-case
- Fixed the unreleased idev refcount issue
- Reworked the iommufd_vdevice_alloc allocator
- Dropped support for IOMMU_VIOMMU_TYPE_DEFAULT
- Added missing TEST_LENGTH and fail_nth coverages
- Added a verification to the driver-allocated vDEVICE object
- Added an iommufd_vdevice_abort for a missing mutex protection
- Added a u64 structure arm_vsmmu_invalidation_cmd for user command conversion
v3 https://lore.kernel.org/all/cover.1728491532.git.nicolinc@nvidia.com/
- Added Jason's Reviewed-by
- Split this invalidation part out of the part-1 series
- Repurposed VDEV_ID ioctl to a wider vDEVICE structure and ioctl
- Reduced viommu_api functions by allowing drivers to access viommu and vdevice structure directly
- Dropped vdevs_rwsem by using xa_lock instead
- Dropped arm_smmu_cache_invalidate_user
v2 https://lore.kernel.org/all/cover.1724776335.git.nicolinc@nvidia.com/
- Limited vdev_id to one per idev
- Added a rw_sem to protect the vdev_id list
- Reworked driver-level APIs with proper lockings
- Added a new viommu_api file for IOMMUFD_DRIVER config
- Dropped useless iommu_dev point from the viommu structure
- Added missing index numnbers to new types in the uAPI header
- Dropped IOMMU_VIOMMU_INVALIDATE uAPI; Instead, reuse the HWPT
one
- Reworked mock_viommu_cache_invalidate() using the new iommu helper
- Reordered details of set/unset_vdev_id handlers for proper lockings
v1 https://lore.kernel.org/all/cover.1723061377.git.nicolinc@nvidia.com/
Thanks! Nicolin
Jason Gunthorpe (2): iommu: Add iommu_copy_struct_from_full_user_array helper iommu/arm-smmu-v3: Allow ATS for IOMMU_DOMAIN_NESTED
Nicolin Chen (11): iommufd/viommu: Add IOMMUFD_OBJ_VDEVICE and IOMMU_VDEVICE_ALLOC ioctl iommufd/selftest: Add IOMMU_VDEVICE_ALLOC test coverage iommu/viommu: Add cache_invalidate to iommufd_viommu_ops iommufd/hw_pagetable: Enforce invalidation op on vIOMMU-based hwpt_nested iommufd: Allow hwpt_id to carry viommu_id for IOMMU_HWPT_INVALIDATE iommufd/viommu: Add iommufd_viommu_find_dev helper iommufd/selftest: Add mock_viommu_cache_invalidate iommufd/selftest: Add IOMMU_TEST_OP_DEV_CHECK_CACHE test command iommufd/selftest: Add vIOMMU coverage for IOMMU_HWPT_INVALIDATE ioctl Documentation: userspace-api: iommufd: Update vDEVICE iommu/arm-smmu-v3: Add arm_vsmmu_cache_invalidate
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 9 +- drivers/iommu/iommufd/iommufd_private.h | 20 ++ drivers/iommu/iommufd/iommufd_test.h | 30 +++ include/linux/iommu.h | 48 ++++- include/linux/iommufd.h | 21 ++ include/uapi/linux/iommufd.h | 61 +++++- tools/testing/selftests/iommu/iommufd_utils.h | 83 +++++++ .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 161 +++++++++++++- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 32 ++- drivers/iommu/iommufd/device.c | 11 + drivers/iommu/iommufd/driver.c | 13 ++ drivers/iommu/iommufd/hw_pagetable.c | 36 +++- drivers/iommu/iommufd/main.c | 7 + drivers/iommu/iommufd/selftest.c | 98 ++++++++- drivers/iommu/iommufd/viommu.c | 101 +++++++++ tools/testing/selftests/iommu/iommufd.c | 204 +++++++++++++++++- .../selftests/iommu/iommufd_fail_nth.c | 4 + Documentation/userspace-api/iommufd.rst | 41 +++- 18 files changed, 942 insertions(+), 38 deletions(-)
-- 2.43.0