[PATCH v7 0/3] Add Intel VT-d nested translation (part 2/2)

Yi Liu
2023-11-17T13:18:18Z

This is the second part to add Intel VT-d nested translation based on IOMMUFD
nesting infrastructure. As the iommufd nesting infrastructure series [1],
iommu core supports new ops to invalidate the cache after the modifictions
in stage-1 page table. So far, the cache invalidation data is vendor specific,
the data_type (IOMMU_HWPT_DATA_VTD_S1) defined for the vendor specific HWPT
allocation is reused in the cache invalidation path. User should provide the
correct data_type that suit with the type used in HWPT allocation.

IOMMU_HWPT_INVALIDATE iotcl returns an error in @out_driver_error_code. However
Intel VT-d does not define error code so far, so it's not easy to pre-define it
in iommufd neither. As a result, this field should just be ignored on VT-d platform.

Complete code can be found in [2], corresponding QEMU could can be found in [3].

[1] https://lore.kernel.org/linux-iommu/20231117130717.19875-1-yi.l.liu@intel.com/#t
[2] https://github.com/yiliu1765/iommufd/tree/iommufd_nesting
[3] https://github.com/yiliu1765/qemu/tree/zhenzhong/wip/iommufd_nesting_rfcv1

Change log:

v7:
- No much change, just rebase on top of 6.7-rc1

v6: https://lore.kernel.org/linux-iommu/20231020093719.18725-1-yi.l.liu@intel.com/
- Address comments from Kevin
- Split the VT-d nesting series into two parts (Jason)

v5: https://lore.kernel.org/linux-iommu/20230921075431.125239-1-yi.l.liu@intel.com/
- Add Kevin's r-b for patch 2, 3 ,5 8, 10
- Drop enforce_cache_coherency callback from the nested type domain ops (Kevin)
- Remove duplicate agaw check in patch 04 (Kevin)
- Remove duplicate domain_update_iommu_cap() in patch 06 (Kevin)
- Check parent's force_snooping to set pgsnp in the pasid entry (Kevin)
- uapi data structure check (Kevin)
- Simplify the errata handling as user can allocate nested parent domain

v4: https://lore.kernel.org/linux-iommu/20230724111335.107427-1-yi.l.liu@intel.com/
- Remove ascii art tables (Jason)
- Drop EMT (Tina, Jason)
- Drop MTS and related definitions (Kevin)
- Rename macro IOMMU_VTD_PGTBL_ to IOMMU_VTD_S1_ (Kevin)
- Rename struct iommu_hwpt_intel_vtd_ to iommu_hwpt_vtd_ (Kevin)
- Rename struct iommu_hwpt_intel_vtd to iommu_hwpt_vtd_s1 (Kevin)
- Put the vendor specific hwpt alloc data structure before enuma iommu_hwpt_type (Kevin)
- Do not trim the higher page levels of S2 domain in nested domain attachment as the
S2 domain may have been used independently. (Kevin)
- Remove the first-stage pgd check against the maximum address of s2_domain as hw
can check it anyhow. It makes sense to check every pfns used in the stage-1 page
table. But it cannot make it. So just leave it to hw. (Kevin)
- Split the iotlb flush part into an order of uapi, helper and callback implementation (Kevin)
- Change the policy of VT-d nesting errata, disallow RO mapping once a domain is used
as parent domain of a nested domain. This removes the nested_users counting. (Kevin)
- Minor fix for "make htmldocs"

v3: https://lore.kernel.org/linux-iommu/20230511145110.27707-1-yi.l.liu@intel.com/
- Further split the patches into an order of adding helpers for nested
domain, iotlb flush, nested domain attachment and nested domain allocation
callback, then report the hw_info to userspace.
- Add batch support in cache invalidation from userspace
- Disallow nested translation usage if RO mappings exists in stage-2 domain
due to errata on readonly mappings on Sapphire Rapids platform.

v2: https://lore.kernel.org/linux-iommu/20230309082207.612346-1-yi.l.liu@intel.com/
- The iommufd infrastructure is split to be separate series.

v1: https://lore.kernel.org/linux-iommu/20230209043153.14964-1-yi.l.liu@intel.com/

Regards,
Yi Liu

Yi Liu (3):
iommufd: Add data structure for Intel VT-d stage-1 cache invalidation
iommu/vt-d: Make iotlb flush helpers to be extern
iommu/vt-d: Add iotlb flush for nested domain

drivers/iommu/intel/iommu.c | 10 +++----
drivers/iommu/intel/iommu.h | 6 ++++
drivers/iommu/intel/nested.c | 54 ++++++++++++++++++++++++++++++++++++
include/uapi/linux/iommufd.h | 36 ++++++++++++++++++++++++
4 files changed, 101 insertions(+), 5 deletions(-)

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2.34.1