[v6,0/3] Add Intel VT-d nested translation (part 2/2)

Message

Yi Liu Oct. 20, 2023, 9:37 a.m. UTC

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/[e-mail]/
[2] https://github.com/yiliu1765/iommufd/tree/iommufd_nesting
[3] https://github.com/yiliu1765/qemu/tree/zhenzhong/wip/iommufd_nesting_rfcv1

Change log:

v6:
 - Address comments from Kevin
 - Split the VT-d nesting series into two parts (Jason)

v5: https://lore.kernel.org/linux-iommu/[e-mail]/
 - 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/[e-mail]/
 - 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/[e-mail]/
 - 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/[e-mail]/
 - The iommufd infrastructure is split to be separate series.

v1: https://lore.kernel.org/linux-iommu/[e-mail]/

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(-)