# git rev-parse -q --verify 463f46e114f74465cf8d01b124e7b74ad1ce2afd^{commit}
463f46e114f74465cf8d01b124e7b74ad1ce2afd
already have revision, skipping fetch
# git checkout -q -f -B kisskb 463f46e114f74465cf8d01b124e7b74ad1ce2afd
# git clean -qxdf
# < git log -1
# commit 463f46e114f74465cf8d01b124e7b74ad1ce2afd
# Merge: ff269e2cd5ad b2b67c997bf7
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Wed Nov 1 16:44:56 2023 -1000
# 
#     Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd
#     
#     Pull iommufd updates from Jason Gunthorpe:
#      "This brings three new iommufd capabilities:
#     
#        - Dirty tracking for DMA.
#     
#          AMD/ARM/Intel CPUs can now record if a DMA writes to a page in the
#          IOPTEs within the IO page table. This can be used to generate a
#          record of what memory is being dirtied by DMA activities during a
#          VM migration process. A VMM like qemu will combine the IOMMU dirty
#          bits with the CPU's dirty log to determine what memory to transfer.
#     
#          VFIO already has a DMA dirty tracking framework that requires PCI
#          devices to implement tracking HW internally. The iommufd version
#          provides an alternative that the VMM can select, if available. The
#          two are designed to have very similar APIs.
#     
#        - Userspace controlled attributes for hardware page tables
#          (HWPT/iommu_domain). There are currently a few generic attributes
#          for HWPTs (support dirty tracking, and parent of a nest). This is
#          an entry point for the userspace iommu driver to control the HW in
#          detail.
#     
#        - Nested translation support for HWPTs. This is a 2D translation
#          scheme similar to the CPU where a DMA goes through a first stage to
#          determine an intermediate address which is then translated trough a
#          second stage to a physical address.
#     
#          Like for CPU translation the first stage table would exist in VM
#          controlled memory and the second stage is in the kernel and matches
#          the VM's guest to physical map.
#     
#          As every IOMMU has a unique set of parameter to describe the S1 IO
#          page table and its associated parameters the userspace IOMMU driver
#          has to marshal the information into the correct format.
#     
#          This is 1/3 of the feature, it allows creating the nested
#          translation and binding it to VFIO devices, however the API to
#          support IOTLB and ATC invalidation of the stage 1 io page table,
#          and forwarding of IO faults are still in progress.
#     
#       The series includes AMD and Intel support for dirty tracking. Intel
#       support for nested translation.
#     
#       Along the way are a number of internal items:
#     
#        - New iommu core items: ops->domain_alloc_user(),
#          ops->set_dirty_tracking, ops->read_and_clear_dirty(),
#          IOMMU_DOMAIN_NESTED, and iommu_copy_struct_from_user
#     
#        - UAF fix in iopt_area_split()
#     
#        - Spelling fixes and some test suite improvement"
#     
#     * tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (52 commits)
#       iommufd: Organize the mock domain alloc functions closer to Joerg's tree
#       iommufd/selftest: Fix page-size check in iommufd_test_dirty()
#       iommufd: Add iopt_area_alloc()
#       iommufd: Fix missing update of domains_itree after splitting iopt_area
#       iommu/vt-d: Disallow read-only mappings to nest parent domain
#       iommu/vt-d: Add nested domain allocation
#       iommu/vt-d: Set the nested domain to a device
#       iommu/vt-d: Make domain attach helpers to be extern
#       iommu/vt-d: Add helper to setup pasid nested translation
#       iommu/vt-d: Add helper for nested domain allocation
#       iommu/vt-d: Extend dmar_domain to support nested domain
#       iommufd: Add data structure for Intel VT-d stage-1 domain allocation
#       iommu/vt-d: Enhance capability check for nested parent domain allocation
#       iommufd/selftest: Add coverage for IOMMU_HWPT_ALLOC with nested HWPTs
#       iommufd/selftest: Add nested domain allocation for mock domain
#       iommu: Add iommu_copy_struct_from_user helper
#       iommufd: Add a nested HW pagetable object
#       iommu: Pass in parent domain with user_data to domain_alloc_user op
#       iommufd: Share iommufd_hwpt_alloc with IOMMUFD_OBJ_HWPT_NESTED
#       iommufd: Derive iommufd_hwpt_paging from iommufd_hw_pagetable
#       ...
# < /opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-ld --version
# < git log --format=%s --max-count=1 463f46e114f74465cf8d01b124e7b74ad1ce2afd
# make -s -j 40 ARCH=x86 O=/kisskb/build/linus_x86_64_defconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-  x86_64_defconfig
# < make -s -j 40 ARCH=x86 O=/kisskb/build/linus_x86_64_defconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-  help
# make -s -j 40 ARCH=x86 O=/kisskb/build/linus_x86_64_defconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-  olddefconfig
# make -s -j 40 ARCH=x86 O=/kisskb/build/linus_x86_64_defconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-  
Completed OK
# rm -rf /kisskb/build/linus_x86_64_defconfig_x86_64-gcc8
# Build took: 0:01:35.801287