Hi,

This is v4 of optimizing the shadow s2 mmu unmapping during MMU
notifiers. The general theme stays the same, but various
improvements/fixes are added. Thanks for all the feedback. Please see
below for the changes.

* Changes from v3 [1]:

  - Rebased on to the latest kvmarm/fixes.

  - Removed commit "KVM: arm64: Move shadow_pt_debugfs_dentry to reduce
    holes in kvm_s2_mmu" because the current shadow ptdump code is found
    to be buggy and the proposed fix removes shadow_pt_debugfs_dentry [2].

  - Rename some variables to improve readability e.g. ipa ->
    canonical_ipa, fault_ipa -> nested_ipa.

  - Skip reverse map optimization when !mmu->nested_stage2_enabled,
    and just unmap the canonical IPA range during MMU notifiers.

  - Change comment above the code that checks whether an identical
    reverse map already exists in kvm_record_nested_revmap() from saying
    it could be a permission update to saying another parallel stage-2
    fault could have inserted an identical reverse map. This is because
    permission update won't trigger kvm_record_nested_revmap().

  - Add helpers for checking maple tree entry flags VALID_ENTRY and
    UNKNOWN_IPA, also warn if both are set at the same time.

  - Test canonical IPA alignment with the mapping size during reverse
    map insertion.

  - Move clean up of kvm_unmap_gfn_range() to its own patch.

  - Avoid naming variables with "*dir*", as it can be misunderstood to
    be related to directories.

  - Use mas_find() instead of mas_find_range() as mas_find_range()
    returns every range including empty/NULL ranges, for our use case
    we only want to iterate over non-NULL ranges.

  - Added a trace point to track when the reverse map maple tree becomes
    "broken" i.e. maple tree insertion failure.

Thanks!

[1]: https://lore.kernel.org/kvmarm/20260510145338.322962-1-weilin.chang@arm.com/
[2]: https://lore.kernel.org/kvmarm/20260630121005.1130996-1-weilin.chang@arm.com/

Wei-Lin Chang (6):
  KVM: arm64: Use a variable for the canonical GPA in kvm_s2_fault_map()
  KVM: arm64: nv: Avoid full shadow s2 unmap
  KVM: arm64: nv: Add nested revmap broken tracepoint
  KVM: arm64: Refactor kvm_unmap_gfn_range() with common variables
  KVM: arm64: nv: Remove reverse map entries during TLBI handling
  KVM: arm64: nv: Create nested IPA direct map to speed up reverse map
    removal

 arch/arm64/include/asm/kvm_host.h   |   9 +
 arch/arm64/include/asm/kvm_nested.h |   6 +
 arch/arm64/kvm/mmu.c                |  42 +++--
 arch/arm64/kvm/nested.c             | 280 +++++++++++++++++++++++++++-
 arch/arm64/kvm/sys_regs.c           |   3 +
 arch/arm64/kvm/trace_arm.h          |  27 +++
 6 files changed, 349 insertions(+), 18 deletions(-)

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2.43.0