Add an arm64 version of "struct kvm_page_fault" to (hopefully) tidy up
the abort path, and to pave the way for things like KVM Userfault[*] that
want to consume kvm_page_fault in arch-neutral code.

This is essentially one giant nop of code shuffling.

RFC as this is only compile-tested.  I didn't want to spend time testing
until I got feedback on whether or not y'all are amenable to the general idea.

[*] https://lore.kernel.org/all/20250618042424.330664-1-jthoughton@google.com

Sean Christopherson (16):
  KVM: arm64: Drop nested "esr" to eliminate variable shadowing
  KVM: arm64: Get iabt status on-demand
  KVM: arm64: Move SRCU-protected region of kvm_handle_guest_abort() to
    helper
  KVM: arm64: Use guard(srcu) in kvm_handle_guest_abort()
  KVM: arm64: Introduce "struct kvm_page_fault" for tracking abort state
  KVM: arm64: Pass kvm_page_fault pointer to
    transparent_hugepage_adjust()
  KVM: arm64: Pass @fault to fault_supports_stage2_huge_mapping()
  KVM: arm64: Add helper to get permission fault granule from ESR
  KVM: arm64: Track perm fault granule in "struct kvm_page_fault"
  KVM: arm64: Drop local vfio_allow_any_uc, use vm_flags snapshot
  KVM: arm64: Drop local mte_allowed, use vm_flags snapshot
  KVM: arm64: Move VMA-related information into "struct kvm_page_fault"
  KVM: arm64: Stash "mmu_seq" in "struct kvm_page_fault"
  KVM: arm64: Track "forced" information in "struct kvm_page_fault"
  KVM: arm64: Extract mmap_lock-protected code to helper for user mem
    aborts
  KVM: arm64: Don't bother nullifying "vma" in mem abort path

 arch/arm64/include/asm/esr.h         |   6 +
 arch/arm64/include/asm/kvm_emulate.h |   9 -
 arch/arm64/include/asm/kvm_host.h    |  32 ++
 arch/arm64/kvm/mmu.c                 | 514 +++++++++++++--------------
 4 files changed, 282 insertions(+), 279 deletions(-)


base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
-- 
2.51.0.261.g7ce5a0a67e-goog

On Thu, Aug 21, 2025 at 02:00:26PM -0700, Sean Christopherson wrote:
> Add an arm64 version of "struct kvm_page_fault" to (hopefully) tidy up
> the abort path, and to pave the way for things like KVM Userfault[*] that
> want to consume kvm_page_fault in arch-neutral code.
> 
> This is essentially one giant nop of code shuffling.
> 
> RFC as this is only compile-tested.  I didn't want to spend time testing
> until I got feedback on whether or not y'all are amenable to the general idea.

I appreciate the improved scoping around things like mmap lock, so this
seems like a net-win in terms of readability. Just want to clarify the
way this gets consumed from arch-neutral code and actually read in
detail.

Thanks,
Oliver