[PATCH v2 0/2] KVM: arm64: nv: Fix permission checks for S1PTW faults

[Oliver Upton <oupton@kernel.org>]

Small series that papers over arch ambiguity around S1PTW permission
faults.

As kvm_s2_handle_perm_fault() wasn't checking for S1PTW instruction
aborts, it was incorrectly evaluating the execute permissions to decide
where to send the fault.

Fixing that uncovers another issue in that kvm_is_write_fault() assumes
any S1PTW permission fault was due to write. Nested screws this up since
an L1 hypervisor could use write-only permissions at stage-2.

We end up papering over architecture ambiguity by potentially evaluating
*both* read and write permissions for S1PTW, assuming any fault with HA
set to require write permission (in addition to read).

Applies to kvmarm/fixes.

v1: https://lore.kernel.org/kvmarm/20260623211310.1529760-1-oupton@kernel.org/

Oliver Upton (2):
  KVM: arm64: Only consider S1PTW a write fault if HA is set
  KVM: arm64: nv: Treat S1PTW permission faults specially

 arch/arm64/include/asm/kvm_emulate.h | 22 +++++----------
 arch/arm64/include/asm/kvm_nested.h  |  2 ++
 arch/arm64/kvm/at.c                  | 42 +++++++++++++++++++++-------
 arch/arm64/kvm/nested.c              | 20 +++++++++++--
 4 files changed, 58 insertions(+), 28 deletions(-)


base-commit: d098bb75d14fde2f12155f1a95ec0168160867ce
-- 
2.47.3