[PATCH v1 0/4] x86/cpuid: Fix up the CPUID dependency table

[Guixiong Wei]

Several instruction-set features added to cpufeatures.h are missing
their entries in cpuid_deps[], plus there is one duplicate entry.

As a result, clearing a base feature (e.g. AVX via "clearcpuid=",
"noxsave" or the GDS mitigation) does not clear the dependent features,
leaving an inconsistent CPUID state that is also propagated to KVM
guests, without check_cpufeature_deps() warning about it.

Add the missing dependencies following the existing convention
(VEX-encoded/YMM instructions depend on AVX, EVEX-encoded AVX-512
instructions depend on AVX512F) and drop the duplicate. Patch 1 is an
independent, no-functional-change cleanup; patches 2-4 are ordered
oldest-Fixes first.

Guixiong Wei (4):
  x86/cpuid: Remove duplicate XMM3 dependency entry
  x86/cpuid: Add a dependency of AVX-IFMA on AVX
  x86/cpuid: Add dependencies of SHA512, SM3 and SM4 on AVX
  x86/cpuid: Add a dependency of AVX512-BMM on AVX512F

 arch/x86/kernel/cpu/cpuid-deps.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)


base-commit: f5bbbfec59b4e2fb7520a91de3df8a6174325d6a
-- 
2.50.1 (Apple Git-155)