[PATCH] x86/cpufeatures: Make AVX512_BMM depend on AVX512F
From: Jim Mattson
Date: Wed Jul 15 2026 - 18:40:43 EST
Add an explicit dependency between X86_FEATURE_AVX512_BMM and
X86_FEATURE_AVX512F in the CPUID dependency table.
AVX512 Bit Matrix Multiply (BMM) instructions operate on vector registers
and require AVX512 Foundation support. Declaring this dependency ensures
that if AVX512F is disabled (e.g. via clearcpuid or host capabilities),
AVX512_BMM will be automatically cleared as well.
Fixes: de0bfdc7137d ("KVM: x86: Advertise AVX512 Bit Matrix Multiply (BMM) to userspace")
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
---
arch/x86/kernel/cpu/cpuid-deps.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index 99801e844b30..e9fdf944633b 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -75,6 +75,7 @@ static const struct cpuid_dep cpuid_deps[] = {
{ X86_FEATURE_SDCIAE, X86_FEATURE_CAT_L3 },
{ X86_FEATURE_AVX512_BF16, X86_FEATURE_AVX512VL },
{ X86_FEATURE_AVX512_FP16, X86_FEATURE_AVX512BW },
+ { X86_FEATURE_AVX512_BMM, X86_FEATURE_AVX512F },
{ X86_FEATURE_ENQCMD, X86_FEATURE_XSAVES },
{ X86_FEATURE_PER_THREAD_MBA, X86_FEATURE_MBA },
{ X86_FEATURE_SGX_LC, X86_FEATURE_SGX },
--
2.55.0.141.g00534a21ce-goog