From: Tao Su Date: Wed, 2 Aug 2023 02:29:54 +0000 (+0800) Subject: KVM: x86: Advertise AMX-COMPLEX CPUID to userspace X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=99b668545356115e11a6cca519361c8cfd02569e;p=linux.git KVM: x86: Advertise AMX-COMPLEX CPUID to userspace Latest Intel platform GraniteRapids-D introduces AMX-COMPLEX, which adds two instructions to perform matrix multiplication of two tiles containing complex elements and accumulate the results into a packed single precision tile. AMX-COMPLEX is enumerated via CPUID.(EAX=7,ECX=1):EDX[bit 8] Advertise AMX_COMPLEX if it's supported in hardware. There are no VMX controls for the feature, i.e. the instructions can't be interecepted, and KVM advertises base AMX in CPUID if AMX is supported in hardware, even if KVM doesn't advertise AMX as being supported in XCR0, e.g. because the process didn't opt-in to allocating tile data. Signed-off-by: Tao Su Reviewed-by: Xiaoyao Li Link: https://lore.kernel.org/r/20230802022954.193843-1-tao1.su@linux.intel.com [sean: tweak last paragraph of changelog] Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index ad6566636c22d..5a88affb2e1a4 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -647,7 +647,8 @@ void kvm_set_cpu_caps(void) ); kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX, - F(AVX_VNNI_INT8) | F(AVX_NE_CONVERT) | F(PREFETCHITI) + F(AVX_VNNI_INT8) | F(AVX_NE_CONVERT) | F(PREFETCHITI) | + F(AMX_COMPLEX) ); kvm_cpu_cap_mask(CPUID_D_1_EAX, diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h index 56cbdb24400ae..b816506783755 100644 --- a/arch/x86/kvm/reverse_cpuid.h +++ b/arch/x86/kvm/reverse_cpuid.h @@ -43,6 +43,7 @@ enum kvm_only_cpuid_leafs { /* Intel-defined sub-features, CPUID level 0x00000007:1 (EDX) */ #define X86_FEATURE_AVX_VNNI_INT8 KVM_X86_FEATURE(CPUID_7_1_EDX, 4) #define X86_FEATURE_AVX_NE_CONVERT KVM_X86_FEATURE(CPUID_7_1_EDX, 5) +#define X86_FEATURE_AMX_COMPLEX KVM_X86_FEATURE(CPUID_7_1_EDX, 8) #define X86_FEATURE_PREFETCHITI KVM_X86_FEATURE(CPUID_7_1_EDX, 14) /* CPUID level 0x80000007 (EDX). */