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| author | Jiaxi Chen <jiaxi.chen@linux.intel.com> | 2022-11-25 13:58:42 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-11-28 19:33:28 +0100 |
| commit | 5e85c4ebf206e50c58e82ca44c15e2be2bac6923 (patch) | |
| tree | eea7adac6a5aa734baa8ae629ec425e14c08f0ce /arch/x86/include/asm/cpufeatures.h | |
| parent | x86: KVM: Advertise AMX-FP16 CPUID to user space (diff) | |
| download | linux-5e85c4ebf206e50c58e82ca44c15e2be2bac6923.tar.xz linux-5e85c4ebf206e50c58e82ca44c15e2be2bac6923.zip | |
x86: KVM: Advertise AVX-IFMA CPUID to user space
AVX-IFMA is a new instruction in the latest Intel platform Sierra
Forest. This instruction packed multiplies unsigned 52-bit integers and
adds the low/high 52-bit products to Qword Accumulators.
The bit definition:
CPUID.(EAX=7,ECX=1):EAX[bit 23]
AVX-IFMA is on an expected-dense CPUID leaf and some other bits on this
leaf have kernel usages. Given that, define this feature bit like
X86_FEATURE_<name> in kernel. Considering AVX-IFMA itself has no truly
kernel usages and /proc/cpuinfo has too much unreadable flags, hide this
one in /proc/cpuinfo.
Advertise AVX-IFMA to KVM userspace. This is safe because there are no
new VMX controls or additional host enabling required for guests to use
this feature.
Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Message-Id: <20221125125845.1182922-6-jiaxi.chen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/cpufeatures.h')
| -rw-r--r-- | arch/x86/include/asm/cpufeatures.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 20059dc33d24..1419c4e04d45 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -310,6 +310,7 @@ #define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instructions */ #define X86_FEATURE_CMPCCXADD (12*32+ 7) /* "" CMPccXADD instructions */ #define X86_FEATURE_AMX_FP16 (12*32+21) /* "" AMX fp16 Support */ +#define X86_FEATURE_AVX_IFMA (12*32+23) /* "" Support for VPMADD52[H,L]UQ */ /* AMD-defined CPU features, CPUID level 0x80000008 (EBX), word 13 */ #define X86_FEATURE_CLZERO (13*32+ 0) /* CLZERO instruction */ |