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KVM: x86: Expose AVX512_FP16 for supported CPUID 

AVX512_FP16 is supported by Intel processors, like Sapphire Rapids.
It could gain better performance for it's faster compared to FP32
if the precision or magnitude requirements are met. It's availability
is indicated by CPUID.(EAX=7,ECX=0):EDX[bit 23].

Expose it in KVM supported CPUID, then guest could make use of it; no
new registers are used, only new instructions.

Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Message-Id: <20201208033441.28207-3-kyung.min.park@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
zero-sugar-mainline-defconfig
Cathy Zhang 2020-12-07 19:34:41 -08:00 committed by Paolo Bonzini
parent e1b35da5e6
commit 2224fc9efb
1 changed files with 1 additions and 1 deletions
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2
arch/x86/kvm/cpuid.c
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@ -419,7 +419,7 @@ void kvm_set_cpu_caps(void)
F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) |
F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM) |
F(SERIALIZE) | F(TSXLDTRK)
F(SERIALIZE) | F(TSXLDTRK) | F(AVX512_FP16)
);
/* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */