From: Cathy Zhang Date: Tue, 8 Dec 2020 03:34:41 +0000 (-0800) Subject: KVM: x86: Expose AVX512_FP16 for supported CPUID X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2224fc9efb2d6593fbfb57287e39ba4958b188ba;p=linux.git 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 Signed-off-by: Kyung Min Park Acked-by: Dave Hansen Reviewed-by: Tony Luck Message-Id: <20201208033441.28207-3-kyung.min.park@intel.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 5d352cc204cec..a22a3108b5f0f 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -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. */