Commit 2224fc9e authored Dec 07, 2020 by Cathy Zhang Committed by Paolo Bonzini Dec 11, 2020

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>

parent e1b35da5

arch/x86/kvm/cpuid.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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. */

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