[PATCH 2/2] KVM: Expose AVX_VNNI instruction to guset

Yang Zhong
2020-12-16T02:56:59Z

Expose AVX (VEX-encoded) versions of the Vector Neural Network
Instructions to guest.

The bit definition:
CPUID.(EAX=7,ECX=1):EAX[bit 4] AVX_VNNI

The following instructions are available when this feature is
present in the guest.
1. VPDPBUS: Multiply and Add Unsigned and Signed Bytes
2. VPDPBUSDS: Multiply and Add Unsigned and Signed Bytes with Saturation
3. VPDPWSSD: Multiply and Add Signed Word Integers
4. VPDPWSSDS: Multiply and Add Signed Integers with Saturation

This instruction is currently documented in the latest "extensions"
manual (ISE). It will appear in the "main" manual (SDM) in the future.

Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
---
arch/x86/kvm/cpuid.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 83637a2ff605..4229b67f0a8d 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -433,7 +433,7 @@ void kvm_set_cpu_caps(void)
kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL_SSBD);

kvm_cpu_cap_mask(CPUID_7_1_EAX,
- F(AVX512_BF16)
+ F(AVX_VNNI) | F(AVX512_BF16)
);

kvm_cpu_cap_mask(CPUID_D_1_EAX,
--
2.29.2.334.gfaefdd61ec