From b85a0425d8056f3bd8d0a94ecdddf2a39d32a801 Mon Sep 17 00:00:00 2001 From: Kyung Min Park Date: Tue, 5 Jan 2021 08:49:08 +0800 Subject: [PATCH] Enumerate AVX Vector Neural Network instructions Add AVX version of the Vector Neural Network (VNNI) Instructions. A processor supports AVX VNNI instructions if CPUID.0x07.0x1:EAX[4] is present. The following instructions are available when this feature is present. 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 The only in-kernel usage of this is kvm passthrough. The CPU feature flag is shown as "avx_vnni" in /proc/cpuinfo. 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: Kyung Min Park Signed-off-by: Yang Zhong Reviewed-by: Tony Luck Message-Id: <20210105004909.42000-2-yang.zhong@intel.com> Acked-by: Borislav Petkov Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/cpufeatures.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 84b8878..bc33e31 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -294,6 +294,7 @@ #define X86_FEATURE_PER_THREAD_MBA (11*32+ 7) /* "" Per-thread Memory Bandwidth Allocation */ /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */ +#define X86_FEATURE_AVX_VNNI (12*32+ 4) /* AVX VNNI instructions */ #define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instructions */ /* AMD-defined CPU features, CPUID level 0x80000008 (EBX), word 13 */ -- 2.7.4