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From: Yang Zhong <yang.zhong@intel.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org
Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
	hpa@zytor.com, tony.luck@intel.com, pbonzini@redhat.com,
	seanjc@google.com, vkuznets@redhat.com, wanpengli@tencent.com,
	jmattson@google.com, joro@8bytes.org, kyung.min.park@intel.com,
	yang.zhong@intel.com
Subject: [PATCH 1/2] Enumerate AVX Vector Neural Network instructions
Date: Tue,  5 Jan 2021 08:49:08 +0800	[thread overview]
Message-ID: <20210105004909.42000-2-yang.zhong@intel.com> (raw)
In-Reply-To: <20210105004909.42000-1-yang.zhong@intel.com>

From: Kyung Min Park <kyung.min.park@intel.com>

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 <kyung.min.park@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
---
 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 f5ef2d5b9231..d10d9962bd9b 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -293,6 +293,7 @@
 #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 */
-- 
2.29.2.334.gfaefdd61ec


  reply	other threads:[~2021-01-05  1:42 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-05  0:49 [PATCH 0/2] Enumerate and expose AVX_VNNI feature Yang Zhong
2021-01-05  0:49 ` Yang Zhong [this message]
2021-01-05 11:47   ` [PATCH 1/2] Enumerate AVX Vector Neural Network instructions Paolo Bonzini
2021-01-05 12:14     ` Borislav Petkov
2021-01-12  2:13       ` Yang Zhong
2021-01-13 12:54         ` Paolo Bonzini
2021-01-05  0:49 ` [PATCH 2/2] KVM: Expose AVX_VNNI instruction to guset Yang Zhong
2021-01-21 15:02 ` [PATCH 0/2] Enumerate and expose AVX_VNNI feature Paolo Bonzini
2021-01-22  6:43   ` Yang Zhong
  -- strict thread matches above, loose matches on Subject: below --
2020-12-16  2:01 Yang Zhong
2020-12-16  2:01 ` [PATCH 1/2] Enumerate AVX Vector Neural Network instructions Yang Zhong

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