Intel: AVX VNNI: x86: Enumerate AVX Vector Neural Network instructions

mainline inclusion
from mainline-5.11
commit b85a0425
category: feature
feature: SPR New instructions
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I596EH
CVE: N/A

Intel-SIG: commit b85a0425 x86: Enumerate AVX Vector Neural Network instructions
Backport for SPR core AVX VNNI support.

----------------------------

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: NKyung Min Park <kyung.min.park@intel.com>
Signed-off-by: NYang Zhong <yang.zhong@intel.com>
Reviewed-by: NTony Luck <tony.luck@intel.com>
Message-Id: <20210105004909.42000-2-yang.zhong@intel.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NLuming Yu <luming.yu@intel.com>

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 */