diff mbox series

[v2,7/8] x86: KVM: Advertise AVX-NE-CONVERT CPUID to user space

Message ID 20221103025030.78371-8-jiaxi.chen@linux.intel.com
State New
Headers
Series x86: KVM: Advertise CPUID of new Intel platform instructions to user space |

Commit Message

Jiaxi Chen Nov. 3, 2022, 2:50 a.m. UTC 
  AVX-NE-CONVERT is a new set of instructions which can convert low
precision floating point like BF16/FP16 to high precision floating point
FP32, and can also convert FP32 elements to BF16. This instruction
allows the platform to have improved AI capabilities and better
compatibility.

The bit definition:
CPUID.(EAX=7,ECX=1):EDX[bit 5]

This CPUID is exposed to user space. Besides, there is no other VMX
control for this instruction.

Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
---
 arch/x86/kvm/cpuid.c         | 3 ++-
 arch/x86/kvm/reverse_cpuid.h | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 06dacf71ff9c..47ac2a502d91 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -662,7 +662,8 @@  void kvm_set_cpu_caps(void)
 	);
 
 	kvm_cpu_cap_init_scattered(CPUID_7_1_EDX,
-		F(AVX_VNNI_INT8));
+		F(AVX_VNNI_INT8) | F(AVX_NE_CONVERT)
+	);
 
 	kvm_cpu_cap_mask(CPUID_D_1_EAX,
 		F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | F(XSAVES) | f_xfd
diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h
index 819b4e0b13a3..b8addd85b062 100644
--- a/arch/x86/kvm/reverse_cpuid.h
+++ b/arch/x86/kvm/reverse_cpuid.h
@@ -35,6 +35,7 @@  enum kvm_only_cpuid_leafs {
 
 /* Intel-defined sub-features, CPUID level 0x00000007:1 (EDX) */
 #define X86_FEATURE_AVX_VNNI_INT8       KVM_X86_FEATURE(CPUID_7_1_EDX, 4)
+#define X86_FEATURE_AVX_NE_CONVERT      KVM_X86_FEATURE(CPUID_7_1_EDX, 5)
 
 struct cpuid_reg {
 	u32 function;