[PATCH v4 10/12] KVM: x86/cpuid: Add X86_FEATURE_PERFMON_V2 as a scattered flag

Like Xu
2023-02-14T05:09:22Z

From: Like Xu <likexu@tencent.com>

Considering that the core kernel may also want to know this flag, to avoid
confusion this needs to be a scattered flag rather than a pure KVM flag so
that KVM can redirect it to the hardware-defined bit position, which is the
role of __feature_translate() and KVM_X86_FEATURE_PERFMON_V2.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Like Xu <likexu@tencent.com>
---
arch/x86/kvm/reverse_cpuid.h | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h
index 4945456fd646..333e28b0a13c 100644
--- a/arch/x86/kvm/reverse_cpuid.h
+++ b/arch/x86/kvm/reverse_cpuid.h
@@ -15,6 +15,7 @@ enum kvm_only_cpuid_leafs {
CPUID_12_EAX = NCAPINTS,
CPUID_7_1_EDX,
CPUID_8000_0007_EDX,
+ CPUID_8000_0022_EAX,
NR_KVM_CPU_CAPS,

NKVMCAPINTS = NR_KVM_CPU_CAPS - NCAPINTS,
@@ -47,6 +48,9 @@ enum kvm_only_cpuid_leafs {
/* CPUID level 0x80000007 (EDX). */
#define KVM_X86_FEATURE_CONSTANT_TSC KVM_X86_FEATURE(CPUID_8000_0007_EDX, 8)

+/* CPUID level 0x80000022 (EAX) */
+#define KVM_X86_FEATURE_PERFMON_V2 KVM_X86_FEATURE(CPUID_8000_0022_EAX, 0)
+
struct cpuid_reg {
u32 function;
u32 index;
@@ -73,6 +77,7 @@ static const struct cpuid_reg reverse_cpuid[] = {
[CPUID_8000_001F_EAX] = {0x8000001f, 0, CPUID_EAX},
[CPUID_7_1_EDX] = { 7, 1, CPUID_EDX},
[CPUID_8000_0007_EDX] = {0x80000007, 0, CPUID_EDX},
+ [CPUID_8000_0022_EAX] = {0x80000022, 0, CPUID_EAX},
};

/*
@@ -107,6 +112,8 @@ static __always_inline u32 __feature_translate(int x86_feature)
return KVM_X86_FEATURE_SGX_EDECCSSA;
else if (x86_feature == X86_FEATURE_CONSTANT_TSC)
return KVM_X86_FEATURE_CONSTANT_TSC;
+ else if (x86_feature == X86_FEATURE_PERFMON_V2)
+ return KVM_X86_FEATURE_PERFMON_V2;

return x86_feature;
}
--
2.39.1