Commit fe8d76c1 authored by Like Xu's avatar Like Xu Committed by Sean Christopherson
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KVM: x86/cpuid: Add a KVM-only leaf to redirect AMD PerfMonV2 flag 



Add a KVM-only leaf for AMD's PerfMonV2 to redirect the kernel's scattered
version to its architectural location, e.g. so that KVM can query guest
support via guest_cpuid_has().

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarLike Xu <likexu@tencent.com>
[sean: massage changelog]
Link: https://lore.kernel.org/r/20230603011058.1038821-11-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 1c2bf8a6

arch/x86/kvm/reverse_cpuid.h

+7 −0
Original line number Diff line number Diff line
@@ -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;
@@ -74,6 +78,7 @@ static const struct cpuid_reg reverse_cpuid[] = { 
	[CPUID_7_1_EDX]       = {         7, 1, CPUID_EDX},

	[CPUID_8000_0007_EDX] = {0x80000007, 0, CPUID_EDX},

	[CPUID_8000_0021_EAX] = {0x80000021, 0, CPUID_EAX},

	[CPUID_8000_0022_EAX] = {0x80000022, 0, CPUID_EAX},

};



/*
@@ -108,6 +113,8 @@ 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;

}