Commit 59cc99f6 authored by Like Xu's avatar Like Xu Committed by Paolo Bonzini
Browse files

KVM: x86/cpuid: Refactor host/guest CPU model consistency check 



For the same purpose, the leagcy intel_pmu_lbr_is_compatible() can be
renamed for reuse by more callers, and remove the comment about LBR
use case can be deleted by the way.

Signed-off-by: default avatarLike Xu <like.xu@linux.intel.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-17-likexu@tencent.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 968635ab

arch/x86/kvm/cpuid.h

+5 −0
Original line number Diff line number Diff line
@@ -145,6 +145,11 @@ static inline int guest_cpuid_model(struct kvm_vcpu *vcpu) 
	return x86_model(best->eax);

}



static inline bool cpuid_model_is_consistent(struct kvm_vcpu *vcpu)

{

	return boot_cpu_data.x86_model == guest_cpuid_model(vcpu);

}



static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu)

{

	struct kvm_cpuid_entry2 *best;

arch/x86/kvm/vmx/pmu_intel.c

+1 −11
Original line number Diff line number Diff line
@@ -167,16 +167,6 @@ static inline struct kvm_pmc *get_fw_gp_pmc(struct kvm_pmu *pmu, u32 msr) 
	return get_gp_pmc(pmu, msr, MSR_IA32_PMC0);

}



bool intel_pmu_lbr_is_compatible(struct kvm_vcpu *vcpu)

{

	/*

	 * As a first step, a guest could only enable LBR feature if its

	 * cpu model is the same as the host because the LBR registers

	 * would be pass-through to the guest and they're model specific.

	 */

	return boot_cpu_data.x86_model == guest_cpuid_model(vcpu);

}



bool intel_pmu_lbr_is_enabled(struct kvm_vcpu *vcpu)

{

	struct x86_pmu_lbr *lbr = vcpu_to_lbr_records(vcpu);
@@ -595,7 +585,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu) 
	nested_vmx_pmu_refresh(vcpu,

			       intel_is_valid_msr(vcpu, MSR_CORE_PERF_GLOBAL_CTRL));



	if (intel_pmu_lbr_is_compatible(vcpu))

	if (cpuid_model_is_consistent(vcpu))

		x86_perf_get_lbr(&lbr_desc->records);

	else

		lbr_desc->records.nr = 0;

arch/x86/kvm/vmx/vmx.c

+1 −1
Original line number Diff line number Diff line
@@ -2242,7 +2242,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 
			if ((data & PMU_CAP_LBR_FMT) !=

			    (vmx_get_perf_capabilities() & PMU_CAP_LBR_FMT))

				return 1;

			if (!intel_pmu_lbr_is_compatible(vcpu))

			if (!cpuid_model_is_consistent(vcpu))

				return 1;

		}

		ret = kvm_set_msr_common(vcpu, msr_info);

arch/x86/kvm/vmx/vmx.h

+0 −1
Original line number Diff line number Diff line
@@ -95,7 +95,6 @@ union vmx_exit_reason { 
#define vcpu_to_lbr_records(vcpu) (&to_vmx(vcpu)->lbr_desc.records)



void intel_pmu_cross_mapped_check(struct kvm_pmu *pmu);

bool intel_pmu_lbr_is_compatible(struct kvm_vcpu *vcpu);

bool intel_pmu_lbr_is_enabled(struct kvm_vcpu *vcpu);



int intel_pmu_create_guest_lbr_event(struct kvm_vcpu *vcpu);