diff mbox series

[14/15] KVM: x86: Add Arch LBR data MSR access interface

Message ID 20220831223438.413090-15-weijiang.yang@intel.com (mailing list archive)
State New, archived
Headers show
Series Introduce Architectural LBR for vPMU | expand

Commit Message

Yang, Weijiang Aug. 31, 2022, 10:34 p.m. UTC 
Arch LBR MSRs are xsave-supported, but they're operated as "independent"
xsave feature by PMU code, i.e., during thread/process context switch,
the MSRs are saved/restored with perf_event_task_sched_{in|out} instead
of generic kernel fpu switch code, i.e.,save_fpregs_to_fpstate() and
restore_fpregs_from_fpstate(). When vcpu guest/host fpu state swap happens,
Arch LBR MSRs are retained so they can be accessed directly.

Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Message-Id: <20220517154100.29983-16-weijiang.yang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/pmu_intel.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index e06de1f29fe7..006969bd00fe 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -414,6 +414,11 @@  static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 			msr_info->data = vmcs_read64(GUEST_IA32_LBR_CTL);
 		}
 		return 0;
+	case MSR_ARCH_LBR_FROM_0 ... MSR_ARCH_LBR_FROM_0 + 31:
+	case MSR_ARCH_LBR_TO_0 ... MSR_ARCH_LBR_TO_0 + 31:
+	case MSR_ARCH_LBR_INFO_0 ... MSR_ARCH_LBR_INFO_0 + 31:
+		rdmsrl(msr_info->index, msr_info->data);
+		return 0;
 	default:
 		if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
 		    (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) {
@@ -528,6 +533,11 @@  static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		    (data & ARCH_LBR_CTL_LBREN))
 			intel_pmu_create_guest_lbr_event(vcpu);
 		return 0;
+	case MSR_ARCH_LBR_FROM_0 ... MSR_ARCH_LBR_FROM_0 + 31:
+	case MSR_ARCH_LBR_TO_0 ... MSR_ARCH_LBR_TO_0 + 31:
+	case MSR_ARCH_LBR_INFO_0 ... MSR_ARCH_LBR_INFO_0 + 31:
+		wrmsrl(msr_info->index, msr_info->data);
+		return 0;
 	default:
 		if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
 		    (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) {