linux-kernel - [PATCH v5 12/12] KVM/VMX/vPMU: support to report GLOBAL_STATUS_LBRS

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Date:   Thu, 14 Feb 2019 17:06:14 +0800
From:   Wei Wang <wei.w.wang@...el.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        pbonzini@...hat.com, ak@...ux.intel.com, peterz@...radead.org
Cc:     kan.liang@...el.com, mingo@...hat.com, rkrcmar@...hat.com,
        like.xu@...el.com, wei.w.wang@...el.com, jannh@...gle.com,
        arei.gonglei@...wei.com, jmattson@...gle.com
Subject: [PATCH v5 12/12] KVM/VMX/vPMU: support to report GLOBAL_STATUS_LBRS_FROZEN

Arch v4 supports streamlined Freeze_LBR_on_PMI, so we set the
GLOBAL_STATUS_LBRS_FROZEN bit when the guest reads the global
status msr with freezing lbr in use.

Signed-off-by: Wei Wang <wei.w.wang@...el.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Andi Kleen <ak@...ux.intel.com>
---
 arch/x86/kvm/vmx/pmu_intel.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index bf40941..80d3fcf 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -420,6 +420,25 @@ static bool intel_pmu_access_lbr_msr(struct kvm_vcpu *vcpu,
 	return ret;
 }
 
+static void intel_pmu_get_global_status(struct kvm_pmu *pmu,
+					struct msr_data *msr_info)
+{
+	u64 guest_debugctl, freeze_lbr_bits = DEBUGCTLMSR_FREEZE_LBRS_ON_PMI |
+					      DEBUGCTLMSR_LBR;
+
+	if (!pmu->global_status) {
+		msr_info->data = 0;
+		return;
+	}
+
+	msr_info->data = pmu->global_status;
+	if (pmu->version >= 4) {
+		guest_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
+		if ((guest_debugctl & freeze_lbr_bits) == freeze_lbr_bits)
+			msr_info->data |= GLOBAL_STATUS_LBRS_FROZEN;
+	}
+}
+
 static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 {
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
@@ -431,7 +450,7 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		msr_info->data = pmu->fixed_ctr_ctrl;
 		return 0;
 	case MSR_CORE_PERF_GLOBAL_STATUS:
-		msr_info->data = pmu->global_status;
+		intel_pmu_get_global_status(pmu, msr_info);
 		return 0;
 	case MSR_CORE_PERF_GLOBAL_CTRL:
 		msr_info->data = pmu->global_ctrl;
-- 
2.7.4