linux-kernel - [RFC PATCH 27/41] KVM: x86/pmu: Clear PERF

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Date: Fri, 26 Jan 2024 16:54:30 +0800
From: Xiong Zhang <xiong.y.zhang@...ux.intel.com>
To: seanjc@...gle.com,
	pbonzini@...hat.com,
	peterz@...radead.org,
	mizhang@...gle.com,
	kan.liang@...el.com,
	zhenyuw@...ux.intel.com,
	dapeng1.mi@...ux.intel.com,
	jmattson@...gle.com
Cc: kvm@...r.kernel.org,
	linux-perf-users@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	zhiyuan.lv@...el.com,
	eranian@...gle.com,
	irogers@...gle.com,
	samantha.alt@...el.com,
	like.xu.linux@...il.com,
	chao.gao@...el.com,
	xiong.y.zhang@...ux.intel.com
Subject: [RFC PATCH 27/41] KVM: x86/pmu: Clear PERF_METRICS MSR for guest

From: Dapeng Mi <dapeng1.mi@...ux.intel.com>

Since perf topdown metrics feature is not supported yet, clear
PERF_METRICS MSR for guest.

Signed-off-by: Dapeng Mi <dapeng1.mi@...ux.intel.com>
---
 arch/x86/kvm/vmx/pmu_intel.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 4b4da7f17895..ad0434646a29 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -916,6 +916,10 @@ static void intel_restore_pmu_context(struct kvm_vcpu *vcpu)
 	 */
 	for (i = pmu->nr_arch_fixed_counters; i < kvm_pmu_cap.num_counters_fixed; i++)
 		wrmsrl(MSR_CORE_PERF_FIXED_CTR0 + i, 0);
+
+	/* Clear PERF_METRICS MSR since guest topdown metrics is not supported yet. */
+	if (kvm_caps.host_perf_cap & PMU_CAP_PERF_METRICS)
+		wrmsrl(MSR_PERF_METRICS, 0);
 }
 
 struct kvm_pmu_ops intel_pmu_ops __initdata = {
-- 
2.34.1