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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240126085444.324918-28-xiong.y.zhang@linux.intel.com>
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