linux-kernel - [PATCH] KVM: SVM: Emulate PERF_CNTR_GLOBAL_STATUS

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20250711172746.1579423-1-seanjc@google.com>
Date: Fri, 11 Jul 2025 10:27:46 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Sandipan Das <sandipan.das@....com>
Subject: [PATCH] KVM: SVM: Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2

Emulate PERF_CNTR_GLOBAL_STATUS_SET when PerfMonV2 is enumerated to the
guest, as the MSR is supposed to exist in all AMD v2 PMUs.

Fixes: 4a2771895ca6 ("KVM: x86/svm/pmu: Add AMD PerfMonV2 support")
Cc: stable@...r.kernel.org
Cc: Sandipan Das <sandipan.das@....com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/include/asm/msr-index.h | 1 +
 arch/x86/kvm/pmu.c               | 5 +++++
 arch/x86/kvm/svm/pmu.c           | 1 +
 arch/x86/kvm/x86.c               | 2 ++
 4 files changed, 9 insertions(+)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index fa878b136eba..ea5366b733c3 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -732,6 +732,7 @@
 #define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS	0xc0000300
 #define MSR_AMD64_PERF_CNTR_GLOBAL_CTL		0xc0000301
 #define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR	0xc0000302
+#define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET	0xc0000303
 
 /* AMD Last Branch Record MSRs */
 #define MSR_AMD64_LBR_SELECT			0xc000010e
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 75e9cfc689f8..a84fb3d28885 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -650,6 +650,7 @@ int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		msr_info->data = pmu->global_ctrl;
 		break;
 	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR:
+	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET:
 	case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 		msr_info->data = 0;
 		break;
@@ -711,6 +712,10 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		if (!msr_info->host_initiated)
 			pmu->global_status &= ~data;
 		break;
+	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET:
+		if (!msr_info->host_initiated)
+			pmu->global_status |= data & ~pmu->global_status_rsvd;
+		break;
 	default:
 		kvm_pmu_mark_pmc_in_use(vcpu, msr_info->index);
 		return kvm_pmu_call(set_msr)(vcpu, msr_info);
diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c
index 288f7f2a46f2..aa4379e46e96 100644
--- a/arch/x86/kvm/svm/pmu.c
+++ b/arch/x86/kvm/svm/pmu.c
@@ -113,6 +113,7 @@ static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS:
 	case MSR_AMD64_PERF_CNTR_GLOBAL_CTL:
 	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR:
+	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET:
 		return pmu->version > 1;
 	default:
 		if (msr > MSR_F15H_PERF_CTR5 &&
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2806f7104295..15c34fbac22a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -367,6 +367,7 @@ static const u32 msrs_to_save_pmu[] = {
 	MSR_AMD64_PERF_CNTR_GLOBAL_CTL,
 	MSR_AMD64_PERF_CNTR_GLOBAL_STATUS,
 	MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR,
+	MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET,
 };
 
 static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_base) +
@@ -7353,6 +7354,7 @@ static void kvm_probe_msr_to_save(u32 msr_index)
 	case MSR_AMD64_PERF_CNTR_GLOBAL_CTL:
 	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS:
 	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR:
+	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET:
 		if (!kvm_cpu_cap_has(X86_FEATURE_PERFMON_V2))
 			return;
 		break;

base-commit: 6c7ecd725e503bf2ca69ff52c6cc48bb650b1f11
-- 
2.50.0.727.gbf7dc18ff4-goog