From: Wanpeng Li <kernellwp@gmail.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>
Subject: [PATCH 2/3] KVM: vPMU: Fill get_msr MSR_CORE_PERF_GLOBAL_OVF_CTRL w/ 0
Date: Fri, 8 Oct 2021 02:57:33 -0700 [thread overview]
Message-ID: <1633687054-18865-2-git-send-email-wanpengli@tencent.com> (raw)
In-Reply-To: <1633687054-18865-1-git-send-email-wanpengli@tencent.com>
From: Wanpeng Li <wanpengli@tencent.com>
SDM section 18.2.3 mentioned that:
"IA32_PERF_GLOBAL_OVF_CTL MSR allows software to clear overflow indicator(s) of
any general-purpose or fixed-function counters via a single WRMSR."
It is R/W mentioned by SDM, we read this msr on bare-metal during perf testing,
the value is always 0 for CLX/SKX boxes on hands. Let's fill get_msr
MSR_CORE_PERF_GLOBAL_OVF_CTRL w/ 0 as hardware behavior.
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
Btw, xen also fills get_msr MSR_CORE_PERF_GLOBAL_OVF_CTRL 0.
arch/x86/kvm/vmx/pmu_intel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 10cc4f65c4ef..47260a8563f9 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -365,7 +365,7 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
msr_info->data = pmu->global_ctrl;
return 0;
case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
- msr_info->data = pmu->global_ovf_ctrl;
+ msr_info->data = 0;
return 0;
default:
if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
--
2.25.1
next prev parent reply other threads:[~2021-10-08 9:58 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-08 9:57 [PATCH 1/3] KVM: emulate: #GP when emulating rdpmc if CR0.PE is 1 Wanpeng Li
2021-10-08 9:57 ` Wanpeng Li [this message]
2021-10-08 11:02 ` [PATCH 2/3] KVM: vPMU: Fill get_msr MSR_CORE_PERF_GLOBAL_OVF_CTRL w/ 0 Like Xu
2021-10-08 11:17 ` Wanpeng Li
2021-10-08 9:57 ` [PATCH 3/3] KVM: LAPIC: Optimize PMI delivering overhead Wanpeng Li
2021-10-08 10:52 ` Vitaly Kuznetsov
2021-10-08 11:06 ` Wanpeng Li
2021-10-08 15:59 ` Sean Christopherson
2021-10-09 9:14 ` Wanpeng Li
2021-10-08 15:20 ` [PATCH 1/3] KVM: emulate: #GP when emulating rdpmc if CR0.PE is 1 Sean Christopherson
2021-10-09 9:09 ` Wanpeng Li
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