linux-kernel - [PATCH 1/3] KVM: x86/pmu: Ignore pmu->global_ctrl check if vPMU doesn't support global

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Message-Id: <20220509102204.62389-1-likexu@tencent.com>
Date:   Mon,  9 May 2022 18:22:02 +0800
From:   Like Xu <like.xu.linux@...il.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Jim Mattson <jmattson@...gle.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 1/3] KVM: x86/pmu: Ignore pmu->global_ctrl check if vPMU doesn't support global_ctrl

From: Like Xu <likexu@...cent.com>

MSR_CORE_PERF_GLOBAL_CTRL is introduced as part of Architecture PMU V2,
as indicated by Intel SDM 19.2.2 and the intel_is_valid_msr() function.

So in the absence of global_ctrl support, all PMCs are enabled as AMD does.

Signed-off-by: Like Xu <likexu@...cent.com>
---
 arch/x86/kvm/vmx/pmu_intel.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index b82b6709d7a8..cff03baf8921 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -98,6 +98,9 @@ static bool intel_pmc_is_enabled(struct kvm_pmc *pmc)
 {
 	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 
+	if (pmu->version < 2)
+		return true;
+
 	return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
 }
 
-- 
2.36.1