linux-kernel - [PATCH] KVM: x86/pmu: Update pmu->pebs_enable_mask with actual counter

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Date:   Thu, 26 May 2022 16:57:23 +0800
From:   Like Xu <like.xu.linux@...il.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Yanfei Xu <yanfei.xu@...el.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] KVM: x86/pmu: Update pmu->pebs_enable_mask with actual counter_mask

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

The blamed commit is posted before the PEBS merge in, but is applied after
the latter is merged in. Fix dependency of pebs_enable_mask on
a new reusable counter_mask instead of zero-initialized global_ctrl.

Fixes: 94e05293f839 ("KVM: x86/pmu: Don't overwrite the pmu->global_ctrl when refreshing")
Signed-off-by: Like Xu <likexu@...cent.com>
---
 arch/x86/kvm/vmx/pmu_intel.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index ddf837130d1f..72bbcb3f9f8a 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -621,6 +621,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 	struct kvm_cpuid_entry2 *entry;
 	union cpuid10_eax eax;
 	union cpuid10_edx edx;
+	u64 counter_mask;
 	int i;
 
 	pmu->nr_arch_gp_counters = 0;
@@ -672,8 +673,9 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 
 	for (i = 0; i < pmu->nr_arch_fixed_counters; i++)
 		pmu->fixed_ctr_ctrl_mask &= ~(0xbull << (i * 4));
-	pmu->global_ctrl_mask = ~(((1ull << pmu->nr_arch_gp_counters) - 1) |
+	counter_mask = ~(((1ull << pmu->nr_arch_gp_counters) - 1) |
 		(((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED));
+	pmu->global_ctrl_mask = counter_mask;
 	pmu->global_ovf_ctrl_mask = pmu->global_ctrl_mask
 			& ~(MSR_CORE_PERF_GLOBAL_OVF_CTRL_OVF_BUF |
 			    MSR_CORE_PERF_GLOBAL_OVF_CTRL_COND_CHGD);
@@ -713,7 +715,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 	if (vcpu->arch.perf_capabilities & PERF_CAP_PEBS_FORMAT) {
 		vcpu->arch.ia32_misc_enable_msr &= ~MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL;
 		if (vcpu->arch.perf_capabilities & PERF_CAP_PEBS_BASELINE) {
-			pmu->pebs_enable_mask = ~pmu->global_ctrl;
+			pmu->pebs_enable_mask = counter_mask;
 			pmu->reserved_bits &= ~ICL_EVENTSEL_ADAPTIVE;
 			for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
 				pmu->fixed_ctr_ctrl_mask &=
-- 
2.36.1