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From: Zide Chen <zide.chen@intel.com>
To: Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>
Cc: kvm@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
	Jim Mattson <jmattson@google.com>,
	Stephane Eranian <eranian@google.com>,
	linux-kernel@vger.kernel.org, Mingwei Zhang <mizhang@google.com>,
	Zide Chen <zide.chen@intel.com>,
	Das Sandipan <Sandipan.Das@amd.com>,
	Shukla Manali <Manali.Shukla@amd.com>,
	Dapeng Mi <dapeng1.mi@linux.intel.com>,
	Xudong Hao <xudong.hao@intel.com>
Subject: [PATCH v2 13/16] KVM: x86/pmu: Factor out fixed counter control bit calculation
Date: Thu, 27 Aug 2026 15:37:52 -0700	[thread overview]
Message-ID: <20260827223755.143247-14-zide.chen@intel.com> (raw)
In-Reply-To: <20260827223755.143247-1-zide.chen@intel.com>

Rename intel_pmu_enable_fixed_counter_bits() to
intel_pmu_fixed_ctrl_bits() and have it return the computed fixed
counter control mask instead of updating fixed_ctr_ctrl_rsvd directly.

Accumulate the desired fixed counter control bits during PMU setup and
apply them once in intel_pmu_refresh().

Move the helper next to intel_pmu_set_msr() so it can also be reused
there, which will be needed for upcoming ANYTHREAD_DEPRECATION
emulation.

No functional change intended.

Signed-off-by: Zide Chen <zide.chen@intel.com>
---
v2: New patch
---
 arch/x86/kvm/vmx/pmu_intel.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 1ce69e764ae1..c7472778137a 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -421,6 +421,18 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	return 0;
 }
 
+static u64 intel_pmu_fixed_ctrl_bits(struct kvm_pmu *pmu, u64 bits)
+{
+	unsigned long fixed_mask = kvm_fixed_pmc_mask(pmu);
+	u64 fixed_ctrl_bits = 0;
+	int i;
+
+	kvm_for_each_fixed_counter(i, fixed_mask)
+		fixed_ctrl_bits |= intel_fixed_bits_by_idx(i, bits);
+
+	return fixed_ctrl_bits;
+}
+
 static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 {
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
@@ -533,20 +545,12 @@ static __always_inline u64 intel_get_fixed_pmc_eventsel(unsigned int index)
 	return eventsel;
 }
 
-static void intel_pmu_enable_fixed_counter_bits(struct kvm_pmu *pmu, u64 bits)
-{
-	unsigned long fixed_mask = kvm_fixed_pmc_mask(pmu);
-	int i;
-
-	kvm_for_each_fixed_counter(i, fixed_mask)
-		pmu->fixed_ctr_ctrl_rsvd &= ~intel_fixed_bits_by_idx(i, bits);
-}
-
 static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 {
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 	struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu);
 	struct kvm_cpuid_entry2 *entry;
+	u64 fixed_enable_bits = 0;
 	union cpuid10_eax eax;
 	union cpuid10_edx edx;
 	u64 perf_capabilities;
@@ -625,9 +629,8 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 					  kvm_pmu_cap.bit_width_fixed);
 	pmu->counter_bitmask[KVM_PMC_FIXED] = BIT_ULL(edx.split.bit_width_fixed) - 1;
 
-	intel_pmu_enable_fixed_counter_bits(pmu, INTEL_FIXED_0_KERNEL |
-						 INTEL_FIXED_0_USER |
-						 INTEL_FIXED_0_ENABLE_PMI);
+	fixed_enable_bits |= INTEL_FIXED_0_KERNEL | INTEL_FIXED_0_USER |
+			     INTEL_FIXED_0_ENABLE_PMI;
 
 	counter_rsvd = ~(kvm_gp_pmc_mask(pmu) |
 			((u64)kvm_fixed_pmc_mask(pmu) << KVM_FIXED_PMC_BASE_IDX));
@@ -651,11 +654,14 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 			pmu->pebs_enable_rsvd = counter_rsvd;
 			pmu->eventsel_rsvd &= ~ICL_EVENTSEL_ADAPTIVE;
 			pmu->pebs_data_cfg_rsvd = ~0xff00000full;
-			intel_pmu_enable_fixed_counter_bits(pmu, ICL_FIXED_0_ADAPTIVE);
+			fixed_enable_bits |= ICL_FIXED_0_ADAPTIVE;
 		} else {
 			pmu->pebs_enable_rsvd = ~kvm_gp_pmc_mask(pmu);
 		}
 	}
+
+	pmu->fixed_ctr_ctrl_rsvd &=
+		~intel_pmu_fixed_ctrl_bits(pmu, fixed_enable_bits);
 }
 
 static void intel_pmu_init(struct kvm_vcpu *vcpu)
-- 
2.55.0


  parent reply	other threads:[~2026-08-27 22:48 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-27 22:37 [PATCH] KVM: x86/pmu: Add mediated vPMU PerfMon v5 support Zide Chen
2026-08-27 22:37 ` [PATCH v2 01/16] KVM: x86/pmu: Remove redundant Perf Global Status MSR bit definitions Zide Chen
2026-08-27 22:57   ` sashiko-bot
2026-08-28 13:51     ` Chen, Zide
2026-08-27 22:37 ` [PATCH v2 02/16] KVM: x86/pmu: Rename all_valid_pmc_idx to pmc_exists Zide Chen
2026-08-27 22:37 ` [PATCH v2 03/16] KVM: x86/pmu: Rename reserved_bits to eventsel_rsvd in kvm_pmu Zide Chen
2026-08-27 22:37 ` [PATCH v2 04/16] KVM: x86/pmu: Gate BUFFER_OVF reserved bit on guest DS Zide Chen
2026-08-27 22:37 ` [PATCH v2 05/16] KVM: x86/pmu: Add PMC bitmap accessor helpers Zide Chen
2026-08-27 22:37 ` [PATCH v2 06/16] KVM: x86/pmu: Drop nr_arch_{gp,fixed}_counters from kvm_pmu Zide Chen
2026-08-27 22:37 ` [PATCH v2 07/16] KVM: x86/pmu: Expose kvm_host_pmu to vendor modules Zide Chen
2026-08-27 22:37 ` [PATCH v2 08/16] perf/x86: Plumb counter bitmap from x86_pmu to x86_pmu_cap Zide Chen
2026-08-27 22:37 ` [PATCH v2 09/16] KVM: x86/pmu: Switch to bitmask-based KVM PMU capabilities Zide Chen
2026-08-27 22:37 ` [PATCH v2 10/16] perf/x86: Remove num_counters_{gp,fixed} from x86_pmu_capability Zide Chen
2026-08-27 22:37 ` [PATCH v2 11/16] KVM: x86/pmu: Emulate the GLOBAL_STATUS_SET and GLOBAL_INUSE MSRs Zide Chen
2026-08-27 23:05   ` sashiko-bot
2026-08-28 20:22     ` Chen, Zide
2026-08-27 22:37 ` [PATCH v2 12/16] KVM: x86/pmu: Populate CPUID.0AH:ECX fixed-counter bitmap Zide Chen
2026-08-27 22:37 ` Zide Chen [this message]
2026-08-27 22:37 ` [PATCH v2 14/16] KVM: x86/pmu: Ignore AnyThread bit if CPUID.0AH:EDX[15] is set Zide Chen
2026-08-27 22:37 ` [PATCH v2 15/16] KVM: x86/pmu: Advertise PerfMon version 5 on Intel hosts Zide Chen
2026-08-27 22:37 ` [PATCH v2 16/16] KVM: selftests: Support fixed counters bitmap in pmu_counters_test Zide Chen

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