[PATCH v5 30/44] KVM: x86/pmu: Move initialization of valid PMCs bitmask to common x86

Sean Christopherson
2025-08-06T19:58:24Z

Move all initialization of all_valid_pmc_idx to common code, as the logic
is 100% common to Intel and AMD, and KVM heavily relies on Intel and AMD
having the same semantics. E.g. the fact that AMD doesn't support fixed
counters doesn't allow KVM to use all_valid_pmc_idx[63:32] for other
purposes.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/pmu.c | 4 ++++
arch/x86/kvm/svm/pmu.c | 1 -
arch/x86/kvm/vmx/pmu_intel.c | 5 -----
3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index a4fe0e76df79..4246e1d2cfcc 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -932,6 +932,10 @@ void kvm_pmu_refresh(struct kvm_vcpu *vcpu)
if (kvm_vcpu_has_mediated_pmu(vcpu))
kvm_pmu_call(write_global_ctrl)(pmu->global_ctrl);
}
+
+ bitmap_set(pmu->all_valid_pmc_idx, 0, pmu->nr_arch_gp_counters);
+ bitmap_set(pmu->all_valid_pmc_idx, KVM_FIXED_PMC_BASE_IDX,
+ pmu->nr_arch_fixed_counters);
}

void kvm_pmu_init(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c
index b777c3743304..9ffd44a5d474 100644
--- a/arch/x86/kvm/svm/pmu.c
+++ b/arch/x86/kvm/svm/pmu.c
@@ -209,7 +209,6 @@ static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
/* not applicable to AMD; but clean them to prevent any fall out */
pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
pmu->nr_arch_fixed_counters = 0;
- bitmap_set(pmu->all_valid_pmc_idx, 0, pmu->nr_arch_gp_counters);
}

static void amd_pmu_init(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 6352d029298c..1de94a39ca18 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -579,11 +579,6 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
pmu->raw_event_mask |= (HSW_IN_TX|HSW_IN_TX_CHECKPOINTED);
}

- bitmap_set(pmu->all_valid_pmc_idx,
- 0, pmu->nr_arch_gp_counters);
- bitmap_set(pmu->all_valid_pmc_idx,
- INTEL_PMC_MAX_GENERIC, pmu->nr_arch_fixed_counters);
-
perf_capabilities = vcpu_get_perf_capabilities(vcpu);
if (intel_pmu_lbr_is_compatible(vcpu) &&
(perf_capabilities & PERF_CAP_LBR_FMT))
--
2.50.1.565.gc32cd1483b-goog