KVM: x86/pmu: Extract check_pmu_event_filter() handling both GP and fixed counters

Checking the kvm->arch.pmu_event_filter policy in both gp and fixed
code paths was somewhat redundant, so common parts can be extracted,
which reduces code footprint and improves readability.

Signed-off-by: Like Xu <likexu@tencent.com>
Reviewed-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <20220518132512.37864-3-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 72512a33a04e29a54afd63857fa34a516ea63903..ee6b2895faed16fad2c6dab2774ff559ee90a786 100644 (file)
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -250,14 +250,44 @@ static int cmp_u64(const void *pa, const void *pb)
        return (a > b) - (a < b);
 }
 
+static bool check_pmu_event_filter(struct kvm_pmc *pmc)
+{
+       struct kvm_pmu_event_filter *filter;
+       struct kvm *kvm = pmc->vcpu->kvm;
+       bool allow_event = true;
+       __u64 key;
+       int idx;
+
+       filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
+       if (!filter)
+               goto out;
+
+       if (pmc_is_gp(pmc)) {
+               key = pmc->eventsel & AMD64_RAW_EVENT_MASK_NB;
+               if (bsearch(&key, filter->events, filter->nevents,
+                           sizeof(__u64), cmp_u64))
+                       allow_event = filter->action == KVM_PMU_EVENT_ALLOW;
+               else
+                       allow_event = filter->action == KVM_PMU_EVENT_DENY;
+       } else {
+               idx = pmc->idx - INTEL_PMC_IDX_FIXED;
+               if (filter->action == KVM_PMU_EVENT_DENY &&
+                   test_bit(idx, (ulong *)&filter->fixed_counter_bitmap))
+                       allow_event = false;
+               if (filter->action == KVM_PMU_EVENT_ALLOW &&
+                   !test_bit(idx, (ulong *)&filter->fixed_counter_bitmap))
+                       allow_event = false;
+       }
+
+out:
+       return allow_event;
+}
+
 void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
 {
        u64 config;
        u32 type = PERF_TYPE_RAW;
-       struct kvm *kvm = pmc->vcpu->kvm;
-       struct kvm_pmu_event_filter *filter;
-       struct kvm_pmu *pmu = vcpu_to_pmu(pmc->vcpu);
-       bool allow_event = true;
+       struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 
        if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL)
                printk_once("kvm pmu: pin control bit is ignored\n");
@@ -269,17 +299,7 @@ void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
        if (!(eventsel & ARCH_PERFMON_EVENTSEL_ENABLE) || !pmc_is_enabled(pmc))
                return;
 
-       filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
-       if (filter) {
-               __u64 key = eventsel & AMD64_RAW_EVENT_MASK_NB;
-
-               if (bsearch(&key, filter->events, filter->nevents,
-                           sizeof(__u64), cmp_u64))
-                       allow_event = filter->action == KVM_PMU_EVENT_ALLOW;
-               else
-                       allow_event = filter->action == KVM_PMU_EVENT_DENY;
-       }
-       if (!allow_event)
+       if (!check_pmu_event_filter(pmc))
                return;
 
        if (!(eventsel & (ARCH_PERFMON_EVENTSEL_EDGE |
@@ -312,23 +332,14 @@ void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int idx)
 {
        unsigned en_field = ctrl & 0x3;
        bool pmi = ctrl & 0x8;
-       struct kvm_pmu_event_filter *filter;
-       struct kvm *kvm = pmc->vcpu->kvm;
 
        pmc_pause_counter(pmc);
 
        if (!en_field || !pmc_is_enabled(pmc))
                return;
 
-       filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
-       if (filter) {
-               if (filter->action == KVM_PMU_EVENT_DENY &&
-                   test_bit(idx, (ulong *)&filter->fixed_counter_bitmap))
-                       return;
-               if (filter->action == KVM_PMU_EVENT_ALLOW &&
-                   !test_bit(idx, (ulong *)&filter->fixed_counter_bitmap))
-                       return;
-       }
+       if (!check_pmu_event_filter(pmc))
+               return;
 
        if (pmc->current_config == (u64)ctrl && pmc_resume_counter(pmc))
                return;