diff mbox series

[v8,3/7] kvm: x86/pmu: prepare the pmu event filter for masked events

Message ID 20221220161236.555143-4-aaronlewis@google.com (mailing list archive)
State New, archived
Headers show
Series Introduce and test masked events | expand

Commit Message

Aaron Lewis Dec. 20, 2022, 4:12 p.m. UTC 
Refactor check_pmu_event_filter() in preparation for masked events.

No functional changes intended

Signed-off-by: Aaron Lewis <aaronlewis@google.com>
---
 arch/x86/kvm/pmu.c | 56 +++++++++++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 23 deletions(-)

Comments

Like Xu Dec. 22, 2022, 6:34 a.m. UTC | #1 
On 21/12/2022 12:12 am, Aaron Lewis wrote:
> +static bool is_fixed_event_allowed(struct kvm_pmu_event_filter *filter, int idx)
> +{
> +	int fixed_idx = idx - INTEL_PMC_IDX_FIXED;
> +
> +	if (filter->action == KVM_PMU_EVENT_DENY &&
> +	    test_bit(fixed_idx, (ulong *)&filter->fixed_counter_bitmap))
> +		return false;
> +	if (filter->action == KVM_PMU_EVENT_ALLOW &&
> +	    !test_bit(fixed_idx, (ulong *)&filter->fixed_counter_bitmap))
> +		return false;
> +
> +	return true;
> +}

Before masked event is introduced, the decision logic for fixed events is not 
yet covered
by existing and new selftests, which affects the review of new changes to this part.

More selftests on fixed_event is appreciated and required.
diff mbox series

Patch

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 51aac749cb5f..b09a43b66dbe 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -261,41 +261,51 @@  static int cmp_u64(const void *pa, const void *pb)
 	return (a > b) - (a < b);
 }
 
+static u64 *find_filter_entry(struct kvm_pmu_event_filter *filter, u64 key)
+{
+	return bsearch(&key, filter->events, filter->nevents,
+		       sizeof(filter->events[0]), cmp_u64);
+}
+
+static bool is_gp_event_allowed(struct kvm_pmu_event_filter *filter, u64 eventsel)
+{
+	if (find_filter_entry(filter, eventsel & (kvm_pmu_ops.EVENTSEL_EVENT |
+						  ARCH_PERFMON_EVENTSEL_UMASK)))
+		return filter->action == KVM_PMU_EVENT_ALLOW;
+
+	return filter->action == KVM_PMU_EVENT_DENY;
+}
+
+static bool is_fixed_event_allowed(struct kvm_pmu_event_filter *filter, int idx)
+{
+	int fixed_idx = idx - INTEL_PMC_IDX_FIXED;
+
+	if (filter->action == KVM_PMU_EVENT_DENY &&
+	    test_bit(fixed_idx, (ulong *)&filter->fixed_counter_bitmap))
+		return false;
+	if (filter->action == KVM_PMU_EVENT_ALLOW &&
+	    !test_bit(fixed_idx, (ulong *)&filter->fixed_counter_bitmap))
+		return false;
+
+	return true;
+}
+
 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;
 
 	if (!static_call(kvm_x86_pmu_hw_event_available)(pmc))
 		return false;
 
 	filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
 	if (!filter)
-		goto out;
+		return true;
 
-	if (pmc_is_gp(pmc)) {
-		key = pmc->eventsel & (kvm_pmu_ops.EVENTSEL_EVENT |
-				       ARCH_PERFMON_EVENTSEL_UMASK);
-		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;
-	}
+	if (pmc_is_gp(pmc))
+		return is_gp_event_allowed(filter, pmc->eventsel);
 
-out:
-	return allow_event;
+	return is_fixed_event_allowed(filter, pmc->idx);
 }
 
 static void reprogram_counter(struct kvm_pmc *pmc)