1 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c
new file mode 100644
index 000000000000..5414b134f99a
--- /dev/null
+++ b/arch/arm64/kvm/pmu.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Arm Limited
+ * Author: Andrew Murray <Andrew.Murray@arm.com>
+ */
+#include <linux/kvm_host.h>
+#include <linux/perf_event.h>
+
+/*
+ * Given the exclude_{host,guest} attributes, determine if we are going
+ * to need to switch counters at guest entry/exit.
+ */
+static bool kvm_pmu_switch_needed(struct perf_event_attr *attr)
+{
+	/* Only switch if attributes are different */
+	return (attr->exclude_host != attr->exclude_guest);
+}
+
+/*
+ * Add events to track that we may want to switch at guest entry/exit
+ * time.
+ */
+void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr)
+{
+	struct kvm_host_data *ctx = this_cpu_ptr(&kvm_host_data);
+
+	if (!kvm_pmu_switch_needed(attr))
+		return;
+
+	if (!attr->exclude_host)
+		ctx->pmu_events.events_host |= set;
+	if (!attr->exclude_guest)
+		ctx->pmu_events.events_guest |= set;
+}
+
+/*
+ * Stop tracking events
+ */
+void kvm_clr_pmu_events(u32 clr)
+{
+	struct kvm_host_data *ctx = this_cpu_ptr(&kvm_host_data);
+
+	ctx->pmu_events.events_host &= ~clr;
+	ctx->pmu_events.events_guest &= ~clr;
+}