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-rw-r--r--virt/kvm/arm/pmu.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
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+++ b/virt/kvm/arm/pmu.c
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+/*
+ * Copyright (C) 2015 Linaro Ltd.
+ * Author: Shannon Zhao <shannon.zhao@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/cpu.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/perf_event.h>
+#include <asm/kvm_emulate.h>
+#include <kvm/arm_pmu.h>
+
+/**
+ * kvm_pmu_get_counter_value - get PMU counter value
+ * @vcpu: The vcpu pointer
+ * @select_idx: The counter index
+ */
+u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
+{
+ u64 counter, reg, enabled, running;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc = &pmu->pmc[select_idx];
+
+ reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
+ ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx;
+ counter = vcpu_sys_reg(vcpu, reg);
+
+ /* The real counter value is equal to the value of counter register plus
+ * the value perf event counts.
+ */
+ if (pmc->perf_event)
+ counter += perf_event_read_value(pmc->perf_event, &enabled,
+ &running);
+
+ return counter & pmc->bitmask;
+}
+
+/**
+ * kvm_pmu_set_counter_value - set PMU counter value
+ * @vcpu: The vcpu pointer
+ * @select_idx: The counter index
+ * @val: The counter value
+ */
+void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val)
+{
+ u64 reg;
+
+ reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
+ ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx;
+ vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx);
+}