// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Based on the x86 implementation.
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*
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* Copyright (C) 2012 ARM Ltd.
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* Author: Marc Zyngier <marc.zyngier@arm.com>
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*/
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#include <linux/perf_event.h>
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#include <linux/kvm_host.h>
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#include <asm/kvm_emulate.h>
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DEFINE_STATIC_KEY_FALSE(kvm_arm_pmu_available);
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static int kvm_is_in_guest(void)
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{
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return kvm_get_running_vcpu() != NULL;
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}
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static int kvm_is_user_mode(void)
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{
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struct kvm_vcpu *vcpu;
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vcpu = kvm_get_running_vcpu();
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if (vcpu)
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return !vcpu_mode_priv(vcpu);
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return 0;
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}
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static unsigned long kvm_get_guest_ip(void)
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{
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struct kvm_vcpu *vcpu;
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vcpu = kvm_get_running_vcpu();
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if (vcpu)
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return *vcpu_pc(vcpu);
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return 0;
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}
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static struct perf_guest_info_callbacks kvm_guest_cbs = {
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.is_in_guest = kvm_is_in_guest,
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.is_user_mode = kvm_is_user_mode,
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.get_guest_ip = kvm_get_guest_ip,
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};
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int kvm_perf_init(void)
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{
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/*
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* Check if HW_PERF_EVENTS are supported by checking the number of
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* hardware performance counters. This could ensure the presence of
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* a physical PMU and CONFIG_PERF_EVENT is selected.
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*/
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if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0
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&& !is_protected_kvm_enabled())
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static_branch_enable(&kvm_arm_pmu_available);
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return perf_register_guest_info_callbacks(&kvm_guest_cbs);
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}
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int kvm_perf_teardown(void)
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{
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return perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
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}
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