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