1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Based on the x86 implementation.
4  *
5  * Copyright (C) 2012 ARM Ltd.
6  * Author: Marc Zyngier <marc.zyngier@arm.com>
7  */
8 
9 #include <linux/perf_event.h>
10 #include <linux/kvm_host.h>
11 
12 #include <asm/kvm_emulate.h>
13 
14 DEFINE_STATIC_KEY_FALSE(kvm_arm_pmu_available);
15 
kvm_is_in_guest(void)16 static int kvm_is_in_guest(void)
17 {
18         return kvm_get_running_vcpu() != NULL;
19 }
20 
kvm_is_user_mode(void)21 static int kvm_is_user_mode(void)
22 {
23 	struct kvm_vcpu *vcpu;
24 
25 	vcpu = kvm_get_running_vcpu();
26 
27 	if (vcpu)
28 		return !vcpu_mode_priv(vcpu);
29 
30 	return 0;
31 }
32 
kvm_get_guest_ip(void)33 static unsigned long kvm_get_guest_ip(void)
34 {
35 	struct kvm_vcpu *vcpu;
36 
37 	vcpu = kvm_get_running_vcpu();
38 
39 	if (vcpu)
40 		return *vcpu_pc(vcpu);
41 
42 	return 0;
43 }
44 
45 static struct perf_guest_info_callbacks kvm_guest_cbs = {
46 	.is_in_guest	= kvm_is_in_guest,
47 	.is_user_mode	= kvm_is_user_mode,
48 	.get_guest_ip	= kvm_get_guest_ip,
49 };
50 
kvm_perf_init(void)51 int kvm_perf_init(void)
52 {
53 	if (kvm_pmu_probe_pmuver() != 0xf && !is_protected_kvm_enabled())
54 		static_branch_enable(&kvm_arm_pmu_available);
55 
56 	return perf_register_guest_info_callbacks(&kvm_guest_cbs);
57 }
58 
kvm_perf_teardown(void)59 int kvm_perf_teardown(void)
60 {
61 	return perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
62 }
63