arch/arm64/kvm/perf.c

   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
  16 static int kvm_is_in_guest(void)
  17 {
  18         return kvm_get_running_vcpu() != NULL;
  19 }
  20
  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
  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
  51 int kvm_perf_init(void)
  52 {
  53         if (kvm_pmu_probe_pmuver() != ID_AA64DFR0_PMUVER_IMP_DEF && !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
  59 int kvm_perf_teardown(void)
  60 {
  61         return perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
  62 }