arch/arm/kvm/perf.c

   1 /*
   2  * Based on the x86 implementation.
   3  *
   4  * Copyright (C) 2012 ARM Ltd.
   5  * Author: Marc Zyngier <marc.zyngier@arm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/perf_event.h>
  21 #include <linux/kvm_host.h>
  22
  23 #include <asm/kvm_emulate.h>
  24
  25 static int kvm_is_in_guest(void)
  26 {
  27         return kvm_arm_get_running_vcpu() != NULL;
  28 }
  29
  30 static int kvm_is_user_mode(void)
  31 {
  32         struct kvm_vcpu *vcpu;
  33
  34         vcpu = kvm_arm_get_running_vcpu();
  35
  36         if (vcpu)
  37                 return !vcpu_mode_priv(vcpu);
  38
  39         return 0;
  40 }
  41
  42 static unsigned long kvm_get_guest_ip(void)
  43 {
  44         struct kvm_vcpu *vcpu;
  45
  46         vcpu = kvm_arm_get_running_vcpu();
  47
  48         if (vcpu)
  49                 return *vcpu_pc(vcpu);
  50
  51         return 0;
  52 }
  53
  54 static struct perf_guest_info_callbacks kvm_guest_cbs = {
  55         .is_in_guest    = kvm_is_in_guest,
  56         .is_user_mode   = kvm_is_user_mode,
  57         .get_guest_ip   = kvm_get_guest_ip,
  58 };
  59
  60 int kvm_perf_init(void)
  61 {
  62         return perf_register_guest_info_callbacks(&kvm_guest_cbs);
  63 }
  64
  65 int kvm_perf_teardown(void)
  66 {
  67         return perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
  68 }