include/wrapper/kvm-x86.h

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   2  *
   3  * wrapper/kvm-x86.h
   4  *
   5  * Copyright (C) 2022 Michael Jeanson <mjeanson@efficios.com>
   6  */
   7
   8 #ifndef _LTTNG_WRAPPER_KVM_X86_H
   9 #define _LTTNG_WRAPPER_KVM_X86_H
  10
  11 #include <linux/kvm_host.h>
  12 #include <lttng/kernel-version.h>
  13
  14 #if LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,18,0)
  15
  16 #ifdef CONFIG_KALLSYMS_ALL
  17 #include <linux/kallsyms.h>
  18 #include <wrapper/kallsyms.h>
  19
  20 static struct kvm_x86_ops *kvm_x86_ops_sym;
  21
  22 static inline
  23 void lttng_kvm_x86_get_exit_info(
  24                 struct kvm_vcpu *vcpu, u32 *reason,
  25                 u64 *info1, u64 *info2,
  26                 u32 *exit_int_info, u32 *exit_int_info_err_code)
  27 {
  28         if (!kvm_x86_ops_sym)
  29                 kvm_x86_ops_sym =
  30                         (void *) kallsyms_lookup_dataptr("kvm_x86_ops");
  31
  32         if (kvm_x86_ops_sym) {
  33                 kvm_x86_ops_sym->get_exit_info(vcpu, reason, info1, info2,
  34                                 exit_int_info, exit_int_info_err_code);
  35         } else {
  36                 printk_once(KERN_WARNING "LTTng: kvm_x86_ops symbol lookup failed.\n");
  37         }
  38 }
  39
  40 static inline
  41 u64 lttng_kvm_x86_get_segment_base(struct kvm_vcpu *vcpu, int seg)
  42 {
  43         if (!kvm_x86_ops_sym)
  44                 kvm_x86_ops_sym =
  45                         (void *) kallsyms_lookup_dataptr("kvm_x86_ops");
  46
  47         if (kvm_x86_ops_sym) {
  48                 return kvm_x86_ops_sym->get_segment_base(vcpu, seg);
  49         } else {
  50                 printk_once(KERN_WARNING "LTTng: kvm_x86_ops symbol lookup failed.\n");
  51                 return 0;
  52         }
  53 }
  54
  55 /*
  56  * Canary function to check for 'kvm_x86_ops' at compile time.
  57  *
  58  * From 'arch/x86/include/asm/kvm_host.h':
  59  *
  60  *   extern struct kvm_x86_ops kvm_x86_ops;;
  61  */
  62 static inline
  63 unsigned int __canary__kvm_x86_ops(void)
  64 {
  65         return kvm_x86_ops.vm_size;
  66 }
  67
  68 #endif /* CONFIG_KALLSYMS_ALL */
  69
  70 #endif
  71
  72 #endif /* _LTTNG_WRAPPER_KVM_X86_H */