0012-fix-KVM-x86-Unexport-kvm_x86_ops-v5.18.patch

   1 From 45240b53fb037012a86613150fd5dc7e151fb7d1 Mon Sep 17 00:00:00 2001
   2 From: Michael Jeanson <mjeanson@efficios.com>
   3 Date: Mon, 4 Apr 2022 16:28:26 -0400
   4 Subject: [PATCH 12/13] fix: KVM: x86: Unexport kvm_x86_ops (v5.18)
   5
   6 See upstream commit :
   7
   8   commit dfc4e6ca041135217c07ebcd102b6694cea22856
   9   Author: Sean Christopherson <seanjc@google.com>
  10   Date:   Fri Jan 28 00:51:56 2022 +0000
  11
  12     KVM: x86: Unexport kvm_x86_ops
  13
  14     Drop the export of kvm_x86_ops now it is no longer referenced by SVM or
  15     VMX.  Disallowing access to kvm_x86_ops is very desirable as it prevents
  16     vendor code from incorrectly modifying hooks after they have been set by
  17     kvm_arch_hardware_setup(), and more importantly after each function's
  18     associated static_call key has been updated.
  19
  20     No functional change intended.
  21
  22 Change-Id: Icee959a984570f95ab9b71354225b5aeecea7da0
  23 Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
  24 Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  25 ---
  26  .../events/arch/x86/kvm/trace.h               | 47 +++++++++++-
  27  include/wrapper/kvm-x86.h                     | 72 +++++++++++++++++++
  28  2 files changed, 117 insertions(+), 2 deletions(-)
  29  create mode 100644 include/wrapper/kvm-x86.h
  30
  31 diff --git a/include/instrumentation/events/arch/x86/kvm/trace.h b/include/instrumentation/events/arch/x86/kvm/trace.h
  32 index 42e5b94d..0d6c4e33 100644
  33 --- a/include/instrumentation/events/arch/x86/kvm/trace.h
  34 +++ b/include/instrumentation/events/arch/x86/kvm/trace.h
  35 @@ -9,6 +9,7 @@
  36  #include <asm/clocksource.h>
  37  #endif
  38  #include <lttng/kernel-version.h>
  39 +#include <wrapper/kvm-x86.h>
  40  #include <../arch/x86/kvm/lapic.h>
  41  #include <../arch/x86/kvm/kvm_cache_regs.h>
  42
  43 @@ -115,7 +116,40 @@ LTTNG_TRACEPOINT_EVENT_MAP(kvm_apic, kvm_x86_apic,
  44  /*
  45   * Tracepoint for kvm guest exit:
  46   */
  47 -#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,16,0))
  48 +#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,18,0))
  49 +LTTNG_TRACEPOINT_EVENT_CODE_MAP(kvm_exit, kvm_x86_exit,
  50 +       TP_PROTO(struct kvm_vcpu *vcpu, u32 isa),
  51 +       TP_ARGS(vcpu, isa),
  52 +
  53 +       TP_locvar(
  54 +               u32 exit_reason;
  55 +               u64 info1, info2;
  56 +               u32 intr_info, error_code;
  57 +       ),
  58 +
  59 +       TP_code_pre(
  60 +               lttng_kvm_x86_get_exit_info(vcpu,
  61 +                               &tp_locvar->exit_reason,
  62 +                               &tp_locvar->info1,
  63 +                               &tp_locvar->info2,
  64 +                               &tp_locvar->intr_info,
  65 +                               &tp_locvar->error_code);
  66 +       ),
  67 +
  68 +       TP_FIELDS(
  69 +               ctf_integer(unsigned int, exit_reason, tp_locvar->exit_reason)
  70 +               ctf_integer(unsigned long, guest_rip, kvm_rip_read(vcpu))
  71 +               ctf_integer(u32, isa, isa)
  72 +               ctf_integer(u64, info1, tp_locvar->info1)
  73 +               ctf_integer(u64, info2, tp_locvar->info2)
  74 +               ctf_integer(u32, intr_info, tp_locvar->intr_info)
  75 +               ctf_integer(u32, error_code, tp_locvar->error_code)
  76 +               ctf_integer(unsigned int, vcpu_id, vcpu->vcpu_id)
  77 +       ),
  78 +
  79 +       TP_code_post()
  80 +)
  81 +#elif (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,16,0))
  82  LTTNG_TRACEPOINT_EVENT_CODE_MAP(kvm_exit, kvm_x86_exit,
  83         TP_PROTO(struct kvm_vcpu *vcpu, u32 isa),
  84         TP_ARGS(vcpu, isa),
  85 @@ -535,7 +569,7 @@ LTTNG_TRACEPOINT_EVENT_MAP(kvm_emulate_insn, kvm_x86_emulate_insn,
  86                                 vcpu->arch.emulate_ctxt.fetch.data)
  87                 ctf_array(__u8, insn, vcpu->arch.emulate_ctxt.fetch.data, 15)
  88                 ctf_integer(__u8, flags, kei_decode_mode(vcpu->arch.emulate_ctxt.mode))
  89 -#else
  90 +#elif (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(5,18,0))
  91                 ctf_integer(__u64, rip, vcpu->arch.emulate_ctxt->_eip -
  92                                 (vcpu->arch.emulate_ctxt->fetch.ptr -
  93                                         vcpu->arch.emulate_ctxt->fetch.data))
  94 @@ -544,6 +578,15 @@ LTTNG_TRACEPOINT_EVENT_MAP(kvm_emulate_insn, kvm_x86_emulate_insn,
  95                                 vcpu->arch.emulate_ctxt->fetch.data)
  96                 ctf_array(__u8, insn, vcpu->arch.emulate_ctxt->fetch.data, 15)
  97                 ctf_integer(__u8, flags, kei_decode_mode(vcpu->arch.emulate_ctxt->mode))
  98 +#else
  99 +               ctf_integer(__u64, rip, vcpu->arch.emulate_ctxt->_eip -
 100 +                               (vcpu->arch.emulate_ctxt->fetch.ptr -
 101 +                                       vcpu->arch.emulate_ctxt->fetch.data))
 102 +               ctf_integer(__u32, csbase, lttng_kvm_x86_get_segment_base(vcpu, VCPU_SREG_CS))
 103 +               ctf_integer(__u8, len, vcpu->arch.emulate_ctxt->fetch.ptr -
 104 +                               vcpu->arch.emulate_ctxt->fetch.data)
 105 +               ctf_array(__u8, insn, vcpu->arch.emulate_ctxt->fetch.data, 15)
 106 +               ctf_integer(__u8, flags, kei_decode_mode(vcpu->arch.emulate_ctxt->mode))
 107  #endif
 108                 ctf_integer(__u8, failed, failed)
 109         )
 110 diff --git a/include/wrapper/kvm-x86.h b/include/wrapper/kvm-x86.h
 111 new file mode 100644
 112 index 00000000..2007aebd
 113 --- /dev/null
 114 +++ b/include/wrapper/kvm-x86.h
 115 @@ -0,0 +1,72 @@
 116 +/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 117 + *
 118 + * wrapper/kvm-x86.h
 119 + *
 120 + * Copyright (C) 2022 Michael Jeanson <mjeanson@efficios.com>
 121 + */
 122 +
 123 +#ifndef _LTTNG_WRAPPER_KVM_X86_H
 124 +#define _LTTNG_WRAPPER_KVM_X86_H
 125 +
 126 +#include <linux/kvm_host.h>
 127 +#include <lttng/kernel-version.h>
 128 +
 129 +#if LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,18,0)
 130 +
 131 +#ifdef CONFIG_KALLSYMS_ALL
 132 +#include <linux/kallsyms.h>
 133 +#include <wrapper/kallsyms.h>
 134 +
 135 +static struct kvm_x86_ops *kvm_x86_ops_sym;
 136 +
 137 +static inline
 138 +void lttng_kvm_x86_get_exit_info(
 139 +               struct kvm_vcpu *vcpu, u32 *reason,
 140 +               u64 *info1, u64 *info2,
 141 +               u32 *exit_int_info, u32 *exit_int_info_err_code)
 142 +{
 143 +       if (!kvm_x86_ops_sym)
 144 +               kvm_x86_ops_sym =
 145 +                       (void *) kallsyms_lookup_dataptr("kvm_x86_ops");
 146 +
 147 +       if (kvm_x86_ops_sym) {
 148 +               kvm_x86_ops_sym->get_exit_info(vcpu, reason, info1, info2,
 149 +                               exit_int_info, exit_int_info_err_code);
 150 +       } else {
 151 +               printk_once(KERN_WARNING "LTTng: kvm_x86_ops symbol lookup failed.\n");
 152 +       }
 153 +}
 154 +
 155 +static inline
 156 +u64 lttng_kvm_x86_get_segment_base(struct kvm_vcpu *vcpu, int seg)
 157 +{
 158 +       if (!kvm_x86_ops_sym)
 159 +               kvm_x86_ops_sym =
 160 +                       (void *) kallsyms_lookup_dataptr("kvm_x86_ops");
 161 +
 162 +       if (kvm_x86_ops_sym) {
 163 +               return kvm_x86_ops_sym->get_segment_base(vcpu, seg);
 164 +       } else {
 165 +               printk_once(KERN_WARNING "LTTng: kvm_x86_ops symbol lookup failed.\n");
 166 +               return 0;
 167 +       }
 168 +}
 169 +
 170 +/*
 171 + * Canary function to check for 'kvm_x86_ops' at compile time.
 172 + *
 173 + * From 'arch/x86/include/asm/kvm_host.h':
 174 + *
 175 + *   extern struct kvm_x86_ops kvm_x86_ops;;
 176 + */
 177 +static inline
 178 +unsigned int __canary__kvm_x86_ops(void)
 179 +{
 180 +       return kvm_x86_ops.vm_size;
 181 +}
 182 +
 183 +#endif /* CONFIG_KALLSYMS_ALL */
 184 +
 185 +#endif
 186 +
 187 +#endif /* _LTTNG_WRAPPER_KVM_X86_H */
 188 --
 189 2.36.1
 190