@@ -29,8 +29,10 @@ void __noreturn machine_real_restart(unsigned int type);
typedef void (cpu_emergency_virt_cb)(void);
void cpu_emergency_register_virt_callback(cpu_emergency_virt_cb *callback);
void cpu_emergency_unregister_virt_callback(cpu_emergency_virt_cb *callback);
-#endif
void cpu_emergency_disable_virtualization(void);
+#else
+static inline void cpu_emergency_disable_virtualization(void) {}
+#endif
typedef void (*nmi_shootdown_cb)(int, struct pt_regs*);
void nmi_panic_self_stop(struct pt_regs *regs);
@@ -530,6 +530,48 @@ static inline void kb_wait(void)
static inline void nmi_shootdown_cpus_on_restart(void);
+#if IS_ENABLED(CONFIG_KVM_INTEL) || IS_ENABLED(CONFIG_KVM_AMD)
+/* RCU-protected callback to disable virtualization prior to reboot. */
+static cpu_emergency_virt_cb __rcu *cpu_emergency_virt_callback;
+
+void cpu_emergency_register_virt_callback(cpu_emergency_virt_cb *callback)
+{
+ if (WARN_ON_ONCE(rcu_access_pointer(cpu_emergency_virt_callback)))
+ return;
+
+ rcu_assign_pointer(cpu_emergency_virt_callback, callback);
+}
+EXPORT_SYMBOL_GPL(cpu_emergency_register_virt_callback);
+
+void cpu_emergency_unregister_virt_callback(cpu_emergency_virt_cb *callback)
+{
+ if (WARN_ON_ONCE(rcu_access_pointer(cpu_emergency_virt_callback) != callback))
+ return;
+
+ rcu_assign_pointer(cpu_emergency_virt_callback, NULL);
+ synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(cpu_emergency_unregister_virt_callback);
+
+/*
+ * Disable virtualization, i.e. VMX or SVM, to ensure INIT is recognized during
+ * reboot. VMX blocks INIT if the CPU is post-VMXON, and SVM blocks INIT if
+ * GIF=0, i.e. if the crash occurred between CLGI and STGI.
+ */
+void cpu_emergency_disable_virtualization(void)
+{
+ cpu_emergency_virt_cb *callback;
+
+ lockdep_assert_irqs_disabled();
+
+ rcu_read_lock();
+ callback = rcu_dereference(cpu_emergency_virt_callback);
+ if (callback)
+ callback();
+ rcu_read_unlock();
+}
+#endif /* CONFIG_KVM_INTEL || CONFIG_KVM_AMD */
+
static void emergency_reboot_disable_virtualization(void)
{
/* Just make sure we won't change CPUs while doing this */
@@ -787,53 +829,9 @@ void machine_crash_shutdown(struct pt_regs *regs)
}
#endif
-#if IS_ENABLED(CONFIG_KVM_INTEL) || IS_ENABLED(CONFIG_KVM_AMD)
-/* RCU-protected callback to disable virtualization prior to reboot. */
-static cpu_emergency_virt_cb __rcu *cpu_emergency_virt_callback;
-
-void cpu_emergency_register_virt_callback(cpu_emergency_virt_cb *callback)
-{
- if (WARN_ON_ONCE(rcu_access_pointer(cpu_emergency_virt_callback)))
- return;
-
- rcu_assign_pointer(cpu_emergency_virt_callback, callback);
-}
-EXPORT_SYMBOL_GPL(cpu_emergency_register_virt_callback);
-
-void cpu_emergency_unregister_virt_callback(cpu_emergency_virt_cb *callback)
-{
- if (WARN_ON_ONCE(rcu_access_pointer(cpu_emergency_virt_callback) != callback))
- return;
-
- rcu_assign_pointer(cpu_emergency_virt_callback, NULL);
- synchronize_rcu();
-}
-EXPORT_SYMBOL_GPL(cpu_emergency_unregister_virt_callback);
-#endif
-
/* This is the CPU performing the emergency shutdown work. */
int crashing_cpu = -1;
-/*
- * Disable virtualization, i.e. VMX or SVM, to ensure INIT is recognized during
- * reboot. VMX blocks INIT if the CPU is post-VMXON, and SVM blocks INIT if
- * GIF=0, i.e. if the crash occurred between CLGI and STGI.
- */
-void cpu_emergency_disable_virtualization(void)
-{
- lockdep_assert_irqs_disabled();
-
-#if IS_ENABLED(CONFIG_KVM_INTEL) || IS_ENABLED(CONFIG_KVM_AMD)
- cpu_emergency_virt_cb *callback;
-
- rcu_read_lock();
- callback = rcu_dereference(cpu_emergency_virt_callback);
- if (callback)
- callback();
- rcu_read_unlock();
-#endif
-}
-
#if defined(CONFIG_SMP)
static nmi_shootdown_cb shootdown_callback;
Move the various "disable virtualization" helpers above the emergency reboot path so that emergency_reboot_disable_virtualization() can be stubbed out in a future patch if neither KVM_INTEL nor KVM_AMD is enabled, i.e. if there is no in-tree user of CPU virtualization. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/include/asm/reboot.h | 4 +- arch/x86/kernel/reboot.c | 86 +++++++++++++++++------------------ 2 files changed, 45 insertions(+), 45 deletions(-)