diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 93c4dfeb3a8fa0514f1a81cb4d14a7722a078ad4..a026b1606c997745044fd39526be68653d7a9050 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/nospec.h>
 #include <linux/prctl.h>
+#include <linux/sched/smt.h>
 
 #include <asm/spec-ctrl.h>
 #include <asm/cmdline.h>
@@ -343,16 +344,14 @@ void arch_smt_update(void)
 		return;
 
 	mutex_lock(&spec_ctrl_mutex);
-	mask = x86_spec_ctrl_base;
-	if (cpu_smt_control == CPU_SMT_ENABLED)
+
+	mask = x86_spec_ctrl_base & ~SPEC_CTRL_STIBP;
+	if (sched_smt_active())
 		mask |= SPEC_CTRL_STIBP;
-	else
-		mask &= ~SPEC_CTRL_STIBP;
 
 	if (mask != x86_spec_ctrl_base) {
 		pr_info("Spectre v2 cross-process SMT mitigation: %s STIBP\n",
-				cpu_smt_control == CPU_SMT_ENABLED ?
-				"Enabling" : "Disabling");
+			mask & SPEC_CTRL_STIBP ? "Enabling" : "Disabling");
 		x86_spec_ctrl_base = mask;
 		on_each_cpu(update_stibp_msr, NULL, 1);
 	}
diff --git a/include/linux/sched/smt.h b/include/linux/sched/smt.h
index c9e0be51411045b4de65b9e9d3b44de75e27ae88..59d3736c454cf85a7de69181af6377fae7dc10c6 100644
--- a/include/linux/sched/smt.h
+++ b/include/linux/sched/smt.h
@@ -15,4 +15,6 @@ static __always_inline bool sched_smt_active(void)
 static inline bool sched_smt_active(void) { return false; }
 #endif
 
+void arch_smt_update(void);
+
 #endif
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 3adecda21444632958c39adb5f3b1a5a7332a118..1699ff68c412f60ea55cd4f0929a3cfae7523516 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -10,6 +10,7 @@
 #include <linux/sched/signal.h>
 #include <linux/sched/hotplug.h>
 #include <linux/sched/task.h>
+#include <linux/sched/smt.h>
 #include <linux/unistd.h>
 #include <linux/cpu.h>
 #include <linux/oom.h>
@@ -346,6 +347,12 @@ void cpu_hotplug_enable(void)
 EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
 #endif	/* CONFIG_HOTPLUG_CPU */
 
+/*
+ * Architectures that need SMT-specific errata handling during SMT hotplug
+ * should override this.
+ */
+void __weak arch_smt_update(void) { }
+
 #ifdef CONFIG_HOTPLUG_SMT
 enum cpuhp_smt_control cpu_smt_control __read_mostly = CPU_SMT_ENABLED;
 EXPORT_SYMBOL_GPL(cpu_smt_control);
@@ -982,6 +989,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
 	 * concurrent CPU hotplug via cpu_add_remove_lock.
 	 */
 	lockup_detector_cleanup();
+	arch_smt_update();
 	return ret;
 }
 
@@ -1110,6 +1118,7 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target)
 	ret = cpuhp_up_callbacks(cpu, st, target);
 out:
 	cpus_write_unlock();
+	arch_smt_update();
 	return ret;
 }
 
@@ -2026,12 +2035,6 @@ static void cpuhp_online_cpu_device(unsigned int cpu)
 	kobject_uevent(&dev->kobj, KOBJ_ONLINE);
 }
 
-/*
- * Architectures that need SMT-specific errata handling during SMT hotplug
- * should override this.
- */
-void __weak arch_smt_update(void) { };
-
 static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
 {
 	int cpu, ret = 0;