Index: head/sys/x86/acpica/acpi_wakeup.c
===================================================================
--- head/sys/x86/acpica/acpi_wakeup.c
+++ head/sys/x86/acpica/acpi_wakeup.c
@@ -209,6 +209,10 @@
 {
 	ACPI_STATUS	status;
 	struct pcb	*pcb;
+#ifdef __amd64__
+	struct pcpu *pc;
+	int i;
+#endif
 
 	if (sc->acpi_wakeaddr == 0ul)
 		return (-1);	/* couldn't alloc wake memory */
@@ -236,6 +240,14 @@
 		if (!CPU_EMPTY(&suspcpus) && suspend_cpus(suspcpus) == 0) {
 			device_printf(sc->acpi_dev, "Failed to suspend APs\n");
 			return (0);	/* couldn't sleep */
+		}
+#endif
+#ifdef __amd64__
+		hw_ibrs_active = 0;
+		cpu_stdext_feature3 = 0;
+		CPU_FOREACH(i) {
+			pc = pcpu_find(i);
+			pc->pc_ibpb_set = 0;
 		}
 #endif
 
Index: head/sys/x86/include/x86_var.h
===================================================================
--- head/sys/x86/include/x86_var.h
+++ head/sys/x86/include/x86_var.h
@@ -83,7 +83,8 @@
 extern	int	use_xsave;
 extern	uint64_t xsave_mask;
 extern	u_int	max_apic_id;
-extern int	pti;
+extern	int	pti;
+extern	int	hw_ibrs_active;
 
 struct	pcb;
 struct	thread;