diff --git a/sys/dev/acpica/acpi_apei.c b/sys/dev/acpica/acpi_apei.c
--- a/sys/dev/acpica/acpi_apei.c
+++ b/sys/dev/acpica/acpi_apei.c
@@ -732,7 +732,8 @@
 			TAILQ_INSERT_TAIL(&sc->nges.ges, ge, nlink);
 			if (sc->nges.swi_ih == NULL) {
 				swi_add(&clk_intr_event, "apei", apei_nmi_swi,
-				    &sc->nges, SWI_CLOCK, INTR_MPSAFE,
+				    &sc->nges, SWI_CLOCK,
+				    INTR_MPSAFE | INTR_MULTIPROC,
 				    &sc->nges.swi_ih);
 				apei_nmi_nges = &sc->nges;
 				apei_nmi = apei_nmi_handler;
diff --git a/sys/kern/kern_intr.c b/sys/kern/kern_intr.c
--- a/sys/kern/kern_intr.c
+++ b/sys/kern/kern_intr.c
@@ -286,8 +286,8 @@
 	struct intr_event *ie;
 	va_list ap;
 
-	/* The only valid flag during creation is IE_SOFT. */
-	if ((flags & ~IE_SOFT) != 0)
+	/* The flags valid during creation are IE_SOFT and IE_MULTIPROC. */
+	if ((flags & ~(IE_SOFT | IE_MULTIPROC)) != 0)
 		return (EINVAL);
 	ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO);
 	ie->ie_source = source;
@@ -608,6 +608,19 @@
 	if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
 		return (EINVAL);
 
+	if ((flags & INTR_MULTIPROC) && !(ie->ie_flags & IE_MULTIPROC)) {
+#if defined(INVARIANTS) || defined(DEBUG)
+		printf("%s: Requested multi-processor interupt, but got "
+		    "uniprocessor interrupt\n", name);
+#endif
+		return (ENODEV);
+	}
+#if defined(INVARIANTS) || defined(DEBUG)
+	if (!(flags & INTR_MULTIPROC) && (ie->ie_flags & IE_MULTIPROC))
+		printf("%s: Requested uniprocessor interupt, but got "
+		    "multi-processor interrupt\n", name);
+#endif
+
 	/* Allocate and populate an interrupt handler structure. */
 	ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
 	ih->ih_filter = filter;
@@ -1059,18 +1072,22 @@
 	    void *arg, int pri, enum intr_type flags, void **cookiep)
 {
 	struct intr_event *ie;
+	int ieflags = IE_SOFT;
 	int error = 0;
 
 	if (flags & INTR_ENTROPY)
 		return (EINVAL);
 
+	if (flags & INTR_MULTIPROC)
+		ieflags |= IE_MULTIPROC;
+
 	ie = (eventp != NULL) ? *eventp : NULL;
 
 	if (ie != NULL) {
 		if (!(ie->ie_flags & IE_SOFT))
 			return (EINVAL);
 	} else {
-		error = intr_event_create(&ie, NULL, IE_SOFT, 0,
+		error = intr_event_create(&ie, NULL, ieflags, 0,
 		    NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri);
 		if (error)
 			return (error);
@@ -1625,8 +1642,11 @@
 start_softintr(void *dummy)
 {
 
+	KASSERT(clk_intr_event == NULL, ("clk_intr_event non-NULL at %s()",
+	    __func__));
+
 	if (swi_add(&clk_intr_event, "clk", NULL, NULL, SWI_CLOCK,
-	    INTR_MPSAFE, NULL))
+	    INTR_MPSAFE | INTR_MULTIPROC, NULL))
 		panic("died while creating clk swi ithread");
 }
 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr,
diff --git a/sys/kern/subr_intr.c b/sys/kern/subr_intr.c
--- a/sys/kern/subr_intr.c
+++ b/sys/kern/subr_intr.c
@@ -626,12 +626,15 @@
 isrc_event_create(struct intr_irqsrc *isrc)
 {
 	struct intr_event *ie;
+	u_int flags = 0;
 	int error;
 
 	if (isrc->isrc_event != NULL)
 		return (0);
 
-	error = intr_event_create(&ie, isrc, 0, isrc->isrc_irq,
+	if (isrc->isrc_flags & (INTR_ISRCF_IPI | INTR_ISRCF_PPI))
+		flags |= IE_MULTIPROC;
+	error = intr_event_create(&ie, isrc, flags, isrc->isrc_irq,
 	    intr_isrc_pre_ithread, intr_isrc_post_ithread, intr_isrc_post_filter,
 	    intr_isrc_assign_cpu, "%s:", isrc->isrc_name);
 	if (error)
diff --git a/sys/sys/bus.h b/sys/sys/bus.h
--- a/sys/sys/bus.h
+++ b/sys/sys/bus.h
@@ -281,7 +281,8 @@
 	INTR_MD1 = 4096,		/* flag reserved for MD use */
 	INTR_MD2 = 8192,		/* flag reserved for MD use */
 	INTR_MD3 = 16384,		/* flag reserved for MD use */
-	INTR_MD4 = 32768		/* flag reserved for MD use */
+	INTR_MD4 = 32768,		/* flag reserved for MD use */
+	INTR_MULTIPROC = 0x10000,	/* interrupt occurs on multiple procs */
 };
 
 enum intr_trigger {
diff --git a/sys/sys/interrupt.h b/sys/sys/interrupt.h
--- a/sys/sys/interrupt.h
+++ b/sys/sys/interrupt.h
@@ -132,6 +132,7 @@
 /* Interrupt event flags kept in ie_flags. */
 #define	IE_SOFT		0x000001	/* Software interrupt. */
 #define	IE_ADDING_THREAD 0x000004	/* Currently building an ithread. */
+#define	IE_MULTIPROC	0x000008	/* Interrupt occurs on multiple procs */
 
 /* Flags to pass to swi_sched. */
 #define	SWI_FROMNMI	0x1