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
@@ -3,6 +3,7 @@
  *
  * Copyright (c) 1997, Stefan Esser <se@freebsd.org>
  * All rights reserved.
+ * Copyright © 2023 Elliott Mitchell
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -286,8 +287,8 @@
 	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;
@@ -1059,18 +1060,22 @@
 	    void *arg, int pri, enum intr_type flags, void **cookiep)
 {
 	struct intr_event *ie;
+	int eflags = IE_SOFT;
 	int error = 0;
 
 	if (flags & INTR_ENTROPY)
 		return (EINVAL);
 
+	if (flags & INTR_MULTIPROC)
+		eflags |= 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, eflags, 0,
 		    NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri);
 		if (error)
 			return (error);
@@ -1626,7 +1631,7 @@
 {
 
 	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
@@ -2,7 +2,7 @@
  * Copyright (c) 2015-2016 Svatopluk Kraus
  * Copyright (c) 2015-2016 Michal Meloun
  * All rights reserved.
- * Copyright © 2022 Elliott Mitchell
+ * Copyright © 2022-2023 Elliott Mitchell
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -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