Index: sys/arm64/arm64/gic_v3.c
===================================================================
--- sys/arm64/arm64/gic_v3.c
+++ sys/arm64/arm64/gic_v3.c
@@ -594,9 +594,16 @@
 	if (data == NULL)
 		return (ENOTSUP);
 
-	error = do_gic_v3_map_intr(dev, data, &irq, &pol, &trig);
-	if (error != 0)
-		return (error);
+	if (data->type == INTR_MAP_DATA_FDT) {
+		error = do_gic_v3_map_intr(dev, data, &irq, &pol, &trig);
+		if (error != 0)
+			return (error);
+	} else if (data->type == INTR_MAP_DATA_MSI) {
+		pol = INTR_POLARITY_HIGH;
+		trig = INTR_TRIGGER_EDGE;
+		irq = gi->gi_irq;
+	} else
+		return (ENOTSUP);
 
 	if (gi->gi_irq != irq || pol == INTR_POLARITY_CONFORM ||
 	    trig == INTR_TRIGGER_CONFORM)