Index: head/sys/arm/arm/gic_acpi.c
===================================================================
--- head/sys/arm/arm/gic_acpi.c
+++ head/sys/arm/arm/gic_acpi.c
@@ -331,9 +331,21 @@
 	return (BUS_PROBE_DEFAULT);
 }
 
+static int
+arm_gicv2m_acpi_attach(device_t dev)
+{
+	struct arm_gicv2m_softc *sc;
+
+	sc = device_get_softc(dev);
+	sc->sc_xref = ACPI_MSI_XREF;
+
+	return (arm_gicv2m_attach(dev));
+}
+
 static device_method_t arm_gicv2m_acpi_methods[] = {
 	/* Device interface */
 	DEVMETHOD(device_probe,		arm_gicv2m_acpi_probe),
+	DEVMETHOD(device_attach,	arm_gicv2m_acpi_attach),
 
 	/* End */
 	DEVMETHOD_END