virtio_setup_intr
error = virtio_setup_intr(dev, i, VTBALLOON_SLZ(sc));
error = virtio_setup_intr(dev, i,
error = virtio_setup_intr(sc->vtnet_dev, i,
error = virtio_setup_intr(dev, i, sc->vtnet_intr_slz[i]);
error = virtio_setup_intr(dev, i, NULL);
int virtio_setup_intr(device_t dev, uint irq, lwkt_serialize_t);