VIRTIO_CONFIG1_DEVICE_STATUS
old = bus_space_read_1(iot, ioh, VIRTIO_CONFIG1_DEVICE_STATUS);
bus_space_write_1(iot, ioh, VIRTIO_CONFIG1_DEVICE_STATUS,
VIRTIO_CONFIG1_DEVICE_STATUS);
bus_space_write_1(iot, ioh, VIRTIO_CONFIG1_DEVICE_STATUS,
bus_space_write_1(iot, ioh, VIRTIO_CONFIG1_DEVICE_STATUS,