vring_unmap_extra_packed
vring_unmap_extra_packed(vq, &extra[i]);
vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]);
vring_unmap_extra_packed(vq, &vq->packed.desc_extra[i]);
vring_unmap_extra_packed(vq,
vring_unmap_extra_packed(vq, &extra[i]);