fill_vec_buf(struct virtio_net *dev, struct vhost_virtqueue *vq,
uint32_t avail_idx, uint32_t *vec_idx,
struct buf_vector *buf_vec, uint16_t *desc_chain_head,
fill_vec_buf(struct virtio_net *dev, struct vhost_virtqueue *vq,
uint32_t avail_idx, uint32_t *vec_idx,
struct buf_vector *buf_vec, uint16_t *desc_chain_head,