staticvoidvhost_zerocopy_callback(struct ubuf_info *ubuf,boolsuccess){structvhost_net_ubuf_ref*ubufs=ubuf->ctx;structvhost_virtqueue*vq=ubufs->vq;intcnt;rcu_read_lock_bh();/* set len to mark this desc buffers done DMA */vq->heads[ubuf->desc].len = success ? VHOST_DMA_DONE_LEN...