static int vhost_net_set_ubuf_info(struct vhost_net *n)
{
	bool zcopy;
	int i;

	for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
		zcopy = vhost_net_zcopy_mask & (0x1 << i);
		if (!zcopy)
			continue;
		n->vqs[i].ubuf_info =
			kmalloc_array(UIO_MAXIOV,
				      sizeof(*n->vqs[i].ubuf_info),
				      GFP_KERNEL);
		if  (!n->vqs[i].ubuf_info)
			goto err;
	}
	return 0;

err:
	vhost_net_clear_ubuf_info(n);
	return -ENOMEM;
}