virtnet_rss_hdr_size
vi->rss_hdr = devm_kzalloc(&vi->vdev->dev, virtnet_rss_hdr_size(vi), GFP_KERNEL);
sg_set_buf(&sgs[0], vi->rss_hdr, virtnet_rss_hdr_size(vi));
vi->rss_hdr = devm_kzalloc(&vdev->dev, virtnet_rss_hdr_size(vi), GFP_KERNEL);