mlx5_wqe_xrc_seg
max_overhead_xrc = sizeof(struct mlx5_wqe_xrc_seg);
*wqe += sizeof(struct mlx5_wqe_xrc_seg);
size += sizeof(struct mlx5_wqe_xrc_seg);
sizeof(struct mlx5_wqe_xrc_seg) -
struct mlx5_wqe_xrc_seg *xrc;