mlx4_ib_find_real_gid
*slave = mlx4_ib_find_real_gid(ibdev, port, gid.global.interface_id);
slave = mlx4_ib_find_real_gid(ibdev, port,
int mlx4_ib_find_real_gid(struct ib_device *ibdev, u32 port, __be64 guid);