void *(*dr_create_flow_tbl)(void *domain, uint32_t level);
int (*dr_destroy_flow_tbl)(void *tbl);
void *(*dr_create_domain)(struct ibv_context *ctx,
void *(*dr_create_flow_tbl)(void *domain, uint32_t level);
int (*dr_destroy_flow_tbl)(void *tbl);
void *(*dr_create_domain)(struct ibv_context *ctx,