int (*query_port)(struct ibv_context *context, uint8_t port_num,
struct ibv_port_attr *port_attr);
struct ibv_comp_channel *(*create_comp_channel)
int (*query_port)(struct ibv_context *context, uint8_t port_num,
struct ibv_port_attr *port_attr);
struct ibv_comp_channel *(*create_comp_channel)