#include <infiniband/verbs.h> int ibv_query_port(struct ibv_context *context, uint8_t port_num, struct ibv_port_attr *port_attr);
struct ibv_port_attr { enum ibv_port_state state; /* Logical port state */ enum ibv_mtu max_mtu; /* Max MTU supported by port */ enum ibv_mtu active_mtu; /* Actual MTU */ int gid_tbl_len; /* Length of source GID table */ uint32_t port_cap_flags; /* Port capabilities */ uint32_t max_msg_sz; /* Maximum message size */ uint32_t bad_pkey_cntr; /* Bad P_Key counter */ uint32_t qkey_viol_cntr; /* Q_Key violation counter */ uint16_t pkey_tbl_len; /* Length of partition table */ uint16_t lid; /* Base port LID */ uint16_t sm_lid; /* SM LID */ uint8_t lmc; /* LMC of LID */ uint8_t max_vl_num; /* Maximum number of VLs */ uint8_t sm_sl; /* SM service level */ uint8_t subnet_timeout; /* Subnet propagation delay */ uint8_t init_type_reply;/* Type of initialization performed by SM */ uint8_t active_width; /* Currently active link width */ uint8_t active_speed; /* Currently active link speed */ uint8_t phys_state; /* Physical port state */ uint8_t link_layer; /* link layer protocol of the port */ uint8_t flags; /* Port flags */ uint16_t port_cap_flags2;/* Port capabilities */ }; possible values for the link layer field are IBV_LINK_LAYER_INFINIBAND, IBV_LINK_LAYER_ETHERNET, or IBV_LINK_LAYER_UNSPECIFIED. supported port flags: IBV_QPF_GRH_REQUIRED - When this flag is set, the applications must create all AH with GRH configured.