ibv_create_qp_ex man page

ibv_create_qp_ex, ibv_destroy_qp ā€” create or destroy a queue pair (QP)


#include <infiniband/verbs.h>

struct ibv_qp *ibv_create_qp_ex(struct ibv_context *context,
                                struct ibv_qp_init_attr_ex *qp_init_attr);

int ibv_destroy_qp(struct ibv_qp *qp);


ibv_create_qp_ex() creates a queue pair (QP) associated with the protection domain pd. The argument qp_init_attr_ex is an ibv_qp_init_attr_ex struct, as defined in <infiniband/verbs.h>.

struct ibv_qp_init_attr_ex {
void                   *qp_context;     /* Associated context of the QP */
struct ibv_cq          *send_cq;        /* CQ to be associated with the Send Queue (SQ) */
struct ibv_cq          *recv_cq;        /* CQ to be associated with the Receive Queue (RQ) */
struct ibv_srq         *srq;            /* SRQ handle if QP is to be associated with an SRQ, otherwise NULL */
struct ibv_qp_cap       cap;            /* QP capabilities */
enum ibv_qp_type        qp_type;        /* QP Transport Service Type: IBV_QPT_RC, IBV_QPT_UC, IBV_QPT_UD or IBV_QPT_RAW_PACKET */
int                     sq_sig_all;     /* If set, each Work Request (WR) submitted to the SQ generates a completion entry */
uint32_t                comp_mask;	/* Identifies valid fields */
struct ibv_pd          *pd;		/* PD to be associated with the QP */
struct ibv_xrcd        *xrcd;		/* XRC domain to be associated with the target QP */
enum ibv_qp_create_flags create_flags;	/* Creation flags for this QP */
uint16_t                max_tso_header; /* Maximum TSO header size */
struct ibv_rwq_ind_table *rwq_ind_tbl;  /* Indirection table to be associated with the QP */
struct ibv_rx_hash_conf  rx_hash_conf;  /* RX hash configuration to be used */
uint32_t                source_qpn;     /* Source QP number, creation flag IBV_QP_CREATE_SOURCE_QPN should be set, few NOTEs below */

struct ibv_qp_cap {
uint32_t                max_send_wr;    /* Requested max number of outstanding WRs in the SQ */
uint32_t                max_recv_wr;    /* Requested max number of outstanding WRs in the RQ */
uint32_t                max_send_sge;   /* Requested max number of scatter/gather (s/g) elements in a WR in the SQ */
uint32_t                max_recv_sge;   /* Requested max number of s/g elements in a WR in the SQ */
uint32_t                max_inline_data;/* Requested max number of data (bytes) that can be posted inline to the SQ, otherwise 0 */
enum ibv_qp_create_flags {
IBV_QP_CREATE_BLOCK_SELF_MCAST_LB       = 1 << 1, /* Prevent self multicast loopback */
IBV_QP_CREATE_SCATTER_FCS               = 1 << 8, /* FCS field will be scattered to host memory */
IBV_QP_CREATE_CVLAN_STRIPPING           = 1 << 9, /* CVLAN field will be stripped from incoming packets */
IBV_QP_CREATE_SOURCE_QPN                = 1 << 10, /* The created QP will use the source_qpn as its wire QP number */
IBV_QP_CREATE_PCI_WRITE_END_PADDING     = 1 << 11, /* Incoming packets will be padded to cacheline size */
struct ibv_rx_hash_conf {
uint8_t                rx_hash_function;       /* RX hash function, use enum ibv_rx_hash_function_flags */
uint8_t                rx_hash_key_len;        /* RX hash key length */
uint8_t                *rx_hash_key;           /* RX hash key data */
uint64_t               rx_hash_fields_mask;    /* RX fields that should participate in the hashing, use enum ibv_rx_hash_fields */
enum ibv_rx_hash_fields {
IBV_RX_HASH_SRC_IPV4            = 1 << 0,
IBV_RX_HASH_DST_IPV4            = 1 << 1,
IBV_RX_HASH_SRC_IPV6            = 1 << 2,
IBV_RX_HASH_DST_IPV6            = 1 << 3,
IBV_RX_HASH_SRC_PORT_TCP        = 1 << 4,
IBV_RX_HASH_DST_PORT_TCP        = 1 << 5,
IBV_RX_HASH_SRC_PORT_UDP        = 1 << 6,
IBV_RX_HASH_DST_PORT_UDP        = 1 << 7,
/* When using tunneling protocol, e.g. VXLAN, then we have an inner (encapsulated packet) and outer.
 * For applying RSS on the inner packet, then the following field should be set with one of the L3/L4 fields.
IBV_RX_HASH_INNER		= (1UL << 31),

The function ibv_create_qp_ex() will update the qp_init_attr_ex->cap struct with the actual QP values of the QP that was created; the values will be greater than or equal to the values requested.

ibv_destroy_qp() destroys the QP qp.

Return Value

ibv_create_qp_ex() returns a pointer to the created QP, or NULL if the request fails. Check the QP number (qp_num) in the returned QP.

ibv_destroy_qp() returns 0 on success, or the value of errno on failure (which indicates the failure reason).


The attributes max_recv_wr and max_recv_sge are ignored by ibv_create_qp_ex() if the QP is to be associated with an SRQ.

The attribute source_qpn is supported only on UD QP, without flow steering RX should not be possible.

ibv_destroy_qp() fails if the QP is attached to a multicast group.

See Also

ibv_alloc_pd(3), ibv_modify_qp(3), ibv_query_qp(3), ibv_create_rwq_ind_table(3)


Yishai Hadas <yishaih@mellanox.com>

Referenced By

ibv_create_rwq_ind_table(3), ibv_open_qp(3), ibv_open_xrcd(3).

2013-06-26 libibverbs Libibverbs Programmer's Manual