.\" -*- nroff -*- .\" Licensed under the OpenIB.org BSD license (FreeBSD Variant) - See COPYING.md .\" .TH IBV_CREATE_CQ_EX 3 2016-05-08 libibverbs "Libibverbs Programmer's Manual" .SH "NAME" ibv_create_cq_ex \- create a completion queue (CQ) .SH "SYNOPSIS" .nf .B #include .sp .BI "struct ibv_cq_ex *ibv_create_cq_ex(struct ibv_context " "*context" ", .BI " struct ibv_create_cq_attr_ex " "*cq_attr" ); .fi .SH "DESCRIPTION" .B ibv_create_cq_ex() creates a completion queue (CQ) for RDMA device context .I context\fR. The argument .I cq_attr is a pointer to struct ibv_cq_init_attr_ex as defined in . .PP .nf struct ibv_cq_init_attr_ex { .in +8 int cqe; /* Minimum number of entries required for CQ */ void *cq_context; /* Consumer-supplied context returned for completion events */ struct ibv_comp_channel *channel; /* Completion channel where completion events will be queued. May be NULL if completion events will not be used. */ int comp_vector; /* Completion vector used to signal completion events. Must be >= 0 and < context->num_comp_vectors. */ uint64_t wc_flags; /* The wc_flags that should be returned in ibv_poll_cq_ex. Or'ed bit of enum ibv_wc_flags_ex. */ uint32_t comp_mask; /* compatibility mask (extended verb). */ uint32_t flags /* One or more flags from enum ibv_create_cq_attr_flags */ .in -8 }; enum ibv_wc_flags_ex { IBV_WC_EX_WITH_BYTE_LEN = 1 << 0, /* Require byte len in WC */ IBV_WC_EX_WITH_IMM = 1 << 1, /* Require immediate in WC */ IBV_WC_EX_WITH_QP_NUM = 1 << 2, /* Require QP number in WC */ IBV_WC_EX_WITH_SRC_QP = 1 << 3, /* Require source QP in WC */ IBV_WC_EX_WITH_SLID = 1 << 4, /* Require slid in WC */ IBV_WC_EX_WITH_SL = 1 << 5, /* Require sl in WC */ IBV_WC_EX_WITH_DLID_PATH_BITS = 1 << 6, /* Require dlid path bits in WC */ IBV_WC_EX_WITH_COMPLETION_TIMESTAMP = 1 << 7, /* Require completion timestamp in WC /* IBV_WC_EX_WITH_CVLAN = 1 << 8, /* Require VLAN info in WC */ IBV_WC_EX_WITH_FLOW_TAG = 1 << 9, /* Require flow tag in WC */ }; enum ibv_cq_init_attr_mask { IBV_CQ_INIT_ATTR_MASK_FLAGS = 1 << 0, }; enum ibv_create_cq_attr_flags { IBV_CREATE_CQ_ATTR_SINGLE_THREADED = 1 << 0, /* This CQ is used from a single threaded, thus no locking is required */ }; .SH "Polling an extended CQ" In order to poll an extended CQ efficiently, a user could use the following functions. .TP .B Completion iterator functions .BI "int ibv_start_poll(struct ibv_cq_ex " "*cq" ", struct ibv_poll_cq_attr " "*attr") .br Start polling a batch of work completions. .I attr is given in order to make this function easily extensible in the future. This function either returns 0 on success or an error code otherwise. When no completions are available on the CQ, ENOENT is returned, but the CQ remains in a valid state. On success, querying the completion's attribute could be done using the query functions described below. If an error code is given, end_poll shouldn't be called. .BI "int ibv_next_poll(struct ibv_cq_ex " "*cq") .br This function is called in order to get the next work completion. It has to be called after .I start_poll and before .I end_poll are called. This function either returns 0 on success or an error code otherwise. When no completions are available on the CQ, ENOENT is returned, but the CQ remains in a valid state. On success, querying the completion's attribute could be done using the query functions described below. If an error code is given, end_poll should still be called, indicating this is the end of the polled batch. .BI "void ibv_end_poll(struct ibv_cq_ex " "*cq") .br This function indicates the end of polling batch of work completions. After calling this function, the user should start a new batch by calling .I start_poll. .TP .B Polling fields in the completion Below members and functions are used in order to poll the current completion. The current completion is the completion which the iterator points to (start_poll and next_poll advances this iterator). Only fields that the user requested via wc_flags in ibv_create_cq_ex could be queried. In addition, some fields are only valid in certain opcodes and status codes. .BI "uint64_t wr_id - Can be accessed directly from struct ibv_cq_ex". .BI "enum ibv_wc_status - Can be accessed directly from struct ibv_cq_ex". .BI "enum ibv_wc_opcode ibv_wc_read_opcode(struct ibv_cq_ex " "*cq"); \c Get the opcode from the current completion. .BI "uint32_t ibv_wc_read_vendor_err(struct ibv_cq_ex " "*cq"); \c Get the vendor error from the current completion. .BI "uint32_t ibv_wc_read_byte_len(struct ibv_cq_ex " "*cq"); \c Get the vendor error from the current completion. .BI "uint32_t ibv_wc_read_imm_data(struct ibv_cq_ex " "*cq"); \c Get the immediate data field from the current completion. .BI "uint32_t ibv_wc_read_qp_num(struct ibv_cq_ex " "*cq"); \c Get the QP number field from the current completion. .BI "uint32_t ibv_wc_read_src_qp(struct ibv_cq_ex " "*cq"); \c Get the source QP number field from the current completion. .BI "int ibv_wc_read_wc_flags(struct ibv_cq_ex " "*cq"); \c Get the QP flags field from the current completion. .BI "uint16_t ibv_wc_read_pkey_index(struct ibv_cq_ex " "*cq"); \c Get the pkey index field from the current completion. .BI "uint32_t ibv_wc_read_slid(struct ibv_cq_ex " "*cq"); \c Get the slid field from the current completion. .BI "uint8_t ibv_wc_read_sl(struct ibv_cq_ex " "*cq"); \c Get the sl field from the current completion. .BI "uint8_t ibv_wc_read_dlid_path_bits(struct ibv_cq_ex " "*cq"); \c Get the dlid_path_bits field from the current completion. .BI "uint64_t ibv_wc_read_completion_ts(struct ibv_cq_ex " "*cq"); \c Get the completion timestamp from the current completion. .BI "uint16_t ibv_wc_read_cvlan(struct ibv_cq_ex " "*cq"); \c Get the CVLAN field from the current completion. .BI "uint32_t ibv_wc_read_flow_tag(struct ibv_cq_ex " "*cq"); \c Get flow tag from the current completion. .SH "RETURN VALUE" .B ibv_create_cq_ex() returns a pointer to the CQ, or NULL if the request fails. .SH "NOTES" .B ibv_create_cq_ex() may create a CQ with size greater than or equal to the requested size. Check the cqe attribute in the returned CQ for the actual size. .PP CQ should be destroyed with ibv_destroy_cq. .PP .SH "SEE ALSO" .BR ibv_create_cq (3), .BR ibv_destroy_cq (3), .BR ibv_resize_cq (3), .BR ibv_req_notify_cq (3), .BR ibv_ack_cq_events (3), .BR ibv_create_qp (3) .SH "AUTHORS" .TP Matan Barak