1IBV_POST_SEND(3)        Libibverbs Programmer's Manual        IBV_POST_SEND(3)
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NAME

6       ibv_post_send - post a list of work requests (WRs) to a send queue
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SYNOPSIS

9       #include <infiniband/verbs.h>
10
11       int ibv_post_send(struct ibv_qp *qp, struct ibv_send_wr *wr,
12                         struct ibv_send_wr **bad_wr);
13

DESCRIPTION

15       ibv_post_send()  posts  the linked list of work requests (WRs) starting
16       with wr to the send queue of the queue pair qp.   It  stops  processing
17       WRs  from  this list at the first failure (that can be detected immedi‐
18       ately while requests are being posted), and  returns  this  failing  WR
19       through bad_wr.
20
21       The  argument  wr  is  an  ibv_send_wr  struct,  as defined in <infini‐
22       band/verbs.h>.
23
24       struct ibv_send_wr {
25               uint64_t                wr_id;                  /* User defined WR ID */
26               struct ibv_send_wr     *next;                   /* Pointer to next WR in list, NULL if last WR */
27               struct ibv_sge         *sg_list;                /* Pointer to the s/g array */
28               int                     num_sge;                /* Size of the s/g array */
29               enum ibv_wr_opcode      opcode;                 /* Operation type */
30               int                     send_flags;             /* Flags of the WR properties */
31               union {
32                       __be32                  imm_data;               /* Immediate data (in network byte order) */
33                       uint32_t                invalidate_rkey;        /* Remote rkey to invalidate */
34               };
35               union {
36                       struct {
37                               uint64_t        remote_addr;    /* Start address of remote memory buffer */
38                               uint32_t        rkey;           /* Key of the remote Memory Region */
39                       } rdma;
40                       struct {
41                               uint64_t        remote_addr;    /* Start address of remote memory buffer */
42                               uint64_t        compare_add;    /* Compare operand */
43                               uint64_t        swap;           /* Swap operand */
44                               uint32_t        rkey;           /* Key of the remote Memory Region */
45                       } atomic;
46                       struct {
47                               struct ibv_ah  *ah;             /* Address handle (AH) for the remote node address */
48                               uint32_t        remote_qpn;     /* QP number of the destination QP */
49                               uint32_t        remote_qkey;    /* Q_Key number of the destination QP */
50                       } ud;
51               } wr;
52               union {
53                       struct {
54                               uint32_t remote_srqn;            /* Number of the remote SRQ */
55                       } xrc;
56               } qp_type;
57               union {
58                       struct {
59                               struct ibv_mw            *mw;             /* Memory window (MW) of type 2 to bind */
60                               uint32_t                 rkey;            /* The desired new rkey of the MW */
61                               struct ibv_mw_bind_info  bind_info;       /* MW additional bind information */
62                       } bind_mw;
63                       struct {
64                               void           *hdr;     /* Pointer address of inline header */
65                               uint16_t       hdr_sz;   /* Inline header size */
66                               uint16_t       mss; /* Maximum segment size for each TSO fragment */
67                       } tso;
68               };
69       };
70
71       struct ibv_mw_bind_info {
72               struct ibv_mr            *mr;             /* The Memory region (MR) to bind the MW to */
73               uint64_t                 addr;           /* The address the MW should start at */
74               uint64_t                 length;          /* The length (in bytes) the MW should span */
75               int                      mw_access_flags; /* Access flags to the MW. Use ibv_access_flags */
76       };
77
78       struct ibv_sge {
79               uint64_t                addr;                   /* Start address of the local memory buffer or number of bytes from the
80                                                                  start of the MR for MRs which are IBV_ZERO_BASED */
81               uint32_t                length;                 /* Length of the buffer */
82               uint32_t                lkey;                   /* Key of the local Memory Region */
83       };
84
85       Each QP Transport Service Type supports a specific set of  opcodes,  as
86       shown in the following table:
87
88       OPCODE                      | IBV_QPT_UD | IBV_QPT_UC | IBV_QPT_RC | IBV_QPT_XRC_SEND | IBV_QPT_RAW_PACKET
89       ----------------------------+------------+------------+------------+------------------+--------------------
90       IBV_WR_SEND                 |     X      |     X      |     X      |         X        |         X
91       IBV_WR_SEND_WITH_IMM        |     X      |     X      |     X      |         X        |
92       IBV_WR_RDMA_WRITE           |            |     X      |     X      |         X        |
93       IBV_WR_RDMA_WRITE_WITH_IMM  |            |     X      |     X      |         X        |
94       IBV_WR_RDMA_READ            |            |            |     X      |         X        |
95       IBV_WR_ATOMIC_CMP_AND_SWP   |            |            |     X      |         X        |
96       IBV_WR_ATOMIC_FETCH_AND_ADD |            |            |     X      |         X        |
97       IBV_WR_LOCAL_INV            |            |     X      |     X      |         X        |
98       IBV_WR_BIND_MW              |            |     X      |     X      |         X        |
99       IBV_WR_SEND_WITH_INV        |            |     X      |     X      |         X        |
100       IBV_WR_TSO                  |     X      |            |            |                  |         X
101
102       The  attribute  send_flags  describes  the  properties of the WR. It is
103       either 0 or the bitwise OR of one or more of the following flags:
104
105       IBV_SEND_FENCE  Set the fence indicator. Valid only for QPs with Trans‐
106       port Service Type IBV_QPT_RC
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108       IBV_SEND_SIGNALED   Set the completion notification indicator. Relevant
109       only if QP was created with sq_sig_all=0
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111       IBV_SEND_SOLICITED  Set the solicited event indicator. Valid  only  for
112       Send and RDMA Write with immediate
113
114       IBV_SEND_INLINE  Send data in given gather list as inline data
115              in  a  send WQE.  Valid only for Send and RDMA Write.  The L_Key
116              will not be checked.
117
118       IBV_SEND_IP_CSUM  Offload the IPv4 and TCP/UDP checksum calculation.
119              Valid only when device_cap_flags in device_attr  indicates  cur‐
120              rent QP is supported by checksum offload.
121

RETURN VALUE

123       ibv_post_send()  returns 0 on success, or the value of errno on failure
124       (which indicates the failure reason).
125

NOTES

127       The user should not alter or destroy  AHs  associated  with  WRs  until
128       request is fully executed and a work completion has been retrieved from
129       the corresponding completion queue (CQ) to avoid unexpected behavior.
130
131       The buffers used by a WR can only be safely reused after WR the request
132       is  fully  executed  and  a work completion has been retrieved from the
133       corresponding completion queue (CQ). However,  if  the  IBV_SEND_INLINE
134       flag  was  set,  the  buffer  can  be reused immediately after the call
135       returns.
136

SEE ALSO

138       ibv_create_qp(3),          ibv_create_ah(3),          ibv_post_recv(3),
139       ibv_post_srq_recv(3), ibv_poll_cq(3)
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AUTHORS

142       Dotan Barak <dotanba@gmail.com>
143
144       Majd Dibbiny <majd@mellanox.com>
145
146       Yishai Hadas <yishaih@mellanox.com>
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150libibverbs                        2006-10-31                  IBV_POST_SEND(3)
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