import 15.2.0 Octopus source

[ceph.git] / ceph / src / spdk / lib / nvme / nvme_rdma.c

/*-
 *   BSD LICENSE
 *
 *   Copyright (c) Intel Corporation.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * NVMe over RDMA transport
 */

#include "spdk/stdinc.h"

#include <infiniband/verbs.h>
#include <rdma/rdma_cma.h>
#include <rdma/rdma_verbs.h>

#include "spdk/assert.h"
#include "spdk/log.h"
#include "spdk/trace.h"
#include "spdk/event.h"
#include "spdk/queue.h"
#include "spdk/nvme.h"
#include "spdk/nvmf_spec.h"
#include "spdk/string.h"
#include "spdk/endian.h"
#include "spdk/likely.h"

#include "nvme_internal.h"

#define NVME_RDMA_TIME_OUT_IN_MS 2000
#define NVME_RDMA_RW_BUFFER_SIZE 131072

/*
 * NVME RDMA qpair Resource Defaults
 */
#define NVME_RDMA_DEFAULT_TX_SGE                2
#define NVME_RDMA_DEFAULT_RX_SGE                1


/* Max number of NVMe-oF SGL descriptors supported by the host */
#define NVME_RDMA_MAX_SGL_DESCRIPTORS           16
struct spdk_nvmf_cmd {
        struct spdk_nvme_cmd cmd;
        struct spdk_nvme_sgl_descriptor sgl[NVME_RDMA_MAX_SGL_DESCRIPTORS];
};

struct spdk_nvme_rdma_hooks g_nvme_hooks = {};

/* Mapping from virtual address to ibv_mr pointer for a protection domain */
struct spdk_nvme_rdma_mr_map {
        struct ibv_pd                           *pd;
        struct spdk_mem_map                     *map;
        uint64_t                                ref;
        LIST_ENTRY(spdk_nvme_rdma_mr_map)       link;
};

/* NVMe RDMA transport extensions for spdk_nvme_ctrlr */
struct nvme_rdma_ctrlr {
        struct spdk_nvme_ctrlr                  ctrlr;

        struct ibv_pd                           *pd;
};

/* NVMe RDMA qpair extensions for spdk_nvme_qpair */
struct nvme_rdma_qpair {
        struct spdk_nvme_qpair                  qpair;

        struct rdma_cm_id                       *cm_id;

        struct ibv_cq                           *cq;

        struct  spdk_nvme_rdma_req              *rdma_reqs;

        uint32_t                                max_send_sge;

        uint32_t                                max_recv_sge;

        uint16_t                                num_entries;

        /* Parallel arrays of response buffers + response SGLs of size num_entries */
        struct ibv_sge                          *rsp_sgls;
        struct spdk_nvme_cpl                    *rsps;

        struct ibv_recv_wr                      *rsp_recv_wrs;

        /* Memory region describing all rsps for this qpair */
        struct ibv_mr                           *rsp_mr;

        /*
         * Array of num_entries NVMe commands registered as RDMA message buffers.
         * Indexed by rdma_req->id.
         */
        struct spdk_nvmf_cmd                    *cmds;

        /* Memory region describing all cmds for this qpair */
        struct ibv_mr                           *cmd_mr;

        struct spdk_nvme_rdma_mr_map            *mr_map;

        TAILQ_HEAD(, spdk_nvme_rdma_req)        free_reqs;
        TAILQ_HEAD(, spdk_nvme_rdma_req)        outstanding_reqs;

        /* Placed at the end of the struct since it is not used frequently */
        struct rdma_event_channel               *cm_channel;
};

struct spdk_nvme_rdma_req {
        int                                     id;

        struct ibv_send_wr                      send_wr;

        struct nvme_request                     *req;

        struct ibv_sge                          send_sgl[NVME_RDMA_DEFAULT_TX_SGE];

        TAILQ_ENTRY(spdk_nvme_rdma_req)         link;

        bool                                    request_ready_to_put;
};

static const char *rdma_cm_event_str[] = {
        "RDMA_CM_EVENT_ADDR_RESOLVED",
        "RDMA_CM_EVENT_ADDR_ERROR",
        "RDMA_CM_EVENT_ROUTE_RESOLVED",
        "RDMA_CM_EVENT_ROUTE_ERROR",
        "RDMA_CM_EVENT_CONNECT_REQUEST",
        "RDMA_CM_EVENT_CONNECT_RESPONSE",
        "RDMA_CM_EVENT_CONNECT_ERROR",
        "RDMA_CM_EVENT_UNREACHABLE",
        "RDMA_CM_EVENT_REJECTED",
        "RDMA_CM_EVENT_ESTABLISHED",
        "RDMA_CM_EVENT_DISCONNECTED",
        "RDMA_CM_EVENT_DEVICE_REMOVAL",
        "RDMA_CM_EVENT_MULTICAST_JOIN",
        "RDMA_CM_EVENT_MULTICAST_ERROR",
        "RDMA_CM_EVENT_ADDR_CHANGE",
        "RDMA_CM_EVENT_TIMEWAIT_EXIT"
};

static LIST_HEAD(, spdk_nvme_rdma_mr_map) g_rdma_mr_maps = LIST_HEAD_INITIALIZER(&g_rdma_mr_maps);
static pthread_mutex_t g_rdma_mr_maps_mutex = PTHREAD_MUTEX_INITIALIZER;

static int nvme_rdma_qpair_destroy(struct spdk_nvme_qpair *qpair);

static inline struct nvme_rdma_qpair *
nvme_rdma_qpair(struct spdk_nvme_qpair *qpair)
{
        assert(qpair->trtype == SPDK_NVME_TRANSPORT_RDMA);
        return SPDK_CONTAINEROF(qpair, struct nvme_rdma_qpair, qpair);
}

static inline struct nvme_rdma_ctrlr *
nvme_rdma_ctrlr(struct spdk_nvme_ctrlr *ctrlr)
{
        assert(ctrlr->trid.trtype == SPDK_NVME_TRANSPORT_RDMA);
        return SPDK_CONTAINEROF(ctrlr, struct nvme_rdma_ctrlr, ctrlr);
}

static struct spdk_nvme_rdma_req *
nvme_rdma_req_get(struct nvme_rdma_qpair *rqpair)
{
        struct spdk_nvme_rdma_req *rdma_req;

        rdma_req = TAILQ_FIRST(&rqpair->free_reqs);
        if (rdma_req) {
                TAILQ_REMOVE(&rqpair->free_reqs, rdma_req, link);
                TAILQ_INSERT_TAIL(&rqpair->outstanding_reqs, rdma_req, link);
        }

        return rdma_req;
}

static void
nvme_rdma_req_put(struct nvme_rdma_qpair *rqpair, struct spdk_nvme_rdma_req *rdma_req)
{
        rdma_req->request_ready_to_put = false;
        TAILQ_REMOVE(&rqpair->outstanding_reqs, rdma_req, link);
        TAILQ_INSERT_HEAD(&rqpair->free_reqs, rdma_req, link);
}

static void
nvme_rdma_req_complete(struct nvme_request *req,
                       struct spdk_nvme_cpl *rsp)
{
        nvme_complete_request(req->cb_fn, req->cb_arg, req->qpair, req, rsp);
        nvme_free_request(req);
}

static const char *
nvme_rdma_cm_event_str_get(uint32_t event)
{
        if (event < SPDK_COUNTOF(rdma_cm_event_str)) {
                return rdma_cm_event_str[event];
        } else {
                return "Undefined";
        }
}

static struct rdma_cm_event *
nvme_rdma_get_event(struct rdma_event_channel *channel,
                    enum rdma_cm_event_type evt)
{
        struct rdma_cm_event    *event;
        int                     rc;

        rc = rdma_get_cm_event(channel, &event);
        if (rc < 0) {
                SPDK_ERRLOG("Failed to get event from CM event channel. Error %d (%s)\n",
                            errno, spdk_strerror(errno));
                return NULL;
        }

        if (event->event != evt) {
                SPDK_ERRLOG("Expected %s but received %s (%d) from CM event channel (status = %d)\n",
                            nvme_rdma_cm_event_str_get(evt),
                            nvme_rdma_cm_event_str_get(event->event), event->event, event->status);
                rdma_ack_cm_event(event);
                return NULL;
        }

        return event;
}

static int
nvme_rdma_qpair_init(struct nvme_rdma_qpair *rqpair)
{
        int                     rc;
        struct ibv_qp_init_attr attr;
        struct ibv_device_attr  dev_attr;
        struct nvme_rdma_ctrlr  *rctrlr;

        rc = ibv_query_device(rqpair->cm_id->verbs, &dev_attr);
        if (rc != 0) {
                SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
                return -1;
        }

        rqpair->cq = ibv_create_cq(rqpair->cm_id->verbs, rqpair->num_entries * 2, rqpair, NULL, 0);
        if (!rqpair->cq) {
                SPDK_ERRLOG("Unable to create completion queue: errno %d: %s\n", errno, spdk_strerror(errno));
                return -1;
        }

        rctrlr = nvme_rdma_ctrlr(rqpair->qpair.ctrlr);
        if (g_nvme_hooks.get_ibv_pd) {
                rctrlr->pd = g_nvme_hooks.get_ibv_pd(&rctrlr->ctrlr.trid, rqpair->cm_id->verbs);
        } else {
                rctrlr->pd = NULL;
        }

        memset(&attr, 0, sizeof(struct ibv_qp_init_attr));
        attr.qp_type            = IBV_QPT_RC;
        attr.send_cq            = rqpair->cq;
        attr.recv_cq            = rqpair->cq;
        attr.cap.max_send_wr    = rqpair->num_entries; /* SEND operations */
        attr.cap.max_recv_wr    = rqpair->num_entries; /* RECV operations */
        attr.cap.max_send_sge   = spdk_min(NVME_RDMA_DEFAULT_TX_SGE, dev_attr.max_sge);
        attr.cap.max_recv_sge   = spdk_min(NVME_RDMA_DEFAULT_RX_SGE, dev_attr.max_sge);

        rc = rdma_create_qp(rqpair->cm_id, rctrlr->pd, &attr);

        if (rc) {
                SPDK_ERRLOG("rdma_create_qp failed\n");
                return -1;
        }

        /* ibv_create_qp will change the values in attr.cap. Make sure we store the proper value. */
        rqpair->max_send_sge = spdk_min(NVME_RDMA_DEFAULT_TX_SGE, attr.cap.max_send_sge);
        rqpair->max_recv_sge = spdk_min(NVME_RDMA_DEFAULT_RX_SGE, attr.cap.max_recv_sge);

        rctrlr->pd = rqpair->cm_id->qp->pd;

        rqpair->cm_id->context = &rqpair->qpair;

        return 0;
}

#define nvme_rdma_trace_ibv_sge(sg_list) \
        if (sg_list) { \
                SPDK_DEBUGLOG(SPDK_LOG_NVME, "local addr %p length 0x%x lkey 0x%x\n", \
                              (void *)(sg_list)->addr, (sg_list)->length, (sg_list)->lkey); \
        }

static int
nvme_rdma_post_recv(struct nvme_rdma_qpair *rqpair, uint16_t rsp_idx)
{
        struct ibv_recv_wr *wr, *bad_wr = NULL;
        int rc;

        wr = &rqpair->rsp_recv_wrs[rsp_idx];
        nvme_rdma_trace_ibv_sge(wr->sg_list);

        rc = ibv_post_recv(rqpair->cm_id->qp, wr, &bad_wr);
        if (rc) {
                SPDK_ERRLOG("Failure posting rdma recv, rc = 0x%x\n", rc);
        }

        return rc;
}

static void
nvme_rdma_unregister_rsps(struct nvme_rdma_qpair *rqpair)
{
        if (rqpair->rsp_mr && rdma_dereg_mr(rqpair->rsp_mr)) {
                SPDK_ERRLOG("Unable to de-register rsp_mr\n");
        }
        rqpair->rsp_mr = NULL;
}

static void
nvme_rdma_free_rsps(struct nvme_rdma_qpair *rqpair)
{
        free(rqpair->rsps);
        rqpair->rsps = NULL;
        free(rqpair->rsp_sgls);
        rqpair->rsp_sgls = NULL;
        free(rqpair->rsp_recv_wrs);
        rqpair->rsp_recv_wrs = NULL;
}

static int
nvme_rdma_alloc_rsps(struct nvme_rdma_qpair *rqpair)
{
        rqpair->rsps = NULL;
        rqpair->rsp_recv_wrs = NULL;

        rqpair->rsp_sgls = calloc(rqpair->num_entries, sizeof(*rqpair->rsp_sgls));
        if (!rqpair->rsp_sgls) {
                SPDK_ERRLOG("Failed to allocate rsp_sgls\n");
                goto fail;
        }

        rqpair->rsp_recv_wrs = calloc(rqpair->num_entries,
                                      sizeof(*rqpair->rsp_recv_wrs));
        if (!rqpair->rsp_recv_wrs) {
                SPDK_ERRLOG("Failed to allocate rsp_recv_wrs\n");
                goto fail;
        }

        rqpair->rsps = calloc(rqpair->num_entries, sizeof(*rqpair->rsps));
        if (!rqpair->rsps) {
                SPDK_ERRLOG("can not allocate rdma rsps\n");
                goto fail;
        }

        return 0;
fail:
        nvme_rdma_free_rsps(rqpair);
        return -ENOMEM;
}

static int
nvme_rdma_register_rsps(struct nvme_rdma_qpair *rqpair)
{
        int i;

        rqpair->rsp_mr = rdma_reg_msgs(rqpair->cm_id, rqpair->rsps,
                                       rqpair->num_entries * sizeof(*rqpair->rsps));
        if (rqpair->rsp_mr == NULL) {
                SPDK_ERRLOG("Unable to register rsp_mr\n");
                goto fail;
        }

        for (i = 0; i < rqpair->num_entries; i++) {
                struct ibv_sge *rsp_sgl = &rqpair->rsp_sgls[i];

                rsp_sgl->addr = (uint64_t)&rqpair->rsps[i];
                rsp_sgl->length = sizeof(rqpair->rsps[i]);
                rsp_sgl->lkey = rqpair->rsp_mr->lkey;

                rqpair->rsp_recv_wrs[i].wr_id = i;
                rqpair->rsp_recv_wrs[i].next = NULL;
                rqpair->rsp_recv_wrs[i].sg_list = rsp_sgl;
                rqpair->rsp_recv_wrs[i].num_sge = 1;

                if (nvme_rdma_post_recv(rqpair, i)) {
                        SPDK_ERRLOG("Unable to post connection rx desc\n");
                        goto fail;
                }
        }

        return 0;

fail:
        nvme_rdma_unregister_rsps(rqpair);
        return -ENOMEM;
}

static void
nvme_rdma_unregister_reqs(struct nvme_rdma_qpair *rqpair)
{
        if (rqpair->cmd_mr && rdma_dereg_mr(rqpair->cmd_mr)) {
                SPDK_ERRLOG("Unable to de-register cmd_mr\n");
        }
        rqpair->cmd_mr = NULL;
}

static void
nvme_rdma_free_reqs(struct nvme_rdma_qpair *rqpair)
{
        if (!rqpair->rdma_reqs) {
                return;
        }

        free(rqpair->cmds);
        rqpair->cmds = NULL;

        free(rqpair->rdma_reqs);
        rqpair->rdma_reqs = NULL;
}

static int
nvme_rdma_alloc_reqs(struct nvme_rdma_qpair *rqpair)
{
        rqpair->rdma_reqs = calloc(rqpair->num_entries, sizeof(struct spdk_nvme_rdma_req));
        if (rqpair->rdma_reqs == NULL) {
                SPDK_ERRLOG("Failed to allocate rdma_reqs\n");
                goto fail;
        }

        rqpair->cmds = calloc(rqpair->num_entries, sizeof(*rqpair->cmds));
        if (!rqpair->cmds) {
                SPDK_ERRLOG("Failed to allocate RDMA cmds\n");
                goto fail;
        }

        return 0;
fail:
        nvme_rdma_free_reqs(rqpair);
        return -ENOMEM;
}

static int
nvme_rdma_register_reqs(struct nvme_rdma_qpair *rqpair)
{
        int i;

        rqpair->cmd_mr = rdma_reg_msgs(rqpair->cm_id, rqpair->cmds,
                                       rqpair->num_entries * sizeof(*rqpair->cmds));
        if (!rqpair->cmd_mr) {
                SPDK_ERRLOG("Unable to register cmd_mr\n");
                goto fail;
        }

        TAILQ_INIT(&rqpair->free_reqs);
        TAILQ_INIT(&rqpair->outstanding_reqs);
        for (i = 0; i < rqpair->num_entries; i++) {
                struct spdk_nvme_rdma_req       *rdma_req;
                struct spdk_nvmf_cmd            *cmd;

                rdma_req = &rqpair->rdma_reqs[i];
                cmd = &rqpair->cmds[i];

                rdma_req->id = i;

                /* The first RDMA sgl element will always point
                 * at this data structure. Depending on whether
                 * an NVMe-oF SGL is required, the length of
                 * this element may change. */
                rdma_req->send_sgl[0].addr = (uint64_t)cmd;
                rdma_req->send_sgl[0].lkey = rqpair->cmd_mr->lkey;

                rdma_req->send_wr.wr_id = (uint64_t)rdma_req;
                rdma_req->send_wr.next = NULL;
                rdma_req->send_wr.opcode = IBV_WR_SEND;
                rdma_req->send_wr.send_flags = IBV_SEND_SIGNALED;
                rdma_req->send_wr.sg_list = rdma_req->send_sgl;
                rdma_req->send_wr.imm_data = 0;

                TAILQ_INSERT_TAIL(&rqpair->free_reqs, rdma_req, link);
        }

        return 0;

fail:
        nvme_rdma_unregister_reqs(rqpair);
        return -ENOMEM;
}

static int
nvme_rdma_recv(struct nvme_rdma_qpair *rqpair, uint64_t rsp_idx)
{
        struct spdk_nvme_qpair *qpair = &rqpair->qpair;
        struct spdk_nvme_rdma_req *rdma_req;
        struct spdk_nvme_cpl *rsp;
        struct nvme_request *req;

        assert(rsp_idx < rqpair->num_entries);
        rsp = &rqpair->rsps[rsp_idx];
        rdma_req = &rqpair->rdma_reqs[rsp->cid];

        req = rdma_req->req;
        nvme_rdma_req_complete(req, rsp);

        if (rdma_req->request_ready_to_put) {
                nvme_rdma_req_put(rqpair, rdma_req);
        } else {
                rdma_req->request_ready_to_put = true;
        }

        if (nvme_rdma_post_recv(rqpair, rsp_idx)) {
                SPDK_ERRLOG("Unable to re-post rx descriptor\n");
                return -1;
        }

        if (!STAILQ_EMPTY(&qpair->queued_req) && !qpair->ctrlr->is_resetting) {
                req = STAILQ_FIRST(&qpair->queued_req);
                STAILQ_REMOVE_HEAD(&qpair->queued_req, stailq);
                nvme_qpair_submit_request(qpair, req);
        }

        return 0;
}

static int
nvme_rdma_resolve_addr(struct nvme_rdma_qpair *rqpair,
                       struct sockaddr *src_addr,
                       struct sockaddr *dst_addr,
                       struct rdma_event_channel *cm_channel)
{
        int ret;
        struct rdma_cm_event *event;

        ret = rdma_resolve_addr(rqpair->cm_id, src_addr, dst_addr,
                                NVME_RDMA_TIME_OUT_IN_MS);
        if (ret) {
                SPDK_ERRLOG("rdma_resolve_addr, %d\n", errno);
                return ret;
        }

        event = nvme_rdma_get_event(cm_channel, RDMA_CM_EVENT_ADDR_RESOLVED);
        if (event == NULL) {
                SPDK_ERRLOG("RDMA address resolution error\n");
                return -1;
        }
        rdma_ack_cm_event(event);

        ret = rdma_resolve_route(rqpair->cm_id, NVME_RDMA_TIME_OUT_IN_MS);
        if (ret) {
                SPDK_ERRLOG("rdma_resolve_route\n");
                return ret;
        }

        event = nvme_rdma_get_event(cm_channel, RDMA_CM_EVENT_ROUTE_RESOLVED);
        if (event == NULL) {
                SPDK_ERRLOG("RDMA route resolution error\n");
                return -1;
        }
        rdma_ack_cm_event(event);

        return 0;
}

static int
nvme_rdma_connect(struct nvme_rdma_qpair *rqpair)
{
        struct rdma_conn_param                          param = {};
        struct spdk_nvmf_rdma_request_private_data      request_data = {};
        struct spdk_nvmf_rdma_accept_private_data       *accept_data;
        struct ibv_device_attr                          attr;
        int                                             ret;
        struct rdma_cm_event                            *event;
        struct spdk_nvme_ctrlr                          *ctrlr;

        ret = ibv_query_device(rqpair->cm_id->verbs, &attr);
        if (ret != 0) {
                SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
                return ret;
        }

        param.responder_resources = spdk_min(rqpair->num_entries, attr.max_qp_rd_atom);

        ctrlr = rqpair->qpair.ctrlr;
        if (!ctrlr) {
                return -1;
        }

        request_data.qid = rqpair->qpair.id;
        request_data.hrqsize = rqpair->num_entries;
        request_data.hsqsize = rqpair->num_entries - 1;
        request_data.cntlid = ctrlr->cntlid;

        param.private_data = &request_data;
        param.private_data_len = sizeof(request_data);
        param.retry_count = 7;
        param.rnr_retry_count = 7;

        ret = rdma_connect(rqpair->cm_id, &param);
        if (ret) {
                SPDK_ERRLOG("nvme rdma connect error\n");
                return ret;
        }

        event = nvme_rdma_get_event(rqpair->cm_channel, RDMA_CM_EVENT_ESTABLISHED);
        if (event == NULL) {
                SPDK_ERRLOG("RDMA connect error\n");
                return -1;
        }

        accept_data = (struct spdk_nvmf_rdma_accept_private_data *)event->param.conn.private_data;
        if (accept_data == NULL) {
                rdma_ack_cm_event(event);
                SPDK_ERRLOG("NVMe-oF target did not return accept data\n");
                return -1;
        }

        SPDK_DEBUGLOG(SPDK_LOG_NVME, "Requested queue depth %d. Actually got queue depth %d.\n",
                      rqpair->num_entries, accept_data->crqsize);

        rqpair->num_entries = spdk_min(rqpair->num_entries, accept_data->crqsize);

        rdma_ack_cm_event(event);

        return 0;
}

static int
nvme_rdma_parse_addr(struct sockaddr_storage *sa, int family, const char *addr, const char *service)
{
        struct addrinfo *res;
        struct addrinfo hints;
        int ret;

        memset(&hints, 0, sizeof(hints));
        hints.ai_family = family;
        hints.ai_socktype = SOCK_STREAM;
        hints.ai_protocol = 0;

        ret = getaddrinfo(addr, service, &hints, &res);
        if (ret) {
                SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(ret), ret);
                return ret;
        }

        if (res->ai_addrlen > sizeof(*sa)) {
                SPDK_ERRLOG("getaddrinfo() ai_addrlen %zu too large\n", (size_t)res->ai_addrlen);
                ret = EINVAL;
        } else {
                memcpy(sa, res->ai_addr, res->ai_addrlen);
        }

        freeaddrinfo(res);
        return ret;
}

static int
nvme_rdma_mr_map_notify(void *cb_ctx, struct spdk_mem_map *map,
                        enum spdk_mem_map_notify_action action,
                        void *vaddr, size_t size)
{
        struct ibv_pd *pd = cb_ctx;
        struct ibv_mr *mr;
        int rc;

        switch (action) {
        case SPDK_MEM_MAP_NOTIFY_REGISTER:
                if (!g_nvme_hooks.get_rkey) {
                        mr = ibv_reg_mr(pd, vaddr, size,
                                        IBV_ACCESS_LOCAL_WRITE |
                                        IBV_ACCESS_REMOTE_READ |
                                        IBV_ACCESS_REMOTE_WRITE);
                        if (mr == NULL) {
                                SPDK_ERRLOG("ibv_reg_mr() failed\n");
                                return -EFAULT;
                        } else {
                                rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
                        }
                } else {
                        rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
                                                          g_nvme_hooks.get_rkey(pd, vaddr, size));
                }
                break;
        case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
                if (!g_nvme_hooks.get_rkey) {
                        mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
                        if (mr) {
                                ibv_dereg_mr(mr);
                        }
                }
                rc = spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
                break;
        default:
                SPDK_UNREACHABLE();
        }

        return rc;
}

static int
nvme_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
{
        /* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
        return addr_1 == addr_2;
}

static int
nvme_rdma_register_mem(struct nvme_rdma_qpair *rqpair)
{
        struct ibv_pd *pd = rqpair->cm_id->qp->pd;
        struct spdk_nvme_rdma_mr_map *mr_map;
        const struct spdk_mem_map_ops nvme_rdma_map_ops = {
                .notify_cb = nvme_rdma_mr_map_notify,
                .are_contiguous = nvme_rdma_check_contiguous_entries
        };

        pthread_mutex_lock(&g_rdma_mr_maps_mutex);

        /* Look up existing mem map registration for this pd */
        LIST_FOREACH(mr_map, &g_rdma_mr_maps, link) {
                if (mr_map->pd == pd) {
                        mr_map->ref++;
                        rqpair->mr_map = mr_map;
                        pthread_mutex_unlock(&g_rdma_mr_maps_mutex);
                        return 0;
                }
        }

        mr_map = calloc(1, sizeof(*mr_map));
        if (mr_map == NULL) {
                SPDK_ERRLOG("calloc() failed\n");
                pthread_mutex_unlock(&g_rdma_mr_maps_mutex);
                return -1;
        }

        mr_map->ref = 1;
        mr_map->pd = pd;
        mr_map->map = spdk_mem_map_alloc((uint64_t)NULL, &nvme_rdma_map_ops, pd);
        if (mr_map->map == NULL) {
                SPDK_ERRLOG("spdk_mem_map_alloc() failed\n");
                free(mr_map);
                pthread_mutex_unlock(&g_rdma_mr_maps_mutex);
                return -1;
        }

        rqpair->mr_map = mr_map;
        LIST_INSERT_HEAD(&g_rdma_mr_maps, mr_map, link);

        pthread_mutex_unlock(&g_rdma_mr_maps_mutex);

        return 0;
}

static void
nvme_rdma_unregister_mem(struct nvme_rdma_qpair *rqpair)
{
        struct spdk_nvme_rdma_mr_map *mr_map;

        mr_map = rqpair->mr_map;
        rqpair->mr_map = NULL;

        if (mr_map == NULL) {
                return;
        }

        pthread_mutex_lock(&g_rdma_mr_maps_mutex);

        assert(mr_map->ref > 0);
        mr_map->ref--;
        if (mr_map->ref == 0) {
                LIST_REMOVE(mr_map, link);
                spdk_mem_map_free(&mr_map->map);
                free(mr_map);
        }

        pthread_mutex_unlock(&g_rdma_mr_maps_mutex);
}

static int
nvme_rdma_qpair_connect(struct nvme_rdma_qpair *rqpair)
{
        struct sockaddr_storage dst_addr;
        struct sockaddr_storage src_addr;
        bool src_addr_specified;
        int rc;
        struct spdk_nvme_ctrlr *ctrlr;
        int family;

        rqpair->cm_channel = rdma_create_event_channel();
        if (rqpair->cm_channel == NULL) {
                SPDK_ERRLOG("rdma_create_event_channel() failed\n");
                return -1;
        }

        ctrlr = rqpair->qpair.ctrlr;

        switch (ctrlr->trid.adrfam) {
        case SPDK_NVMF_ADRFAM_IPV4:
                family = AF_INET;
                break;
        case SPDK_NVMF_ADRFAM_IPV6:
                family = AF_INET6;
                break;
        default:
                SPDK_ERRLOG("Unhandled ADRFAM %d\n", ctrlr->trid.adrfam);
                return -1;
        }

        SPDK_DEBUGLOG(SPDK_LOG_NVME, "adrfam %d ai_family %d\n", ctrlr->trid.adrfam, family);

        memset(&dst_addr, 0, sizeof(dst_addr));

        SPDK_DEBUGLOG(SPDK_LOG_NVME, "trsvcid is %s\n", ctrlr->trid.trsvcid);
        rc = nvme_rdma_parse_addr(&dst_addr, family, ctrlr->trid.traddr, ctrlr->trid.trsvcid);
        if (rc != 0) {
                SPDK_ERRLOG("dst_addr nvme_rdma_parse_addr() failed\n");
                return -1;
        }

        if (ctrlr->opts.src_addr[0] || ctrlr->opts.src_svcid[0]) {
                memset(&src_addr, 0, sizeof(src_addr));
                rc = nvme_rdma_parse_addr(&src_addr, family, ctrlr->opts.src_addr, ctrlr->opts.src_svcid);
                if (rc != 0) {
                        SPDK_ERRLOG("src_addr nvme_rdma_parse_addr() failed\n");
                        return -1;
                }
                src_addr_specified = true;
        } else {
                src_addr_specified = false;
        }

        rc = rdma_create_id(rqpair->cm_channel, &rqpair->cm_id, rqpair, RDMA_PS_TCP);
        if (rc < 0) {
                SPDK_ERRLOG("rdma_create_id() failed\n");
                return -1;
        }

        rc = nvme_rdma_resolve_addr(rqpair,
                                    src_addr_specified ? (struct sockaddr *)&src_addr : NULL,
                                    (struct sockaddr *)&dst_addr, rqpair->cm_channel);
        if (rc < 0) {
                SPDK_ERRLOG("nvme_rdma_resolve_addr() failed\n");
                return -1;
        }

        rc = nvme_rdma_qpair_init(rqpair);
        if (rc < 0) {
                SPDK_ERRLOG("nvme_rdma_qpair_init() failed\n");
                return -1;
        }

        rc = nvme_rdma_connect(rqpair);
        if (rc != 0) {
                SPDK_ERRLOG("Unable to connect the rqpair\n");
                return -1;
        }

        rc = nvme_rdma_register_reqs(rqpair);
        SPDK_DEBUGLOG(SPDK_LOG_NVME, "rc =%d\n", rc);
        if (rc) {
                SPDK_ERRLOG("Unable to register rqpair RDMA requests\n");
                return -1;
        }
        SPDK_DEBUGLOG(SPDK_LOG_NVME, "RDMA requests registered\n");

        rc = nvme_rdma_register_rsps(rqpair);
        SPDK_DEBUGLOG(SPDK_LOG_NVME, "rc =%d\n", rc);
        if (rc < 0) {
                SPDK_ERRLOG("Unable to register rqpair RDMA responses\n");
                return -1;
        }
        SPDK_DEBUGLOG(SPDK_LOG_NVME, "RDMA responses registered\n");

        rc = nvme_rdma_register_mem(rqpair);
        if (rc < 0) {
                SPDK_ERRLOG("Unable to register memory for RDMA\n");
                return -1;
        }

        rc = nvme_fabric_qpair_connect(&rqpair->qpair, rqpair->num_entries);
        if (rc < 0) {
                SPDK_ERRLOG("Failed to send an NVMe-oF Fabric CONNECT command\n");
                return -1;
        }

        return 0;
}

/*
 * Build SGL describing empty payload.
 */
static int
nvme_rdma_build_null_request(struct spdk_nvme_rdma_req *rdma_req)
{
        struct nvme_request *req = rdma_req->req;

        req->cmd.psdt = SPDK_NVME_PSDT_SGL_MPTR_CONTIG;

        /* The first element of this SGL is pointing at an
         * spdk_nvmf_cmd object. For this particular command,
         * we only need the first 64 bytes corresponding to
         * the NVMe command. */
        rdma_req->send_sgl[0].length = sizeof(struct spdk_nvme_cmd);

        /* The RDMA SGL needs one element describing the NVMe command. */
        rdma_req->send_wr.num_sge = 1;

        req->cmd.dptr.sgl1.keyed.type = SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK;
        req->cmd.dptr.sgl1.keyed.subtype = SPDK_NVME_SGL_SUBTYPE_ADDRESS;
        req->cmd.dptr.sgl1.keyed.length = 0;
        req->cmd.dptr.sgl1.keyed.key = 0;
        req->cmd.dptr.sgl1.address = 0;

        return 0;
}

/*
 * Build inline SGL describing contiguous payload buffer.
 */
static int
nvme_rdma_build_contig_inline_request(struct nvme_rdma_qpair *rqpair,
                                      struct spdk_nvme_rdma_req *rdma_req)
{
        struct nvme_request *req = rdma_req->req;
        struct ibv_mr *mr;
        void *payload;
        uint64_t requested_size;

        payload = req->payload.contig_or_cb_arg + req->payload_offset;
        assert(req->payload_size != 0);
        assert(nvme_payload_type(&req->payload) == NVME_PAYLOAD_TYPE_CONTIG);

        requested_size = req->payload_size;

        if (!g_nvme_hooks.get_rkey) {
                mr = (struct ibv_mr *)spdk_mem_map_translate(rqpair->mr_map->map,
                                (uint64_t)payload, &requested_size);

                if (mr == NULL || requested_size < req->payload_size) {
                        if (mr) {
                                SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions\n");
                        }
                        return -EINVAL;
                }
                rdma_req->send_sgl[1].lkey = mr->lkey;
        } else {
                rdma_req->send_sgl[1].lkey = spdk_mem_map_translate(rqpair->mr_map->map,
                                             (uint64_t)payload,
                                             &requested_size);

        }

        /* The first element of this SGL is pointing at an
         * spdk_nvmf_cmd object. For this particular command,
         * we only need the first 64 bytes corresponding to
         * the NVMe command. */
        rdma_req->send_sgl[0].length = sizeof(struct spdk_nvme_cmd);

        rdma_req->send_sgl[1].addr = (uint64_t)payload;
        rdma_req->send_sgl[1].length = (uint32_t)req->payload_size;

        /* The RDMA SGL contains two elements. The first describes
         * the NVMe command and the second describes the data
         * payload. */
        rdma_req->send_wr.num_sge = 2;

        req->cmd.psdt = SPDK_NVME_PSDT_SGL_MPTR_CONTIG;
        req->cmd.dptr.sgl1.unkeyed.type = SPDK_NVME_SGL_TYPE_DATA_BLOCK;
        req->cmd.dptr.sgl1.unkeyed.subtype = SPDK_NVME_SGL_SUBTYPE_OFFSET;
        req->cmd.dptr.sgl1.unkeyed.length = (uint32_t)req->payload_size;
        /* Inline only supported for icdoff == 0 currently.  This function will
         * not get called for controllers with other values. */
        req->cmd.dptr.sgl1.address = (uint64_t)0;

        return 0;
}

/*
 * Build SGL describing contiguous payload buffer.
 */
static int
nvme_rdma_build_contig_request(struct nvme_rdma_qpair *rqpair,
                               struct spdk_nvme_rdma_req *rdma_req)
{
        struct nvme_request *req = rdma_req->req;
        void *payload = req->payload.contig_or_cb_arg + req->payload_offset;
        struct ibv_mr *mr;
        uint64_t requested_size;

        assert(req->payload_size != 0);
        assert(nvme_payload_type(&req->payload) == NVME_PAYLOAD_TYPE_CONTIG);

        requested_size = req->payload_size;
        if (!g_nvme_hooks.get_rkey) {

                mr = (struct ibv_mr *)spdk_mem_map_translate(rqpair->mr_map->map, (uint64_t)payload,
                                &requested_size);
                if (mr == NULL) {
                        return -1;
                }
                req->cmd.dptr.sgl1.keyed.key = mr->rkey;
        } else {
                req->cmd.dptr.sgl1.keyed.key = spdk_mem_map_translate(rqpair->mr_map->map,
                                               (uint64_t)payload,
                                               &requested_size);
        }

        if (requested_size < req->payload_size) {
                SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions\n");
                return -1;
        }

        /* The first element of this SGL is pointing at an
         * spdk_nvmf_cmd object. For this particular command,
         * we only need the first 64 bytes corresponding to
         * the NVMe command. */
        rdma_req->send_sgl[0].length = sizeof(struct spdk_nvme_cmd);

        /* The RDMA SGL needs one element describing the NVMe command. */
        rdma_req->send_wr.num_sge = 1;

        req->cmd.psdt = SPDK_NVME_PSDT_SGL_MPTR_CONTIG;
        req->cmd.dptr.sgl1.keyed.type = SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK;
        req->cmd.dptr.sgl1.keyed.subtype = SPDK_NVME_SGL_SUBTYPE_ADDRESS;
        req->cmd.dptr.sgl1.keyed.length = req->payload_size;
        req->cmd.dptr.sgl1.address = (uint64_t)payload;

        return 0;
}

/*
 * Build SGL describing scattered payload buffer.
 */
static int
nvme_rdma_build_sgl_request(struct nvme_rdma_qpair *rqpair,
                            struct spdk_nvme_rdma_req *rdma_req)
{
        struct nvme_request *req = rdma_req->req;
        struct spdk_nvmf_cmd *cmd = &rqpair->cmds[rdma_req->id];
        struct ibv_mr *mr = NULL;
        void *virt_addr;
        uint64_t remaining_size, mr_length;
        uint32_t sge_length;
        int rc, max_num_sgl, num_sgl_desc;

        assert(req->payload_size != 0);
        assert(nvme_payload_type(&req->payload) == NVME_PAYLOAD_TYPE_SGL);
        assert(req->payload.reset_sgl_fn != NULL);
        assert(req->payload.next_sge_fn != NULL);
        req->payload.reset_sgl_fn(req->payload.contig_or_cb_arg, req->payload_offset);

        max_num_sgl = req->qpair->ctrlr->max_sges;

        remaining_size = req->payload_size;
        num_sgl_desc = 0;
        do {
                rc = req->payload.next_sge_fn(req->payload.contig_or_cb_arg, &virt_addr, &sge_length);
                if (rc) {
                        return -1;
                }

                sge_length = spdk_min(remaining_size, sge_length);
                mr_length = sge_length;

                if (!g_nvme_hooks.get_rkey) {
                        mr = (struct ibv_mr *)spdk_mem_map_translate(rqpair->mr_map->map,
                                        (uint64_t)virt_addr,
                                        &mr_length);
                        if (mr == NULL) {
                                return -1;
                        }
                        cmd->sgl[num_sgl_desc].keyed.key = mr->rkey;
                } else {
                        cmd->sgl[num_sgl_desc].keyed.key = spdk_mem_map_translate(rqpair->mr_map->map,
                                                           (uint64_t)virt_addr,
                                                           &mr_length);
                }

                if (mr_length < sge_length) {
                        SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions\n");
                        return -1;
                }

                cmd->sgl[num_sgl_desc].keyed.type = SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK;
                cmd->sgl[num_sgl_desc].keyed.subtype = SPDK_NVME_SGL_SUBTYPE_ADDRESS;
                cmd->sgl[num_sgl_desc].keyed.length = sge_length;
                cmd->sgl[num_sgl_desc].address = (uint64_t)virt_addr;

                remaining_size -= sge_length;
                num_sgl_desc++;
        } while (remaining_size > 0 && num_sgl_desc < max_num_sgl);


        /* Should be impossible if we did our sgl checks properly up the stack, but do a sanity check here. */
        if (remaining_size > 0) {
                return -1;
        }

        req->cmd.psdt = SPDK_NVME_PSDT_SGL_MPTR_CONTIG;

        /* The RDMA SGL needs one element describing some portion
         * of the spdk_nvmf_cmd structure. */
        rdma_req->send_wr.num_sge = 1;

        /*
         * If only one SGL descriptor is required, it can be embedded directly in the command
         * as a data block descriptor.
         */
        if (num_sgl_desc == 1) {
                /* The first element of this SGL is pointing at an
                 * spdk_nvmf_cmd object. For this particular command,
                 * we only need the first 64 bytes corresponding to
                 * the NVMe command. */
                rdma_req->send_sgl[0].length = sizeof(struct spdk_nvme_cmd);

                req->cmd.dptr.sgl1.keyed.type = cmd->sgl[0].keyed.type;
                req->cmd.dptr.sgl1.keyed.subtype = cmd->sgl[0].keyed.subtype;
                req->cmd.dptr.sgl1.keyed.length = cmd->sgl[0].keyed.length;
                req->cmd.dptr.sgl1.keyed.key = cmd->sgl[0].keyed.key;
                req->cmd.dptr.sgl1.address = cmd->sgl[0].address;
        } else {
                /*
                 * Otherwise, The SGL descriptor embedded in the command must point to the list of
                 * SGL descriptors used to describe the operation. In that case it is a last segment descriptor.
                 */
                rdma_req->send_sgl[0].length = sizeof(struct spdk_nvme_cmd) + sizeof(struct
                                               spdk_nvme_sgl_descriptor) * num_sgl_desc;

                req->cmd.dptr.sgl1.unkeyed.type = SPDK_NVME_SGL_TYPE_LAST_SEGMENT;
                req->cmd.dptr.sgl1.unkeyed.subtype = SPDK_NVME_SGL_SUBTYPE_OFFSET;
                req->cmd.dptr.sgl1.unkeyed.length = num_sgl_desc * sizeof(struct spdk_nvme_sgl_descriptor);
                req->cmd.dptr.sgl1.address = (uint64_t)0;
        }

        return 0;
}

/*
 * Build inline SGL describing sgl payload buffer.
 */
static int
nvme_rdma_build_sgl_inline_request(struct nvme_rdma_qpair *rqpair,
                                   struct spdk_nvme_rdma_req *rdma_req)
{
        struct nvme_request *req = rdma_req->req;
        struct ibv_mr *mr;
        uint32_t length;
        uint64_t requested_size;
        void *virt_addr;
        int rc, i;

        assert(req->payload_size != 0);
        assert(nvme_payload_type(&req->payload) == NVME_PAYLOAD_TYPE_SGL);
        assert(req->payload.reset_sgl_fn != NULL);
        assert(req->payload.next_sge_fn != NULL);
        req->payload.reset_sgl_fn(req->payload.contig_or_cb_arg, req->payload_offset);

        rc = req->payload.next_sge_fn(req->payload.contig_or_cb_arg, &virt_addr, &length);
        if (rc) {
                return -1;
        }

        if (length < req->payload_size) {
                SPDK_DEBUGLOG(SPDK_LOG_NVME, "Inline SGL request split so sending separately.\n");
                return nvme_rdma_build_sgl_request(rqpair, rdma_req);
        }

        if (length > req->payload_size) {
                length = req->payload_size;
        }

        requested_size = length;
        mr = (struct ibv_mr *)spdk_mem_map_translate(rqpair->mr_map->map, (uint64_t)virt_addr,
                        &requested_size);
        if (mr == NULL || requested_size < length) {
                for (i = 1; i < rdma_req->send_wr.num_sge; i++) {
                        rdma_req->send_sgl[i].addr = 0;
                        rdma_req->send_sgl[i].length = 0;
                        rdma_req->send_sgl[i].lkey = 0;
                }

                if (mr) {
                        SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions\n");
                }
                return -1;
        }

        rdma_req->send_sgl[1].addr = (uint64_t)virt_addr;
        rdma_req->send_sgl[1].length = length;
        rdma_req->send_sgl[1].lkey = mr->lkey;

        rdma_req->send_wr.num_sge = 2;

        /* The first element of this SGL is pointing at an
         * spdk_nvmf_cmd object. For this particular command,
         * we only need the first 64 bytes corresponding to
         * the NVMe command. */
        rdma_req->send_sgl[0].length = sizeof(struct spdk_nvme_cmd);

        req->cmd.psdt = SPDK_NVME_PSDT_SGL_MPTR_CONTIG;
        req->cmd.dptr.sgl1.unkeyed.type = SPDK_NVME_SGL_TYPE_DATA_BLOCK;
        req->cmd.dptr.sgl1.unkeyed.subtype = SPDK_NVME_SGL_SUBTYPE_OFFSET;
        req->cmd.dptr.sgl1.unkeyed.length = (uint32_t)req->payload_size;
        /* Inline only supported for icdoff == 0 currently.  This function will
         * not get called for controllers with other values. */
        req->cmd.dptr.sgl1.address = (uint64_t)0;

        return 0;
}

static inline unsigned int
nvme_rdma_icdsz_bytes(struct spdk_nvme_ctrlr *ctrlr)
{
        return (ctrlr->cdata.nvmf_specific.ioccsz * 16 - sizeof(struct spdk_nvme_cmd));
}

static int
nvme_rdma_req_init(struct nvme_rdma_qpair *rqpair, struct nvme_request *req,
                   struct spdk_nvme_rdma_req *rdma_req)
{
        struct spdk_nvme_ctrlr *ctrlr = rqpair->qpair.ctrlr;
        int rc;

        rdma_req->req = req;
        req->cmd.cid = rdma_req->id;

        if (req->payload_size == 0) {
                rc = nvme_rdma_build_null_request(rdma_req);
        } else if (nvme_payload_type(&req->payload) == NVME_PAYLOAD_TYPE_CONTIG) {
                /*
                 * Check if icdoff is non zero, to avoid interop conflicts with
                 * targets with non-zero icdoff.  Both SPDK and the Linux kernel
                 * targets use icdoff = 0.  For targets with non-zero icdoff, we
                 * will currently just not use inline data for now.
                 */
                if (req->cmd.opc == SPDK_NVME_OPC_WRITE &&
                    req->payload_size <= nvme_rdma_icdsz_bytes(ctrlr) &&
                    (ctrlr->cdata.nvmf_specific.icdoff == 0)) {
                        rc = nvme_rdma_build_contig_inline_request(rqpair, rdma_req);
                } else {
                        rc = nvme_rdma_build_contig_request(rqpair, rdma_req);
                }
        } else if (nvme_payload_type(&req->payload) == NVME_PAYLOAD_TYPE_SGL) {
                if (req->cmd.opc == SPDK_NVME_OPC_WRITE &&
                    req->payload_size <= nvme_rdma_icdsz_bytes(ctrlr) &&
                    ctrlr->cdata.nvmf_specific.icdoff == 0) {
                        rc = nvme_rdma_build_sgl_inline_request(rqpair, rdma_req);
                } else {
                        rc = nvme_rdma_build_sgl_request(rqpair, rdma_req);
                }
        } else {
                rc = -1;
        }

        if (rc) {
                return rc;
        }

        memcpy(&rqpair->cmds[rdma_req->id], &req->cmd, sizeof(req->cmd));
        return 0;
}

static struct spdk_nvme_qpair *
nvme_rdma_ctrlr_create_qpair(struct spdk_nvme_ctrlr *ctrlr,
                             uint16_t qid, uint32_t qsize,
                             enum spdk_nvme_qprio qprio,
                             uint32_t num_requests)
{
        struct nvme_rdma_qpair *rqpair;
        struct spdk_nvme_qpair *qpair;
        int rc;

        rqpair = calloc(1, sizeof(struct nvme_rdma_qpair));
        if (!rqpair) {
                SPDK_ERRLOG("failed to get create rqpair\n");
                return NULL;
        }

        rqpair->num_entries = qsize;

        qpair = &rqpair->qpair;

        rc = nvme_qpair_init(qpair, qid, ctrlr, qprio, num_requests);
        if (rc != 0) {
                return NULL;
        }

        rc = nvme_rdma_alloc_reqs(rqpair);
        SPDK_DEBUGLOG(SPDK_LOG_NVME, "rc =%d\n", rc);
        if (rc) {
                SPDK_ERRLOG("Unable to allocate rqpair RDMA requests\n");
                return NULL;
        }
        SPDK_DEBUGLOG(SPDK_LOG_NVME, "RDMA requests allocated\n");

        rc = nvme_rdma_alloc_rsps(rqpair);
        SPDK_DEBUGLOG(SPDK_LOG_NVME, "rc =%d\n", rc);
        if (rc < 0) {
                SPDK_ERRLOG("Unable to allocate rqpair RDMA responses\n");
                return NULL;
        }
        SPDK_DEBUGLOG(SPDK_LOG_NVME, "RDMA responses allocated\n");

        rc = nvme_rdma_qpair_connect(rqpair);
        if (rc < 0) {
                nvme_rdma_qpair_destroy(qpair);
                return NULL;
        }

        return qpair;
}

static void
nvme_rdma_qpair_disconnect(struct spdk_nvme_qpair *qpair)
{
        struct nvme_rdma_qpair *rqpair = nvme_rdma_qpair(qpair);

        nvme_rdma_unregister_mem(rqpair);
        nvme_rdma_unregister_reqs(rqpair);
        nvme_rdma_unregister_rsps(rqpair);

        if (rqpair->cm_id) {
                if (rqpair->cm_id->qp) {
                        rdma_destroy_qp(rqpair->cm_id);
                }
                rdma_destroy_id(rqpair->cm_id);
        }

        if (rqpair->cq) {
                ibv_destroy_cq(rqpair->cq);
        }

        if (rqpair->cm_channel) {
                rdma_destroy_event_channel(rqpair->cm_channel);
        }
}

static int
nvme_rdma_qpair_destroy(struct spdk_nvme_qpair *qpair)
{
        struct nvme_rdma_qpair *rqpair;

        if (!qpair) {
                return -1;
        }
        nvme_rdma_qpair_disconnect(qpair);
        nvme_rdma_qpair_abort_reqs(qpair, 1);
        nvme_qpair_deinit(qpair);

        rqpair = nvme_rdma_qpair(qpair);

        nvme_rdma_free_reqs(rqpair);
        nvme_rdma_free_rsps(rqpair);
        free(rqpair);

        return 0;
}

struct spdk_nvme_qpair *
nvme_rdma_ctrlr_create_io_qpair(struct spdk_nvme_ctrlr *ctrlr, uint16_t qid,
                                const struct spdk_nvme_io_qpair_opts *opts)
{
        return nvme_rdma_ctrlr_create_qpair(ctrlr, qid, opts->io_queue_size, opts->qprio,
                                            opts->io_queue_requests);
}

int
nvme_rdma_ctrlr_enable(struct spdk_nvme_ctrlr *ctrlr)
{
        /* do nothing here */
        return 0;
}

/* This function must only be called while holding g_spdk_nvme_driver->lock */
int
nvme_rdma_ctrlr_scan(struct spdk_nvme_probe_ctx *probe_ctx,
                     bool direct_connect)
{
        struct spdk_nvme_ctrlr_opts discovery_opts;
        struct spdk_nvme_ctrlr *discovery_ctrlr;
        union spdk_nvme_cc_register cc;
        int rc;
        struct nvme_completion_poll_status status;

        if (strcmp(probe_ctx->trid.subnqn, SPDK_NVMF_DISCOVERY_NQN) != 0) {
                /* It is not a discovery_ctrlr info and try to directly connect it */
                rc = nvme_ctrlr_probe(&probe_ctx->trid, probe_ctx, NULL);
                return rc;
        }

        spdk_nvme_ctrlr_get_default_ctrlr_opts(&discovery_opts, sizeof(discovery_opts));
        /* For discovery_ctrlr set the timeout to 0 */
        discovery_opts.keep_alive_timeout_ms = 0;

        discovery_ctrlr = nvme_rdma_ctrlr_construct(&probe_ctx->trid, &discovery_opts, NULL);
        if (discovery_ctrlr == NULL) {
                return -1;
        }

        /* TODO: this should be using the normal NVMe controller initialization process */
        cc.raw = 0;
        cc.bits.en = 1;
        cc.bits.iosqes = 6; /* SQ entry size == 64 == 2^6 */
        cc.bits.iocqes = 4; /* CQ entry size == 16 == 2^4 */
        rc = nvme_transport_ctrlr_set_reg_4(discovery_ctrlr, offsetof(struct spdk_nvme_registers, cc.raw),
                                            cc.raw);
        if (rc < 0) {
                SPDK_ERRLOG("Failed to set cc\n");
                nvme_ctrlr_destruct(discovery_ctrlr);
                return -1;
        }

        /* Direct attach through spdk_nvme_connect() API */
        if (direct_connect == true) {
                /* get the cdata info */
                rc = nvme_ctrlr_cmd_identify(discovery_ctrlr, SPDK_NVME_IDENTIFY_CTRLR, 0, 0,
                                             &discovery_ctrlr->cdata, sizeof(discovery_ctrlr->cdata),
                                             nvme_completion_poll_cb, &status);
                if (rc != 0) {
                        SPDK_ERRLOG("Failed to identify cdata\n");
                        return rc;
                }

                if (spdk_nvme_wait_for_completion(discovery_ctrlr->adminq, &status)) {
                        SPDK_ERRLOG("nvme_identify_controller failed!\n");
                        return -ENXIO;
                }

                /* Set the ready state to skip the normal init process */
                discovery_ctrlr->state = NVME_CTRLR_STATE_READY;
                nvme_ctrlr_connected(probe_ctx, discovery_ctrlr);
                nvme_ctrlr_add_process(discovery_ctrlr, 0);
                return 0;
        }

        rc = nvme_fabric_ctrlr_discover(discovery_ctrlr, probe_ctx);
        nvme_ctrlr_destruct(discovery_ctrlr);
        return rc;
}

struct spdk_nvme_ctrlr *nvme_rdma_ctrlr_construct(const struct spdk_nvme_transport_id *trid,
                const struct spdk_nvme_ctrlr_opts *opts,
                void *devhandle)
{
        struct nvme_rdma_ctrlr *rctrlr;
        union spdk_nvme_cap_register cap;
        union spdk_nvme_vs_register vs;
        int rc;

        rctrlr = calloc(1, sizeof(struct nvme_rdma_ctrlr));
        if (rctrlr == NULL) {
                SPDK_ERRLOG("could not allocate ctrlr\n");
                return NULL;
        }

        rctrlr->ctrlr.trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
        rctrlr->ctrlr.opts = *opts;
        memcpy(&rctrlr->ctrlr.trid, trid, sizeof(rctrlr->ctrlr.trid));

        rc = nvme_ctrlr_construct(&rctrlr->ctrlr);
        if (rc != 0) {
                free(rctrlr);
                return NULL;
        }

        rctrlr->ctrlr.adminq = nvme_rdma_ctrlr_create_qpair(&rctrlr->ctrlr, 0,
                               SPDK_NVMF_MIN_ADMIN_QUEUE_ENTRIES, 0, SPDK_NVMF_MIN_ADMIN_QUEUE_ENTRIES);
        if (!rctrlr->ctrlr.adminq) {
                SPDK_ERRLOG("failed to create admin qpair\n");
                nvme_rdma_ctrlr_destruct(&rctrlr->ctrlr);
                return NULL;
        }

        if (nvme_ctrlr_get_cap(&rctrlr->ctrlr, &cap)) {
                SPDK_ERRLOG("get_cap() failed\n");
                nvme_ctrlr_destruct(&rctrlr->ctrlr);
                return NULL;
        }

        if (nvme_ctrlr_get_vs(&rctrlr->ctrlr, &vs)) {
                SPDK_ERRLOG("get_vs() failed\n");
                nvme_ctrlr_destruct(&rctrlr->ctrlr);
                return NULL;
        }

        if (nvme_ctrlr_add_process(&rctrlr->ctrlr, 0) != 0) {
                SPDK_ERRLOG("nvme_ctrlr_add_process() failed\n");
                nvme_ctrlr_destruct(&rctrlr->ctrlr);
                return NULL;
        }

        nvme_ctrlr_init_cap(&rctrlr->ctrlr, &cap, &vs);

        SPDK_DEBUGLOG(SPDK_LOG_NVME, "successfully initialized the nvmf ctrlr\n");
        return &rctrlr->ctrlr;
}

int
nvme_rdma_ctrlr_destruct(struct spdk_nvme_ctrlr *ctrlr)
{
        struct nvme_rdma_ctrlr *rctrlr = nvme_rdma_ctrlr(ctrlr);

        if (ctrlr->adminq) {
                nvme_rdma_qpair_destroy(ctrlr->adminq);
        }

        nvme_ctrlr_destruct_finish(ctrlr);

        free(rctrlr);

        return 0;
}

int
nvme_rdma_ctrlr_set_reg_4(struct spdk_nvme_ctrlr *ctrlr, uint32_t offset, uint32_t value)
{
        return nvme_fabric_ctrlr_set_reg_4(ctrlr, offset, value);
}

int
nvme_rdma_ctrlr_set_reg_8(struct spdk_nvme_ctrlr *ctrlr, uint32_t offset, uint64_t value)
{
        return nvme_fabric_ctrlr_set_reg_8(ctrlr, offset, value);
}

int
nvme_rdma_ctrlr_get_reg_4(struct spdk_nvme_ctrlr *ctrlr, uint32_t offset, uint32_t *value)
{
        return nvme_fabric_ctrlr_get_reg_4(ctrlr, offset, value);
}

int
nvme_rdma_ctrlr_get_reg_8(struct spdk_nvme_ctrlr *ctrlr, uint32_t offset, uint64_t *value)
{
        return nvme_fabric_ctrlr_get_reg_8(ctrlr, offset, value);
}

int
nvme_rdma_qpair_submit_request(struct spdk_nvme_qpair *qpair,
                               struct nvme_request *req)
{
        struct nvme_rdma_qpair *rqpair;
        struct spdk_nvme_rdma_req *rdma_req;
        struct ibv_send_wr *wr, *bad_wr = NULL;
        int rc;

        rqpair = nvme_rdma_qpair(qpair);
        assert(rqpair != NULL);
        assert(req != NULL);

        rdma_req = nvme_rdma_req_get(rqpair);
        if (!rdma_req) {
                /*
                 * No rdma_req is available, so queue the request to be
                 *  processed later.
                 */
                STAILQ_INSERT_TAIL(&qpair->queued_req, req, stailq);
                return 0;
        }

        if (nvme_rdma_req_init(rqpair, req, rdma_req)) {
                SPDK_ERRLOG("nvme_rdma_req_init() failed\n");
                nvme_rdma_req_put(rqpair, rdma_req);
                return -1;
        }

        wr = &rdma_req->send_wr;

        nvme_rdma_trace_ibv_sge(wr->sg_list);

        rc = ibv_post_send(rqpair->cm_id->qp, wr, &bad_wr);
        if (rc) {
                SPDK_ERRLOG("Failure posting rdma send for NVMf completion: %d (%s)\n", rc, spdk_strerror(rc));
        }

        return rc;
}

int
nvme_rdma_ctrlr_delete_io_qpair(struct spdk_nvme_ctrlr *ctrlr, struct spdk_nvme_qpair *qpair)
{
        return nvme_rdma_qpair_destroy(qpair);
}

int
nvme_rdma_ctrlr_connect_qpair(struct spdk_nvme_ctrlr *ctrlr, struct spdk_nvme_qpair *qpair)
{
        return nvme_rdma_qpair_connect(nvme_rdma_qpair(qpair));
}

void
nvme_rdma_ctrlr_disconnect_qpair(struct spdk_nvme_ctrlr *ctrlr, struct spdk_nvme_qpair *qpair)
{
        nvme_rdma_qpair_disconnect(qpair);
}

int
nvme_rdma_qpair_reset(struct spdk_nvme_qpair *qpair)
{
        /* Currently, doing nothing here */
        return 0;
}

void
nvme_rdma_qpair_abort_reqs(struct spdk_nvme_qpair *qpair, uint32_t dnr)
{
        struct spdk_nvme_rdma_req *rdma_req, *tmp;
        struct nvme_request *req;
        struct spdk_nvme_cpl cpl;
        struct nvme_rdma_qpair *rqpair = nvme_rdma_qpair(qpair);

        cpl.status.sc = SPDK_NVME_SC_ABORTED_SQ_DELETION;
        cpl.status.sct = SPDK_NVME_SCT_GENERIC;
        cpl.status.dnr = dnr;

        TAILQ_FOREACH_SAFE(rdma_req, &rqpair->outstanding_reqs, link, tmp) {
                assert(rdma_req->req != NULL);
                req = rdma_req->req;

                nvme_rdma_req_complete(req, &cpl);
                nvme_rdma_req_put(rqpair, rdma_req);
        }
}

static void
nvme_rdma_qpair_check_timeout(struct spdk_nvme_qpair *qpair)
{
        uint64_t t02;
        struct spdk_nvme_rdma_req *rdma_req, *tmp;
        struct nvme_rdma_qpair *rqpair = nvme_rdma_qpair(qpair);
        struct spdk_nvme_ctrlr *ctrlr = qpair->ctrlr;
        struct spdk_nvme_ctrlr_process *active_proc;

        /* Don't check timeouts during controller initialization. */
        if (ctrlr->state != NVME_CTRLR_STATE_READY) {
                return;
        }

        if (nvme_qpair_is_admin_queue(qpair)) {
                active_proc = spdk_nvme_ctrlr_get_current_process(ctrlr);
        } else {
                active_proc = qpair->active_proc;
        }

        /* Only check timeouts if the current process has a timeout callback. */
        if (active_proc == NULL || active_proc->timeout_cb_fn == NULL) {
                return;
        }

        t02 = spdk_get_ticks();
        TAILQ_FOREACH_SAFE(rdma_req, &rqpair->outstanding_reqs, link, tmp) {
                assert(rdma_req->req != NULL);

                if (nvme_request_check_timeout(rdma_req->req, rdma_req->id, active_proc, t02)) {
                        /*
                         * The requests are in order, so as soon as one has not timed out,
                         * stop iterating.
                         */
                        break;
                }
        }
}

#define MAX_COMPLETIONS_PER_POLL 128

int
nvme_rdma_qpair_process_completions(struct spdk_nvme_qpair *qpair,
                                    uint32_t max_completions)
{
        struct nvme_rdma_qpair          *rqpair = nvme_rdma_qpair(qpair);
        struct ibv_wc                   wc[MAX_COMPLETIONS_PER_POLL];
        int                             i, rc, batch_size;
        uint32_t                        reaped;
        struct ibv_cq                   *cq;
        struct spdk_nvme_rdma_req       *rdma_req;

        if (max_completions == 0) {
                max_completions = rqpair->num_entries;
        } else {
                max_completions = spdk_min(max_completions, rqpair->num_entries);
        }

        cq = rqpair->cq;

        reaped = 0;
        do {
                batch_size = spdk_min((max_completions - reaped),
                                      MAX_COMPLETIONS_PER_POLL);
                rc = ibv_poll_cq(cq, batch_size, wc);
                if (rc < 0) {
                        SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
                                    errno, spdk_strerror(errno));
                        return -1;
                } else if (rc == 0) {
                        /* Ran out of completions */
                        break;
                }

                for (i = 0; i < rc; i++) {
                        if (wc[i].status) {
                                SPDK_ERRLOG("CQ error on Queue Pair %p, Response Index %lu (%d): %s\n",
                                            qpair, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
                                return -1;
                        }

                        switch (wc[i].opcode) {
                        case IBV_WC_RECV:
                                SPDK_DEBUGLOG(SPDK_LOG_NVME, "CQ recv completion\n");

                                reaped++;

                                if (wc[i].byte_len < sizeof(struct spdk_nvme_cpl)) {
                                        SPDK_ERRLOG("recv length %u less than expected response size\n", wc[i].byte_len);
                                        return -1;
                                }

                                if (nvme_rdma_recv(rqpair, wc[i].wr_id)) {
                                        SPDK_ERRLOG("nvme_rdma_recv processing failure\n");
                                        return -1;
                                }
                                break;

                        case IBV_WC_SEND:
                                rdma_req = (struct spdk_nvme_rdma_req *)wc[i].wr_id;

                                if (rdma_req->request_ready_to_put) {
                                        nvme_rdma_req_put(rqpair, rdma_req);
                                } else {
                                        rdma_req->request_ready_to_put = true;
                                }
                                break;

                        default:
                                SPDK_ERRLOG("Received an unexpected opcode on the CQ: %d\n", wc[i].opcode);
                                return -1;
                        }
                }
        } while (reaped < max_completions);

        if (spdk_unlikely(rqpair->qpair.ctrlr->timeout_enabled)) {
                nvme_rdma_qpair_check_timeout(qpair);
        }

        return reaped;
}

uint32_t
nvme_rdma_ctrlr_get_max_xfer_size(struct spdk_nvme_ctrlr *ctrlr)
{
        /* Todo, which should get from the NVMF target */
        return NVME_RDMA_RW_BUFFER_SIZE;
}

uint16_t
nvme_rdma_ctrlr_get_max_sges(struct spdk_nvme_ctrlr *ctrlr)
{
        return spdk_min(ctrlr->cdata.nvmf_specific.msdbd, NVME_RDMA_MAX_SGL_DESCRIPTORS);
}

volatile struct spdk_nvme_registers *
nvme_rdma_ctrlr_get_registers(struct spdk_nvme_ctrlr *ctrlr)
{
        return NULL;
}

void *
nvme_rdma_ctrlr_alloc_cmb_io_buffer(struct spdk_nvme_ctrlr *ctrlr, size_t size)
{
        return NULL;
}

int
nvme_rdma_ctrlr_free_cmb_io_buffer(struct spdk_nvme_ctrlr *ctrlr, void *buf, size_t size)
{
        return 0;
}

void
nvme_rdma_admin_qpair_abort_aers(struct spdk_nvme_qpair *qpair)
{
        struct spdk_nvme_rdma_req *rdma_req, *tmp;
        struct nvme_request *req;
        struct spdk_nvme_cpl cpl;
        struct nvme_rdma_qpair *rqpair = nvme_rdma_qpair(qpair);

        cpl.status.sc = SPDK_NVME_SC_ABORTED_SQ_DELETION;
        cpl.status.sct = SPDK_NVME_SCT_GENERIC;

        TAILQ_FOREACH_SAFE(rdma_req, &rqpair->outstanding_reqs, link, tmp) {
                if (rdma_req->req->cmd.opc != SPDK_NVME_OPC_ASYNC_EVENT_REQUEST) {
                        continue;
                }
                assert(rdma_req->req != NULL);
                req = rdma_req->req;

                nvme_rdma_req_complete(req, &cpl);
                nvme_rdma_req_put(rqpair, rdma_req);
        }
}

void
spdk_nvme_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
{
        g_nvme_hooks = *hooks;
}