qemu/hw/rdma/rdma_backend.c
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   1/*
   2 * QEMU paravirtual RDMA - Generic RDMA backend
   3 *
   4 * Copyright (C) 2018 Oracle
   5 * Copyright (C) 2018 Red Hat Inc
   6 *
   7 * Authors:
   8 *     Yuval Shaia <yuval.shaia@oracle.com>
   9 *     Marcel Apfelbaum <marcel@redhat.com>
  10 *
  11 * This work is licensed under the terms of the GNU GPL, version 2 or later.
  12 * See the COPYING file in the top-level directory.
  13 *
  14 */
  15
  16#include "qemu/osdep.h"
  17#include "qemu/error-report.h"
  18#include "qapi/error.h"
  19
  20#include <infiniband/verbs.h>
  21
  22#include "trace.h"
  23#include "rdma_utils.h"
  24#include "rdma_rm.h"
  25#include "rdma_backend.h"
  26
  27/* Vendor Errors */
  28#define VENDOR_ERR_FAIL_BACKEND     0x201
  29#define VENDOR_ERR_TOO_MANY_SGES    0x202
  30#define VENDOR_ERR_NOMEM            0x203
  31#define VENDOR_ERR_QP0              0x204
  32#define VENDOR_ERR_NO_SGE           0x205
  33#define VENDOR_ERR_MAD_SEND         0x206
  34#define VENDOR_ERR_INVLKEY          0x207
  35#define VENDOR_ERR_MR_SMALL         0x208
  36
  37#define THR_NAME_LEN 16
  38
  39typedef struct BackendCtx {
  40    uint64_t req_id;
  41    void *up_ctx;
  42    bool is_tx_req;
  43} BackendCtx;
  44
  45static void (*comp_handler)(int status, unsigned int vendor_err, void *ctx);
  46
  47static void dummy_comp_handler(int status, unsigned int vendor_err, void *ctx)
  48{
  49    pr_err("No completion handler is registered\n");
  50}
  51
  52static void poll_cq(RdmaDeviceResources *rdma_dev_res, struct ibv_cq *ibcq)
  53{
  54    int i, ne;
  55    BackendCtx *bctx;
  56    struct ibv_wc wc[2];
  57
  58    pr_dbg("Entering poll_cq loop on cq %p\n", ibcq);
  59    do {
  60        ne = ibv_poll_cq(ibcq, ARRAY_SIZE(wc), wc);
  61
  62        pr_dbg("Got %d completion(s) from cq %p\n", ne, ibcq);
  63
  64        for (i = 0; i < ne; i++) {
  65            pr_dbg("wr_id=0x%" PRIx64 "\n", wc[i].wr_id);
  66            pr_dbg("status=%d\n", wc[i].status);
  67
  68            bctx = rdma_rm_get_cqe_ctx(rdma_dev_res, wc[i].wr_id);
  69            if (unlikely(!bctx)) {
  70                pr_dbg("Error: Failed to find ctx for req %" PRId64 "\n",
  71                       wc[i].wr_id);
  72                continue;
  73            }
  74            pr_dbg("Processing %s CQE\n", bctx->is_tx_req ? "send" : "recv");
  75
  76            comp_handler(wc[i].status, wc[i].vendor_err, bctx->up_ctx);
  77
  78            rdma_rm_dealloc_cqe_ctx(rdma_dev_res, wc[i].wr_id);
  79            g_free(bctx);
  80        }
  81    } while (ne > 0);
  82
  83    if (ne < 0) {
  84        pr_dbg("Got error %d from ibv_poll_cq\n", ne);
  85    }
  86}
  87
  88static void *comp_handler_thread(void *arg)
  89{
  90    RdmaBackendDev *backend_dev = (RdmaBackendDev *)arg;
  91    int rc;
  92    struct ibv_cq *ev_cq;
  93    void *ev_ctx;
  94
  95    pr_dbg("Starting\n");
  96
  97    while (backend_dev->comp_thread.run) {
  98        pr_dbg("Waiting for completion on channel %p\n", backend_dev->channel);
  99        rc = ibv_get_cq_event(backend_dev->channel, &ev_cq, &ev_ctx);
 100        pr_dbg("ibv_get_cq_event=%d\n", rc);
 101        if (unlikely(rc)) {
 102            pr_dbg("---> ibv_get_cq_event (%d)\n", rc);
 103            continue;
 104        }
 105
 106        rc = ibv_req_notify_cq(ev_cq, 0);
 107        if (unlikely(rc)) {
 108            pr_dbg("Error %d from ibv_req_notify_cq\n", rc);
 109        }
 110
 111        poll_cq(backend_dev->rdma_dev_res, ev_cq);
 112
 113        ibv_ack_cq_events(ev_cq, 1);
 114    }
 115
 116    pr_dbg("Going down\n");
 117
 118    /* TODO: Post cqe for all remaining buffs that were posted */
 119
 120    return NULL;
 121}
 122
 123void rdma_backend_register_comp_handler(void (*handler)(int status,
 124                                        unsigned int vendor_err, void *ctx))
 125{
 126    comp_handler = handler;
 127}
 128
 129void rdma_backend_unregister_comp_handler(void)
 130{
 131    rdma_backend_register_comp_handler(dummy_comp_handler);
 132}
 133
 134int rdma_backend_query_port(RdmaBackendDev *backend_dev,
 135                            struct ibv_port_attr *port_attr)
 136{
 137    int rc;
 138
 139    rc = ibv_query_port(backend_dev->context, backend_dev->port_num, port_attr);
 140    if (rc) {
 141        pr_dbg("Error %d from ibv_query_port\n", rc);
 142        return -EIO;
 143    }
 144
 145    return 0;
 146}
 147
 148void rdma_backend_poll_cq(RdmaDeviceResources *rdma_dev_res, RdmaBackendCQ *cq)
 149{
 150    poll_cq(rdma_dev_res, cq->ibcq);
 151}
 152
 153static GHashTable *ah_hash;
 154
 155static struct ibv_ah *create_ah(RdmaBackendDev *backend_dev, struct ibv_pd *pd,
 156                                uint8_t sgid_idx, union ibv_gid *dgid)
 157{
 158    GBytes *ah_key = g_bytes_new(dgid, sizeof(*dgid));
 159    struct ibv_ah *ah = g_hash_table_lookup(ah_hash, ah_key);
 160
 161    if (ah) {
 162        trace_create_ah_cache_hit(be64_to_cpu(dgid->global.subnet_prefix),
 163                                  be64_to_cpu(dgid->global.interface_id));
 164        g_bytes_unref(ah_key);
 165    } else {
 166        struct ibv_ah_attr ah_attr = {
 167            .is_global     = 1,
 168            .port_num      = backend_dev->port_num,
 169            .grh.hop_limit = 1,
 170        };
 171
 172        ah_attr.grh.dgid = *dgid;
 173        ah_attr.grh.sgid_index = sgid_idx;
 174
 175        ah = ibv_create_ah(pd, &ah_attr);
 176        if (ah) {
 177            g_hash_table_insert(ah_hash, ah_key, ah);
 178        } else {
 179            g_bytes_unref(ah_key);
 180            pr_dbg("Fail to create AH for gid <0x%" PRIx64 ", 0x%" PRIx64 ">\n",
 181                    be64_to_cpu(dgid->global.subnet_prefix),
 182                    be64_to_cpu(dgid->global.interface_id));
 183        }
 184
 185        trace_create_ah_cache_miss(be64_to_cpu(dgid->global.subnet_prefix),
 186                                   be64_to_cpu(dgid->global.interface_id));
 187    }
 188
 189    return ah;
 190}
 191
 192static void destroy_ah_hash_key(gpointer data)
 193{
 194    g_bytes_unref(data);
 195}
 196
 197static void destroy_ah_hast_data(gpointer data)
 198{
 199    struct ibv_ah *ah = data;
 200
 201    ibv_destroy_ah(ah);
 202}
 203
 204static void ah_cache_init(void)
 205{
 206    ah_hash = g_hash_table_new_full(g_bytes_hash, g_bytes_equal,
 207                                    destroy_ah_hash_key, destroy_ah_hast_data);
 208}
 209
 210static int build_host_sge_array(RdmaDeviceResources *rdma_dev_res,
 211                                struct ibv_sge *dsge, struct ibv_sge *ssge,
 212                                uint8_t num_sge)
 213{
 214    RdmaRmMR *mr;
 215    int ssge_idx;
 216
 217    pr_dbg("num_sge=%d\n", num_sge);
 218
 219    for (ssge_idx = 0; ssge_idx < num_sge; ssge_idx++) {
 220        mr = rdma_rm_get_mr(rdma_dev_res, ssge[ssge_idx].lkey);
 221        if (unlikely(!mr)) {
 222            pr_dbg("Invalid lkey 0x%x\n", ssge[ssge_idx].lkey);
 223            return VENDOR_ERR_INVLKEY | ssge[ssge_idx].lkey;
 224        }
 225
 226        dsge->addr = (uintptr_t)mr->user_mr.host_virt + ssge[ssge_idx].addr -
 227                     mr->user_mr.guest_start;
 228        dsge->length = ssge[ssge_idx].length;
 229        dsge->lkey = rdma_backend_mr_lkey(&mr->backend_mr);
 230
 231        pr_dbg("ssge->addr=0x%" PRIx64 "\n", ssge[ssge_idx].addr);
 232        pr_dbg("dsge->addr=0x%" PRIx64 "\n", dsge->addr);
 233        pr_dbg("dsge->length=%d\n", dsge->length);
 234        pr_dbg("dsge->lkey=0x%x\n", dsge->lkey);
 235
 236        dsge++;
 237    }
 238
 239    return 0;
 240}
 241
 242void rdma_backend_post_send(RdmaBackendDev *backend_dev,
 243                            RdmaBackendQP *qp, uint8_t qp_type,
 244                            struct ibv_sge *sge, uint32_t num_sge,
 245                            union ibv_gid *dgid, uint32_t dqpn,
 246                            uint32_t dqkey, void *ctx)
 247{
 248    BackendCtx *bctx;
 249    struct ibv_sge new_sge[MAX_SGE];
 250    uint32_t bctx_id;
 251    int rc;
 252    struct ibv_send_wr wr = {0}, *bad_wr;
 253
 254    if (!qp->ibqp) { /* This field does not get initialized for QP0 and QP1 */
 255        if (qp_type == IBV_QPT_SMI) {
 256            pr_dbg("QP0 unsupported\n");
 257            comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_QP0, ctx);
 258        } else if (qp_type == IBV_QPT_GSI) {
 259            pr_dbg("QP1\n");
 260            comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_MAD_SEND, ctx);
 261        }
 262        pr_dbg("qp->ibqp is NULL for qp_type %d!!!\n", qp_type);
 263        return;
 264    }
 265
 266    pr_dbg("num_sge=%d\n", num_sge);
 267    if (!num_sge) {
 268        pr_dbg("num_sge=0\n");
 269        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_NO_SGE, ctx);
 270        return;
 271    }
 272
 273    bctx = g_malloc0(sizeof(*bctx));
 274    bctx->up_ctx = ctx;
 275    bctx->is_tx_req = 1;
 276
 277    rc = rdma_rm_alloc_cqe_ctx(backend_dev->rdma_dev_res, &bctx_id, bctx);
 278    if (unlikely(rc)) {
 279        pr_dbg("Failed to allocate cqe_ctx\n");
 280        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_NOMEM, ctx);
 281        goto out_free_bctx;
 282    }
 283
 284    rc = build_host_sge_array(backend_dev->rdma_dev_res, new_sge, sge, num_sge);
 285    if (rc) {
 286        pr_dbg("Error: Failed to build host SGE array\n");
 287        comp_handler(IBV_WC_GENERAL_ERR, rc, ctx);
 288        goto out_dealloc_cqe_ctx;
 289    }
 290
 291    if (qp_type == IBV_QPT_UD) {
 292        wr.wr.ud.ah = create_ah(backend_dev, qp->ibpd,
 293                                backend_dev->backend_gid_idx, dgid);
 294        wr.wr.ud.remote_qpn = dqpn;
 295        wr.wr.ud.remote_qkey = dqkey;
 296    }
 297
 298    wr.num_sge = num_sge;
 299    wr.opcode = IBV_WR_SEND;
 300    wr.send_flags = IBV_SEND_SIGNALED;
 301    wr.sg_list = new_sge;
 302    wr.wr_id = bctx_id;
 303
 304    rc = ibv_post_send(qp->ibqp, &wr, &bad_wr);
 305    pr_dbg("ibv_post_send=%d\n", rc);
 306    if (rc) {
 307        pr_dbg("Fail (%d, %d) to post send WQE to qpn %d\n", rc, errno,
 308                qp->ibqp->qp_num);
 309        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_FAIL_BACKEND, ctx);
 310        goto out_dealloc_cqe_ctx;
 311    }
 312
 313    return;
 314
 315out_dealloc_cqe_ctx:
 316    rdma_rm_dealloc_cqe_ctx(backend_dev->rdma_dev_res, bctx_id);
 317
 318out_free_bctx:
 319    g_free(bctx);
 320}
 321
 322void rdma_backend_post_recv(RdmaBackendDev *backend_dev,
 323                            RdmaDeviceResources *rdma_dev_res,
 324                            RdmaBackendQP *qp, uint8_t qp_type,
 325                            struct ibv_sge *sge, uint32_t num_sge, void *ctx)
 326{
 327    BackendCtx *bctx;
 328    struct ibv_sge new_sge[MAX_SGE];
 329    uint32_t bctx_id;
 330    int rc;
 331    struct ibv_recv_wr wr = {0}, *bad_wr;
 332
 333    if (!qp->ibqp) { /* This field does not get initialized for QP0 and QP1 */
 334        if (qp_type == IBV_QPT_SMI) {
 335            pr_dbg("QP0 unsupported\n");
 336            comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_QP0, ctx);
 337        }
 338        if (qp_type == IBV_QPT_GSI) {
 339            pr_dbg("QP1\n");
 340            comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_MAD_SEND, ctx);
 341        }
 342        return;
 343    }
 344
 345    pr_dbg("num_sge=%d\n", num_sge);
 346    if (!num_sge) {
 347        pr_dbg("num_sge=0\n");
 348        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_NO_SGE, ctx);
 349        return;
 350    }
 351
 352    bctx = g_malloc0(sizeof(*bctx));
 353    bctx->up_ctx = ctx;
 354    bctx->is_tx_req = 0;
 355
 356    rc = rdma_rm_alloc_cqe_ctx(rdma_dev_res, &bctx_id, bctx);
 357    if (unlikely(rc)) {
 358        pr_dbg("Failed to allocate cqe_ctx\n");
 359        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_NOMEM, ctx);
 360        goto out_free_bctx;
 361    }
 362
 363    rc = build_host_sge_array(rdma_dev_res, new_sge, sge, num_sge);
 364    if (rc) {
 365        pr_dbg("Error: Failed to build host SGE array\n");
 366        comp_handler(IBV_WC_GENERAL_ERR, rc, ctx);
 367        goto out_dealloc_cqe_ctx;
 368    }
 369
 370    wr.num_sge = num_sge;
 371    wr.sg_list = new_sge;
 372    wr.wr_id = bctx_id;
 373    rc = ibv_post_recv(qp->ibqp, &wr, &bad_wr);
 374    pr_dbg("ibv_post_recv=%d\n", rc);
 375    if (rc) {
 376        pr_dbg("Fail (%d, %d) to post recv WQE to qpn %d\n", rc, errno,
 377                qp->ibqp->qp_num);
 378        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_FAIL_BACKEND, ctx);
 379        goto out_dealloc_cqe_ctx;
 380    }
 381
 382    return;
 383
 384out_dealloc_cqe_ctx:
 385    rdma_rm_dealloc_cqe_ctx(rdma_dev_res, bctx_id);
 386
 387out_free_bctx:
 388    g_free(bctx);
 389}
 390
 391int rdma_backend_create_pd(RdmaBackendDev *backend_dev, RdmaBackendPD *pd)
 392{
 393    pd->ibpd = ibv_alloc_pd(backend_dev->context);
 394
 395    return pd->ibpd ? 0 : -EIO;
 396}
 397
 398void rdma_backend_destroy_pd(RdmaBackendPD *pd)
 399{
 400    if (pd->ibpd) {
 401        ibv_dealloc_pd(pd->ibpd);
 402    }
 403}
 404
 405int rdma_backend_create_mr(RdmaBackendMR *mr, RdmaBackendPD *pd, void *addr,
 406                           size_t length, int access)
 407{
 408    pr_dbg("addr=0x%p\n", addr);
 409    pr_dbg("len=%zu\n", length);
 410    mr->ibmr = ibv_reg_mr(pd->ibpd, addr, length, access);
 411    if (mr->ibmr) {
 412        pr_dbg("lkey=0x%x\n", mr->ibmr->lkey);
 413        pr_dbg("rkey=0x%x\n", mr->ibmr->rkey);
 414        mr->ibpd = pd->ibpd;
 415    }
 416
 417    return mr->ibmr ? 0 : -EIO;
 418}
 419
 420void rdma_backend_destroy_mr(RdmaBackendMR *mr)
 421{
 422    if (mr->ibmr) {
 423        ibv_dereg_mr(mr->ibmr);
 424    }
 425}
 426
 427int rdma_backend_create_cq(RdmaBackendDev *backend_dev, RdmaBackendCQ *cq,
 428                           int cqe)
 429{
 430    int rc;
 431
 432    pr_dbg("cqe=%d\n", cqe);
 433
 434    pr_dbg("dev->channel=%p\n", backend_dev->channel);
 435    cq->ibcq = ibv_create_cq(backend_dev->context, cqe + 1, NULL,
 436                             backend_dev->channel, 0);
 437
 438    if (cq->ibcq) {
 439        rc = ibv_req_notify_cq(cq->ibcq, 0);
 440        if (rc) {
 441            pr_dbg("Error %d from ibv_req_notify_cq\n", rc);
 442        }
 443        cq->backend_dev = backend_dev;
 444    }
 445
 446    return cq->ibcq ? 0 : -EIO;
 447}
 448
 449void rdma_backend_destroy_cq(RdmaBackendCQ *cq)
 450{
 451    if (cq->ibcq) {
 452        ibv_destroy_cq(cq->ibcq);
 453    }
 454}
 455
 456int rdma_backend_create_qp(RdmaBackendQP *qp, uint8_t qp_type,
 457                           RdmaBackendPD *pd, RdmaBackendCQ *scq,
 458                           RdmaBackendCQ *rcq, uint32_t max_send_wr,
 459                           uint32_t max_recv_wr, uint32_t max_send_sge,
 460                           uint32_t max_recv_sge)
 461{
 462    struct ibv_qp_init_attr attr = {0};
 463
 464    qp->ibqp = 0;
 465    pr_dbg("qp_type=%d\n", qp_type);
 466
 467    switch (qp_type) {
 468    case IBV_QPT_GSI:
 469        pr_dbg("QP1 unsupported\n");
 470        return 0;
 471
 472    case IBV_QPT_RC:
 473        /* fall through */
 474    case IBV_QPT_UD:
 475        /* do nothing */
 476        break;
 477
 478    default:
 479        pr_dbg("Unsupported QP type %d\n", qp_type);
 480        return -EIO;
 481    }
 482
 483    attr.qp_type = qp_type;
 484    attr.send_cq = scq->ibcq;
 485    attr.recv_cq = rcq->ibcq;
 486    attr.cap.max_send_wr = max_send_wr;
 487    attr.cap.max_recv_wr = max_recv_wr;
 488    attr.cap.max_send_sge = max_send_sge;
 489    attr.cap.max_recv_sge = max_recv_sge;
 490
 491    pr_dbg("max_send_wr=%d\n", max_send_wr);
 492    pr_dbg("max_recv_wr=%d\n", max_recv_wr);
 493    pr_dbg("max_send_sge=%d\n", max_send_sge);
 494    pr_dbg("max_recv_sge=%d\n", max_recv_sge);
 495
 496    qp->ibqp = ibv_create_qp(pd->ibpd, &attr);
 497    if (likely(!qp->ibqp)) {
 498        pr_dbg("Error from ibv_create_qp\n");
 499        return -EIO;
 500    }
 501
 502    qp->ibpd = pd->ibpd;
 503
 504    /* TODO: Query QP to get max_inline_data and save it to be used in send */
 505
 506    pr_dbg("qpn=0x%x\n", qp->ibqp->qp_num);
 507
 508    return 0;
 509}
 510
 511int rdma_backend_qp_state_init(RdmaBackendDev *backend_dev, RdmaBackendQP *qp,
 512                               uint8_t qp_type, uint32_t qkey)
 513{
 514    struct ibv_qp_attr attr = {0};
 515    int rc, attr_mask;
 516
 517    pr_dbg("qpn=0x%x\n", qp->ibqp->qp_num);
 518    pr_dbg("sport_num=%d\n", backend_dev->port_num);
 519
 520    attr_mask = IBV_QP_STATE | IBV_QP_PKEY_INDEX | IBV_QP_PORT;
 521    attr.qp_state        = IBV_QPS_INIT;
 522    attr.pkey_index      = 0;
 523    attr.port_num        = backend_dev->port_num;
 524
 525    switch (qp_type) {
 526    case IBV_QPT_RC:
 527        attr_mask |= IBV_QP_ACCESS_FLAGS;
 528        break;
 529
 530    case IBV_QPT_UD:
 531        attr.qkey = qkey;
 532        attr_mask |= IBV_QP_QKEY;
 533        break;
 534
 535    default:
 536        pr_dbg("Unsupported QP type %d\n", qp_type);
 537        return -EIO;
 538    }
 539
 540    rc = ibv_modify_qp(qp->ibqp, &attr, attr_mask);
 541    if (rc) {
 542        pr_dbg("Error %d from ibv_modify_qp\n", rc);
 543        return -EIO;
 544    }
 545
 546    return 0;
 547}
 548
 549int rdma_backend_qp_state_rtr(RdmaBackendDev *backend_dev, RdmaBackendQP *qp,
 550                              uint8_t qp_type, union ibv_gid *dgid,
 551                              uint32_t dqpn, uint32_t rq_psn, uint32_t qkey,
 552                              bool use_qkey)
 553{
 554    struct ibv_qp_attr attr = {0};
 555    union ibv_gid ibv_gid = {
 556        .global.interface_id = dgid->global.interface_id,
 557        .global.subnet_prefix = dgid->global.subnet_prefix
 558    };
 559    int rc, attr_mask;
 560
 561    attr.qp_state = IBV_QPS_RTR;
 562    attr_mask = IBV_QP_STATE;
 563
 564    switch (qp_type) {
 565    case IBV_QPT_RC:
 566        pr_dbg("dgid=0x%" PRIx64 ",%" PRIx64 "\n",
 567               be64_to_cpu(ibv_gid.global.subnet_prefix),
 568               be64_to_cpu(ibv_gid.global.interface_id));
 569        pr_dbg("dqpn=0x%x\n", dqpn);
 570        pr_dbg("sgid_idx=%d\n", backend_dev->backend_gid_idx);
 571        pr_dbg("sport_num=%d\n", backend_dev->port_num);
 572        pr_dbg("rq_psn=0x%x\n", rq_psn);
 573
 574        attr.path_mtu               = IBV_MTU_1024;
 575        attr.dest_qp_num            = dqpn;
 576        attr.max_dest_rd_atomic     = 1;
 577        attr.min_rnr_timer          = 12;
 578        attr.ah_attr.port_num       = backend_dev->port_num;
 579        attr.ah_attr.is_global      = 1;
 580        attr.ah_attr.grh.hop_limit  = 1;
 581        attr.ah_attr.grh.dgid       = ibv_gid;
 582        attr.ah_attr.grh.sgid_index = backend_dev->backend_gid_idx;
 583        attr.rq_psn                 = rq_psn;
 584
 585        attr_mask |= IBV_QP_AV | IBV_QP_PATH_MTU | IBV_QP_DEST_QPN |
 586                     IBV_QP_RQ_PSN | IBV_QP_MAX_DEST_RD_ATOMIC |
 587                     IBV_QP_MIN_RNR_TIMER;
 588        break;
 589
 590    case IBV_QPT_UD:
 591        if (use_qkey) {
 592            pr_dbg("qkey=0x%x\n", qkey);
 593            attr.qkey = qkey;
 594            attr_mask |= IBV_QP_QKEY;
 595        }
 596        break;
 597    }
 598
 599    rc = ibv_modify_qp(qp->ibqp, &attr, attr_mask);
 600    if (rc) {
 601        pr_dbg("Error %d from ibv_modify_qp\n", rc);
 602        return -EIO;
 603    }
 604
 605    return 0;
 606}
 607
 608int rdma_backend_qp_state_rts(RdmaBackendQP *qp, uint8_t qp_type,
 609                              uint32_t sq_psn, uint32_t qkey, bool use_qkey)
 610{
 611    struct ibv_qp_attr attr = {0};
 612    int rc, attr_mask;
 613
 614    pr_dbg("qpn=0x%x\n", qp->ibqp->qp_num);
 615    pr_dbg("sq_psn=0x%x\n", sq_psn);
 616
 617    attr.qp_state = IBV_QPS_RTS;
 618    attr.sq_psn = sq_psn;
 619    attr_mask = IBV_QP_STATE | IBV_QP_SQ_PSN;
 620
 621    switch (qp_type) {
 622    case IBV_QPT_RC:
 623        attr.timeout       = 14;
 624        attr.retry_cnt     = 7;
 625        attr.rnr_retry     = 7;
 626        attr.max_rd_atomic = 1;
 627
 628        attr_mask |= IBV_QP_TIMEOUT | IBV_QP_RETRY_CNT | IBV_QP_RNR_RETRY |
 629                     IBV_QP_MAX_QP_RD_ATOMIC;
 630        break;
 631
 632    case IBV_QPT_UD:
 633        if (use_qkey) {
 634            pr_dbg("qkey=0x%x\n", qkey);
 635            attr.qkey = qkey;
 636            attr_mask |= IBV_QP_QKEY;
 637        }
 638        break;
 639    }
 640
 641    rc = ibv_modify_qp(qp->ibqp, &attr, attr_mask);
 642    if (rc) {
 643        pr_dbg("Error %d from ibv_modify_qp\n", rc);
 644        return -EIO;
 645    }
 646
 647    return 0;
 648}
 649
 650int rdma_backend_query_qp(RdmaBackendQP *qp, struct ibv_qp_attr *attr,
 651                          int attr_mask, struct ibv_qp_init_attr *init_attr)
 652{
 653    if (!qp->ibqp) {
 654        pr_dbg("QP1\n");
 655        attr->qp_state = IBV_QPS_RTS;
 656        return 0;
 657    }
 658
 659    return ibv_query_qp(qp->ibqp, attr, attr_mask, init_attr);
 660}
 661
 662void rdma_backend_destroy_qp(RdmaBackendQP *qp)
 663{
 664    if (qp->ibqp) {
 665        ibv_destroy_qp(qp->ibqp);
 666    }
 667}
 668
 669#define CHK_ATTR(req, dev, member, fmt) ({ \
 670    pr_dbg("%s="fmt","fmt"\n", #member, dev.member, req->member); \
 671    if (req->member > dev.member) { \
 672        warn_report("%s = "fmt" is higher than host device capability "fmt, \
 673                    #member, req->member, dev.member); \
 674        req->member = dev.member; \
 675    } \
 676    pr_dbg("%s="fmt"\n", #member, req->member); })
 677
 678static int init_device_caps(RdmaBackendDev *backend_dev,
 679                            struct ibv_device_attr *dev_attr)
 680{
 681    if (ibv_query_device(backend_dev->context, &backend_dev->dev_attr)) {
 682        return -EIO;
 683    }
 684
 685    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_mr_size, "%" PRId64);
 686    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_qp, "%d");
 687    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_sge, "%d");
 688    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_qp_wr, "%d");
 689    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_cq, "%d");
 690    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_cqe, "%d");
 691    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_mr, "%d");
 692    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_pd, "%d");
 693    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_qp_rd_atom, "%d");
 694    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_qp_init_rd_atom, "%d");
 695    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_ah, "%d");
 696
 697    return 0;
 698}
 699
 700int rdma_backend_init(RdmaBackendDev *backend_dev,
 701                      RdmaDeviceResources *rdma_dev_res,
 702                      const char *backend_device_name, uint8_t port_num,
 703                      uint8_t backend_gid_idx, struct ibv_device_attr *dev_attr,
 704                      Error **errp)
 705{
 706    int i;
 707    int ret = 0;
 708    int num_ibv_devices;
 709    char thread_name[THR_NAME_LEN] = {0};
 710    struct ibv_device **dev_list;
 711    struct ibv_port_attr port_attr;
 712
 713    backend_dev->backend_gid_idx = backend_gid_idx;
 714    backend_dev->port_num = port_num;
 715    backend_dev->rdma_dev_res = rdma_dev_res;
 716
 717    rdma_backend_register_comp_handler(dummy_comp_handler);
 718
 719    dev_list = ibv_get_device_list(&num_ibv_devices);
 720    if (!dev_list) {
 721        error_setg(errp, "Failed to get IB devices list");
 722        return -EIO;
 723    }
 724
 725    if (num_ibv_devices == 0) {
 726        error_setg(errp, "No IB devices were found");
 727        ret = -ENXIO;
 728        goto out_free_dev_list;
 729    }
 730
 731    if (backend_device_name) {
 732        for (i = 0; dev_list[i]; ++i) {
 733            if (!strcmp(ibv_get_device_name(dev_list[i]),
 734                        backend_device_name)) {
 735                break;
 736            }
 737        }
 738
 739        backend_dev->ib_dev = dev_list[i];
 740        if (!backend_dev->ib_dev) {
 741            error_setg(errp, "Failed to find IB device %s",
 742                       backend_device_name);
 743            ret = -EIO;
 744            goto out_free_dev_list;
 745        }
 746    } else {
 747        backend_dev->ib_dev = *dev_list;
 748    }
 749
 750    pr_dbg("Using backend device %s, port %d, gid_idx %d\n",
 751           ibv_get_device_name(backend_dev->ib_dev),
 752           backend_dev->port_num, backend_dev->backend_gid_idx);
 753
 754    backend_dev->context = ibv_open_device(backend_dev->ib_dev);
 755    if (!backend_dev->context) {
 756        error_setg(errp, "Failed to open IB device");
 757        ret = -EIO;
 758        goto out;
 759    }
 760
 761    backend_dev->channel = ibv_create_comp_channel(backend_dev->context);
 762    if (!backend_dev->channel) {
 763        error_setg(errp, "Failed to create IB communication channel");
 764        ret = -EIO;
 765        goto out_close_device;
 766    }
 767    pr_dbg("dev->backend_dev.channel=%p\n", backend_dev->channel);
 768
 769    ret = ibv_query_port(backend_dev->context, backend_dev->port_num,
 770                         &port_attr);
 771    if (ret) {
 772        error_setg(errp, "Error %d from ibv_query_port", ret);
 773        ret = -EIO;
 774        goto out_destroy_comm_channel;
 775    }
 776
 777    if (backend_dev->backend_gid_idx > port_attr.gid_tbl_len) {
 778        error_setg(errp, "Invalid backend_gid_idx, should be less than %d",
 779                   port_attr.gid_tbl_len);
 780        goto out_destroy_comm_channel;
 781    }
 782
 783    ret = init_device_caps(backend_dev, dev_attr);
 784    if (ret) {
 785        error_setg(errp, "Failed to initialize device capabilities");
 786        ret = -EIO;
 787        goto out_destroy_comm_channel;
 788    }
 789
 790    ret = ibv_query_gid(backend_dev->context, backend_dev->port_num,
 791                         backend_dev->backend_gid_idx, &backend_dev->gid);
 792    if (ret) {
 793        error_setg(errp, "Failed to query gid %d",
 794                   backend_dev->backend_gid_idx);
 795        ret = -EIO;
 796        goto out_destroy_comm_channel;
 797    }
 798    pr_dbg("subnet_prefix=0x%" PRIx64 "\n",
 799           be64_to_cpu(backend_dev->gid.global.subnet_prefix));
 800    pr_dbg("interface_id=0x%" PRIx64 "\n",
 801           be64_to_cpu(backend_dev->gid.global.interface_id));
 802
 803    snprintf(thread_name, sizeof(thread_name), "rdma_comp_%s",
 804             ibv_get_device_name(backend_dev->ib_dev));
 805    backend_dev->comp_thread.run = true;
 806    qemu_thread_create(&backend_dev->comp_thread.thread, thread_name,
 807                       comp_handler_thread, backend_dev, QEMU_THREAD_DETACHED);
 808
 809    ah_cache_init();
 810
 811    goto out_free_dev_list;
 812
 813out_destroy_comm_channel:
 814    ibv_destroy_comp_channel(backend_dev->channel);
 815
 816out_close_device:
 817    ibv_close_device(backend_dev->context);
 818
 819out_free_dev_list:
 820    ibv_free_device_list(dev_list);
 821
 822out:
 823    return ret;
 824}
 825
 826void rdma_backend_fini(RdmaBackendDev *backend_dev)
 827{
 828    g_hash_table_destroy(ah_hash);
 829    ibv_destroy_comp_channel(backend_dev->channel);
 830    ibv_close_device(backend_dev->context);
 831}
 832