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#define THR_POLL_TO  5000
  39
  40typedef struct BackendCtx {
  41    uint64_t req_id;
  42    void *up_ctx;
  43    bool is_tx_req;
  44} BackendCtx;
  45
  46static void (*comp_handler)(int status, unsigned int vendor_err, void *ctx);
  47
  48static void dummy_comp_handler(int status, unsigned int vendor_err, void *ctx)
  49{
  50    pr_err("No completion handler is registered\n");
  51}
  52
  53static void poll_cq(RdmaDeviceResources *rdma_dev_res, struct ibv_cq *ibcq)
  54{
  55    int i, ne;
  56    BackendCtx *bctx;
  57    struct ibv_wc wc[2];
  58
  59    pr_dbg("Entering poll_cq loop on cq %p\n", ibcq);
  60    do {
  61        ne = ibv_poll_cq(ibcq, ARRAY_SIZE(wc), wc);
  62
  63        pr_dbg("Got %d completion(s) from cq %p\n", ne, ibcq);
  64
  65        for (i = 0; i < ne; i++) {
  66            pr_dbg("wr_id=0x%" PRIx64 "\n", wc[i].wr_id);
  67            pr_dbg("status=%d\n", wc[i].status);
  68
  69            bctx = rdma_rm_get_cqe_ctx(rdma_dev_res, wc[i].wr_id);
  70            if (unlikely(!bctx)) {
  71                pr_dbg("Error: Failed to find ctx for req %" PRId64 "\n",
  72                       wc[i].wr_id);
  73                continue;
  74            }
  75            pr_dbg("Processing %s CQE\n", bctx->is_tx_req ? "send" : "recv");
  76
  77            comp_handler(wc[i].status, wc[i].vendor_err, bctx->up_ctx);
  78
  79            rdma_rm_dealloc_cqe_ctx(rdma_dev_res, wc[i].wr_id);
  80            g_free(bctx);
  81        }
  82    } while (ne > 0);
  83
  84    if (ne < 0) {
  85        pr_dbg("Got error %d from ibv_poll_cq\n", ne);
  86    }
  87}
  88
  89static void *comp_handler_thread(void *arg)
  90{
  91    RdmaBackendDev *backend_dev = (RdmaBackendDev *)arg;
  92    int rc;
  93    struct ibv_cq *ev_cq;
  94    void *ev_ctx;
  95    int flags;
  96    GPollFD pfds[1];
  97
  98    /* Change to non-blocking mode */
  99    flags = fcntl(backend_dev->channel->fd, F_GETFL);
 100    rc = fcntl(backend_dev->channel->fd, F_SETFL, flags | O_NONBLOCK);
 101    if (rc < 0) {
 102        pr_dbg("Fail to change to non-blocking mode\n");
 103        return NULL;
 104    }
 105
 106    pr_dbg("Starting\n");
 107
 108    pfds[0].fd = backend_dev->channel->fd;
 109    pfds[0].events = G_IO_IN | G_IO_HUP | G_IO_ERR;
 110
 111    backend_dev->comp_thread.is_running = true;
 112
 113    while (backend_dev->comp_thread.run) {
 114        do {
 115            rc = qemu_poll_ns(pfds, 1, THR_POLL_TO * (int64_t)SCALE_MS);
 116        } while (!rc && backend_dev->comp_thread.run);
 117
 118        if (backend_dev->comp_thread.run) {
 119            pr_dbg("Waiting for completion on channel %p\n", backend_dev->channel);
 120            rc = ibv_get_cq_event(backend_dev->channel, &ev_cq, &ev_ctx);
 121            pr_dbg("ibv_get_cq_event=%d\n", rc);
 122            if (unlikely(rc)) {
 123                pr_dbg("---> ibv_get_cq_event (%d)\n", rc);
 124                continue;
 125            }
 126
 127            rc = ibv_req_notify_cq(ev_cq, 0);
 128            if (unlikely(rc)) {
 129                pr_dbg("Error %d from ibv_req_notify_cq\n", rc);
 130            }
 131
 132            poll_cq(backend_dev->rdma_dev_res, ev_cq);
 133
 134            ibv_ack_cq_events(ev_cq, 1);
 135        }
 136    }
 137
 138    pr_dbg("Going down\n");
 139
 140    /* TODO: Post cqe for all remaining buffs that were posted */
 141
 142    backend_dev->comp_thread.is_running = false;
 143
 144    qemu_thread_exit(0);
 145
 146    return NULL;
 147}
 148
 149static void stop_backend_thread(RdmaBackendThread *thread)
 150{
 151    thread->run = false;
 152    while (thread->is_running) {
 153        pr_dbg("Waiting for thread to complete\n");
 154        sleep(THR_POLL_TO / SCALE_US / 2);
 155    }
 156}
 157
 158static void start_comp_thread(RdmaBackendDev *backend_dev)
 159{
 160    char thread_name[THR_NAME_LEN] = {0};
 161
 162    stop_backend_thread(&backend_dev->comp_thread);
 163
 164    snprintf(thread_name, sizeof(thread_name), "rdma_comp_%s",
 165             ibv_get_device_name(backend_dev->ib_dev));
 166    backend_dev->comp_thread.run = true;
 167    qemu_thread_create(&backend_dev->comp_thread.thread, thread_name,
 168                       comp_handler_thread, backend_dev, QEMU_THREAD_DETACHED);
 169}
 170
 171void rdma_backend_register_comp_handler(void (*handler)(int status,
 172                                        unsigned int vendor_err, void *ctx))
 173{
 174    comp_handler = handler;
 175}
 176
 177void rdma_backend_unregister_comp_handler(void)
 178{
 179    rdma_backend_register_comp_handler(dummy_comp_handler);
 180}
 181
 182int rdma_backend_query_port(RdmaBackendDev *backend_dev,
 183                            struct ibv_port_attr *port_attr)
 184{
 185    int rc;
 186
 187    rc = ibv_query_port(backend_dev->context, backend_dev->port_num, port_attr);
 188    if (rc) {
 189        pr_dbg("Error %d from ibv_query_port\n", rc);
 190        return -EIO;
 191    }
 192
 193    return 0;
 194}
 195
 196void rdma_backend_poll_cq(RdmaDeviceResources *rdma_dev_res, RdmaBackendCQ *cq)
 197{
 198    poll_cq(rdma_dev_res, cq->ibcq);
 199}
 200
 201static GHashTable *ah_hash;
 202
 203static struct ibv_ah *create_ah(RdmaBackendDev *backend_dev, struct ibv_pd *pd,
 204                                uint8_t sgid_idx, union ibv_gid *dgid)
 205{
 206    GBytes *ah_key = g_bytes_new(dgid, sizeof(*dgid));
 207    struct ibv_ah *ah = g_hash_table_lookup(ah_hash, ah_key);
 208
 209    if (ah) {
 210        trace_create_ah_cache_hit(be64_to_cpu(dgid->global.subnet_prefix),
 211                                  be64_to_cpu(dgid->global.interface_id));
 212        g_bytes_unref(ah_key);
 213    } else {
 214        struct ibv_ah_attr ah_attr = {
 215            .is_global     = 1,
 216            .port_num      = backend_dev->port_num,
 217            .grh.hop_limit = 1,
 218        };
 219
 220        ah_attr.grh.dgid = *dgid;
 221        ah_attr.grh.sgid_index = sgid_idx;
 222
 223        ah = ibv_create_ah(pd, &ah_attr);
 224        if (ah) {
 225            g_hash_table_insert(ah_hash, ah_key, ah);
 226        } else {
 227            g_bytes_unref(ah_key);
 228            pr_dbg("Fail to create AH for gid <0x%" PRIx64 ", 0x%" PRIx64 ">\n",
 229                    be64_to_cpu(dgid->global.subnet_prefix),
 230                    be64_to_cpu(dgid->global.interface_id));
 231        }
 232
 233        trace_create_ah_cache_miss(be64_to_cpu(dgid->global.subnet_prefix),
 234                                   be64_to_cpu(dgid->global.interface_id));
 235    }
 236
 237    return ah;
 238}
 239
 240static void destroy_ah_hash_key(gpointer data)
 241{
 242    g_bytes_unref(data);
 243}
 244
 245static void destroy_ah_hast_data(gpointer data)
 246{
 247    struct ibv_ah *ah = data;
 248
 249    ibv_destroy_ah(ah);
 250}
 251
 252static void ah_cache_init(void)
 253{
 254    ah_hash = g_hash_table_new_full(g_bytes_hash, g_bytes_equal,
 255                                    destroy_ah_hash_key, destroy_ah_hast_data);
 256}
 257
 258static int build_host_sge_array(RdmaDeviceResources *rdma_dev_res,
 259                                struct ibv_sge *dsge, struct ibv_sge *ssge,
 260                                uint8_t num_sge)
 261{
 262    RdmaRmMR *mr;
 263    int ssge_idx;
 264
 265    pr_dbg("num_sge=%d\n", num_sge);
 266
 267    for (ssge_idx = 0; ssge_idx < num_sge; ssge_idx++) {
 268        mr = rdma_rm_get_mr(rdma_dev_res, ssge[ssge_idx].lkey);
 269        if (unlikely(!mr)) {
 270            pr_dbg("Invalid lkey 0x%x\n", ssge[ssge_idx].lkey);
 271            return VENDOR_ERR_INVLKEY | ssge[ssge_idx].lkey;
 272        }
 273
 274        dsge->addr = (uintptr_t)mr->virt + ssge[ssge_idx].addr - mr->start;
 275        dsge->length = ssge[ssge_idx].length;
 276        dsge->lkey = rdma_backend_mr_lkey(&mr->backend_mr);
 277
 278        pr_dbg("ssge->addr=0x%" PRIx64 "\n", ssge[ssge_idx].addr);
 279        pr_dbg("dsge->addr=0x%" PRIx64 "\n", dsge->addr);
 280        pr_dbg("dsge->length=%d\n", dsge->length);
 281        pr_dbg("dsge->lkey=0x%x\n", dsge->lkey);
 282
 283        dsge++;
 284    }
 285
 286    return 0;
 287}
 288
 289void rdma_backend_post_send(RdmaBackendDev *backend_dev,
 290                            RdmaBackendQP *qp, uint8_t qp_type,
 291                            struct ibv_sge *sge, uint32_t num_sge,
 292                            union ibv_gid *dgid, uint32_t dqpn,
 293                            uint32_t dqkey, void *ctx)
 294{
 295    BackendCtx *bctx;
 296    struct ibv_sge new_sge[MAX_SGE];
 297    uint32_t bctx_id;
 298    int rc;
 299    struct ibv_send_wr wr = {0}, *bad_wr;
 300
 301    if (!qp->ibqp) { /* This field does not get initialized for QP0 and QP1 */
 302        if (qp_type == IBV_QPT_SMI) {
 303            pr_dbg("QP0 unsupported\n");
 304            comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_QP0, ctx);
 305        } else if (qp_type == IBV_QPT_GSI) {
 306            pr_dbg("QP1\n");
 307            comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_MAD_SEND, ctx);
 308        }
 309        pr_dbg("qp->ibqp is NULL for qp_type %d!!!\n", qp_type);
 310        return;
 311    }
 312
 313    pr_dbg("num_sge=%d\n", num_sge);
 314    if (!num_sge) {
 315        pr_dbg("num_sge=0\n");
 316        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_NO_SGE, ctx);
 317        return;
 318    }
 319
 320    bctx = g_malloc0(sizeof(*bctx));
 321    bctx->up_ctx = ctx;
 322    bctx->is_tx_req = 1;
 323
 324    rc = rdma_rm_alloc_cqe_ctx(backend_dev->rdma_dev_res, &bctx_id, bctx);
 325    if (unlikely(rc)) {
 326        pr_dbg("Failed to allocate cqe_ctx\n");
 327        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_NOMEM, ctx);
 328        goto out_free_bctx;
 329    }
 330
 331    rc = build_host_sge_array(backend_dev->rdma_dev_res, new_sge, sge, num_sge);
 332    if (rc) {
 333        pr_dbg("Error: Failed to build host SGE array\n");
 334        comp_handler(IBV_WC_GENERAL_ERR, rc, ctx);
 335        goto out_dealloc_cqe_ctx;
 336    }
 337
 338    if (qp_type == IBV_QPT_UD) {
 339        wr.wr.ud.ah = create_ah(backend_dev, qp->ibpd,
 340                                backend_dev->backend_gid_idx, dgid);
 341        wr.wr.ud.remote_qpn = dqpn;
 342        wr.wr.ud.remote_qkey = dqkey;
 343    }
 344
 345    wr.num_sge = num_sge;
 346    wr.opcode = IBV_WR_SEND;
 347    wr.send_flags = IBV_SEND_SIGNALED;
 348    wr.sg_list = new_sge;
 349    wr.wr_id = bctx_id;
 350
 351    rc = ibv_post_send(qp->ibqp, &wr, &bad_wr);
 352    pr_dbg("ibv_post_send=%d\n", rc);
 353    if (rc) {
 354        pr_dbg("Fail (%d, %d) to post send WQE to qpn %d\n", rc, errno,
 355                qp->ibqp->qp_num);
 356        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_FAIL_BACKEND, ctx);
 357        goto out_dealloc_cqe_ctx;
 358    }
 359
 360    return;
 361
 362out_dealloc_cqe_ctx:
 363    rdma_rm_dealloc_cqe_ctx(backend_dev->rdma_dev_res, bctx_id);
 364
 365out_free_bctx:
 366    g_free(bctx);
 367}
 368
 369void rdma_backend_post_recv(RdmaBackendDev *backend_dev,
 370                            RdmaDeviceResources *rdma_dev_res,
 371                            RdmaBackendQP *qp, uint8_t qp_type,
 372                            struct ibv_sge *sge, uint32_t num_sge, void *ctx)
 373{
 374    BackendCtx *bctx;
 375    struct ibv_sge new_sge[MAX_SGE];
 376    uint32_t bctx_id;
 377    int rc;
 378    struct ibv_recv_wr wr = {0}, *bad_wr;
 379
 380    if (!qp->ibqp) { /* This field does not get initialized for QP0 and QP1 */
 381        if (qp_type == IBV_QPT_SMI) {
 382            pr_dbg("QP0 unsupported\n");
 383            comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_QP0, ctx);
 384        }
 385        if (qp_type == IBV_QPT_GSI) {
 386            pr_dbg("QP1\n");
 387            comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_MAD_SEND, ctx);
 388        }
 389        return;
 390    }
 391
 392    pr_dbg("num_sge=%d\n", num_sge);
 393    if (!num_sge) {
 394        pr_dbg("num_sge=0\n");
 395        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_NO_SGE, ctx);
 396        return;
 397    }
 398
 399    bctx = g_malloc0(sizeof(*bctx));
 400    bctx->up_ctx = ctx;
 401    bctx->is_tx_req = 0;
 402
 403    rc = rdma_rm_alloc_cqe_ctx(rdma_dev_res, &bctx_id, bctx);
 404    if (unlikely(rc)) {
 405        pr_dbg("Failed to allocate cqe_ctx\n");
 406        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_NOMEM, ctx);
 407        goto out_free_bctx;
 408    }
 409
 410    rc = build_host_sge_array(rdma_dev_res, new_sge, sge, num_sge);
 411    if (rc) {
 412        pr_dbg("Error: Failed to build host SGE array\n");
 413        comp_handler(IBV_WC_GENERAL_ERR, rc, ctx);
 414        goto out_dealloc_cqe_ctx;
 415    }
 416
 417    wr.num_sge = num_sge;
 418    wr.sg_list = new_sge;
 419    wr.wr_id = bctx_id;
 420    rc = ibv_post_recv(qp->ibqp, &wr, &bad_wr);
 421    pr_dbg("ibv_post_recv=%d\n", rc);
 422    if (rc) {
 423        pr_dbg("Fail (%d, %d) to post recv WQE to qpn %d\n", rc, errno,
 424                qp->ibqp->qp_num);
 425        comp_handler(IBV_WC_GENERAL_ERR, VENDOR_ERR_FAIL_BACKEND, ctx);
 426        goto out_dealloc_cqe_ctx;
 427    }
 428
 429    return;
 430
 431out_dealloc_cqe_ctx:
 432    rdma_rm_dealloc_cqe_ctx(rdma_dev_res, bctx_id);
 433
 434out_free_bctx:
 435    g_free(bctx);
 436}
 437
 438int rdma_backend_create_pd(RdmaBackendDev *backend_dev, RdmaBackendPD *pd)
 439{
 440    pd->ibpd = ibv_alloc_pd(backend_dev->context);
 441
 442    return pd->ibpd ? 0 : -EIO;
 443}
 444
 445void rdma_backend_destroy_pd(RdmaBackendPD *pd)
 446{
 447    if (pd->ibpd) {
 448        ibv_dealloc_pd(pd->ibpd);
 449    }
 450}
 451
 452int rdma_backend_create_mr(RdmaBackendMR *mr, RdmaBackendPD *pd, void *addr,
 453                           size_t length, int access)
 454{
 455    pr_dbg("addr=0x%p\n", addr);
 456    pr_dbg("len=%zu\n", length);
 457    mr->ibmr = ibv_reg_mr(pd->ibpd, addr, length, access);
 458    if (mr->ibmr) {
 459        pr_dbg("lkey=0x%x\n", mr->ibmr->lkey);
 460        pr_dbg("rkey=0x%x\n", mr->ibmr->rkey);
 461        mr->ibpd = pd->ibpd;
 462    }
 463
 464    return mr->ibmr ? 0 : -EIO;
 465}
 466
 467void rdma_backend_destroy_mr(RdmaBackendMR *mr)
 468{
 469    if (mr->ibmr) {
 470        ibv_dereg_mr(mr->ibmr);
 471    }
 472}
 473
 474int rdma_backend_create_cq(RdmaBackendDev *backend_dev, RdmaBackendCQ *cq,
 475                           int cqe)
 476{
 477    int rc;
 478
 479    pr_dbg("cqe=%d\n", cqe);
 480
 481    pr_dbg("dev->channel=%p\n", backend_dev->channel);
 482    cq->ibcq = ibv_create_cq(backend_dev->context, cqe + 1, NULL,
 483                             backend_dev->channel, 0);
 484
 485    if (cq->ibcq) {
 486        rc = ibv_req_notify_cq(cq->ibcq, 0);
 487        if (rc) {
 488            pr_dbg("Error %d from ibv_req_notify_cq\n", rc);
 489        }
 490        cq->backend_dev = backend_dev;
 491    }
 492
 493    return cq->ibcq ? 0 : -EIO;
 494}
 495
 496void rdma_backend_destroy_cq(RdmaBackendCQ *cq)
 497{
 498    if (cq->ibcq) {
 499        ibv_destroy_cq(cq->ibcq);
 500    }
 501}
 502
 503int rdma_backend_create_qp(RdmaBackendQP *qp, uint8_t qp_type,
 504                           RdmaBackendPD *pd, RdmaBackendCQ *scq,
 505                           RdmaBackendCQ *rcq, uint32_t max_send_wr,
 506                           uint32_t max_recv_wr, uint32_t max_send_sge,
 507                           uint32_t max_recv_sge)
 508{
 509    struct ibv_qp_init_attr attr = {0};
 510
 511    qp->ibqp = 0;
 512    pr_dbg("qp_type=%d\n", qp_type);
 513
 514    switch (qp_type) {
 515    case IBV_QPT_GSI:
 516        pr_dbg("QP1 unsupported\n");
 517        return 0;
 518
 519    case IBV_QPT_RC:
 520        /* fall through */
 521    case IBV_QPT_UD:
 522        /* do nothing */
 523        break;
 524
 525    default:
 526        pr_dbg("Unsupported QP type %d\n", qp_type);
 527        return -EIO;
 528    }
 529
 530    attr.qp_type = qp_type;
 531    attr.send_cq = scq->ibcq;
 532    attr.recv_cq = rcq->ibcq;
 533    attr.cap.max_send_wr = max_send_wr;
 534    attr.cap.max_recv_wr = max_recv_wr;
 535    attr.cap.max_send_sge = max_send_sge;
 536    attr.cap.max_recv_sge = max_recv_sge;
 537
 538    pr_dbg("max_send_wr=%d\n", max_send_wr);
 539    pr_dbg("max_recv_wr=%d\n", max_recv_wr);
 540    pr_dbg("max_send_sge=%d\n", max_send_sge);
 541    pr_dbg("max_recv_sge=%d\n", max_recv_sge);
 542
 543    qp->ibqp = ibv_create_qp(pd->ibpd, &attr);
 544    if (likely(!qp->ibqp)) {
 545        pr_dbg("Error from ibv_create_qp\n");
 546        return -EIO;
 547    }
 548
 549    qp->ibpd = pd->ibpd;
 550
 551    /* TODO: Query QP to get max_inline_data and save it to be used in send */
 552
 553    pr_dbg("qpn=0x%x\n", qp->ibqp->qp_num);
 554
 555    return 0;
 556}
 557
 558int rdma_backend_qp_state_init(RdmaBackendDev *backend_dev, RdmaBackendQP *qp,
 559                               uint8_t qp_type, uint32_t qkey)
 560{
 561    struct ibv_qp_attr attr = {0};
 562    int rc, attr_mask;
 563
 564    pr_dbg("qpn=0x%x\n", qp->ibqp->qp_num);
 565    pr_dbg("sport_num=%d\n", backend_dev->port_num);
 566
 567    attr_mask = IBV_QP_STATE | IBV_QP_PKEY_INDEX | IBV_QP_PORT;
 568    attr.qp_state        = IBV_QPS_INIT;
 569    attr.pkey_index      = 0;
 570    attr.port_num        = backend_dev->port_num;
 571
 572    switch (qp_type) {
 573    case IBV_QPT_RC:
 574        attr_mask |= IBV_QP_ACCESS_FLAGS;
 575        break;
 576
 577    case IBV_QPT_UD:
 578        attr.qkey = qkey;
 579        attr_mask |= IBV_QP_QKEY;
 580        break;
 581
 582    default:
 583        pr_dbg("Unsupported QP type %d\n", qp_type);
 584        return -EIO;
 585    }
 586
 587    rc = ibv_modify_qp(qp->ibqp, &attr, attr_mask);
 588    if (rc) {
 589        pr_dbg("Error %d from ibv_modify_qp\n", rc);
 590        return -EIO;
 591    }
 592
 593    return 0;
 594}
 595
 596int rdma_backend_qp_state_rtr(RdmaBackendDev *backend_dev, RdmaBackendQP *qp,
 597                              uint8_t qp_type, union ibv_gid *dgid,
 598                              uint32_t dqpn, uint32_t rq_psn, uint32_t qkey,
 599                              bool use_qkey)
 600{
 601    struct ibv_qp_attr attr = {0};
 602    union ibv_gid ibv_gid = {
 603        .global.interface_id = dgid->global.interface_id,
 604        .global.subnet_prefix = dgid->global.subnet_prefix
 605    };
 606    int rc, attr_mask;
 607
 608    attr.qp_state = IBV_QPS_RTR;
 609    attr_mask = IBV_QP_STATE;
 610
 611    switch (qp_type) {
 612    case IBV_QPT_RC:
 613        pr_dbg("dgid=0x%" PRIx64 ",%" PRIx64 "\n",
 614               be64_to_cpu(ibv_gid.global.subnet_prefix),
 615               be64_to_cpu(ibv_gid.global.interface_id));
 616        pr_dbg("dqpn=0x%x\n", dqpn);
 617        pr_dbg("sgid_idx=%d\n", backend_dev->backend_gid_idx);
 618        pr_dbg("sport_num=%d\n", backend_dev->port_num);
 619        pr_dbg("rq_psn=0x%x\n", rq_psn);
 620
 621        attr.path_mtu               = IBV_MTU_1024;
 622        attr.dest_qp_num            = dqpn;
 623        attr.max_dest_rd_atomic     = 1;
 624        attr.min_rnr_timer          = 12;
 625        attr.ah_attr.port_num       = backend_dev->port_num;
 626        attr.ah_attr.is_global      = 1;
 627        attr.ah_attr.grh.hop_limit  = 1;
 628        attr.ah_attr.grh.dgid       = ibv_gid;
 629        attr.ah_attr.grh.sgid_index = backend_dev->backend_gid_idx;
 630        attr.rq_psn                 = rq_psn;
 631
 632        attr_mask |= IBV_QP_AV | IBV_QP_PATH_MTU | IBV_QP_DEST_QPN |
 633                     IBV_QP_RQ_PSN | IBV_QP_MAX_DEST_RD_ATOMIC |
 634                     IBV_QP_MIN_RNR_TIMER;
 635        break;
 636
 637    case IBV_QPT_UD:
 638        if (use_qkey) {
 639            pr_dbg("qkey=0x%x\n", qkey);
 640            attr.qkey = qkey;
 641            attr_mask |= IBV_QP_QKEY;
 642        }
 643        break;
 644    }
 645
 646    rc = ibv_modify_qp(qp->ibqp, &attr, attr_mask);
 647    if (rc) {
 648        pr_dbg("Error %d from ibv_modify_qp\n", rc);
 649        return -EIO;
 650    }
 651
 652    return 0;
 653}
 654
 655int rdma_backend_qp_state_rts(RdmaBackendQP *qp, uint8_t qp_type,
 656                              uint32_t sq_psn, uint32_t qkey, bool use_qkey)
 657{
 658    struct ibv_qp_attr attr = {0};
 659    int rc, attr_mask;
 660
 661    pr_dbg("qpn=0x%x\n", qp->ibqp->qp_num);
 662    pr_dbg("sq_psn=0x%x\n", sq_psn);
 663
 664    attr.qp_state = IBV_QPS_RTS;
 665    attr.sq_psn = sq_psn;
 666    attr_mask = IBV_QP_STATE | IBV_QP_SQ_PSN;
 667
 668    switch (qp_type) {
 669    case IBV_QPT_RC:
 670        attr.timeout       = 14;
 671        attr.retry_cnt     = 7;
 672        attr.rnr_retry     = 7;
 673        attr.max_rd_atomic = 1;
 674
 675        attr_mask |= IBV_QP_TIMEOUT | IBV_QP_RETRY_CNT | IBV_QP_RNR_RETRY |
 676                     IBV_QP_MAX_QP_RD_ATOMIC;
 677        break;
 678
 679    case IBV_QPT_UD:
 680        if (use_qkey) {
 681            pr_dbg("qkey=0x%x\n", qkey);
 682            attr.qkey = qkey;
 683            attr_mask |= IBV_QP_QKEY;
 684        }
 685        break;
 686    }
 687
 688    rc = ibv_modify_qp(qp->ibqp, &attr, attr_mask);
 689    if (rc) {
 690        pr_dbg("Error %d from ibv_modify_qp\n", rc);
 691        return -EIO;
 692    }
 693
 694    return 0;
 695}
 696
 697int rdma_backend_query_qp(RdmaBackendQP *qp, struct ibv_qp_attr *attr,
 698                          int attr_mask, struct ibv_qp_init_attr *init_attr)
 699{
 700    if (!qp->ibqp) {
 701        pr_dbg("QP1\n");
 702        attr->qp_state = IBV_QPS_RTS;
 703        return 0;
 704    }
 705
 706    return ibv_query_qp(qp->ibqp, attr, attr_mask, init_attr);
 707}
 708
 709void rdma_backend_destroy_qp(RdmaBackendQP *qp)
 710{
 711    if (qp->ibqp) {
 712        ibv_destroy_qp(qp->ibqp);
 713    }
 714}
 715
 716#define CHK_ATTR(req, dev, member, fmt) ({ \
 717    pr_dbg("%s="fmt","fmt"\n", #member, dev.member, req->member); \
 718    if (req->member > dev.member) { \
 719        warn_report("%s = "fmt" is higher than host device capability "fmt, \
 720                    #member, req->member, dev.member); \
 721        req->member = dev.member; \
 722    } \
 723    pr_dbg("%s="fmt"\n", #member, req->member); })
 724
 725static int init_device_caps(RdmaBackendDev *backend_dev,
 726                            struct ibv_device_attr *dev_attr)
 727{
 728    if (ibv_query_device(backend_dev->context, &backend_dev->dev_attr)) {
 729        return -EIO;
 730    }
 731
 732    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_mr_size, "%" PRId64);
 733    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_qp, "%d");
 734    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_sge, "%d");
 735    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_qp_wr, "%d");
 736    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_cq, "%d");
 737    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_cqe, "%d");
 738    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_mr, "%d");
 739    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_pd, "%d");
 740    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_qp_rd_atom, "%d");
 741    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_qp_init_rd_atom, "%d");
 742    CHK_ATTR(dev_attr, backend_dev->dev_attr, max_ah, "%d");
 743
 744    return 0;
 745}
 746
 747int rdma_backend_init(RdmaBackendDev *backend_dev, PCIDevice *pdev,
 748                      RdmaDeviceResources *rdma_dev_res,
 749                      const char *backend_device_name, uint8_t port_num,
 750                      uint8_t backend_gid_idx, struct ibv_device_attr *dev_attr,
 751                      Error **errp)
 752{
 753    int i;
 754    int ret = 0;
 755    int num_ibv_devices;
 756    struct ibv_device **dev_list;
 757    struct ibv_port_attr port_attr;
 758
 759    memset(backend_dev, 0, sizeof(*backend_dev));
 760
 761    backend_dev->dev = pdev;
 762
 763    backend_dev->backend_gid_idx = backend_gid_idx;
 764    backend_dev->port_num = port_num;
 765    backend_dev->rdma_dev_res = rdma_dev_res;
 766
 767    rdma_backend_register_comp_handler(dummy_comp_handler);
 768
 769    dev_list = ibv_get_device_list(&num_ibv_devices);
 770    if (!dev_list) {
 771        error_setg(errp, "Failed to get IB devices list");
 772        return -EIO;
 773    }
 774
 775    if (num_ibv_devices == 0) {
 776        error_setg(errp, "No IB devices were found");
 777        ret = -ENXIO;
 778        goto out_free_dev_list;
 779    }
 780
 781    if (backend_device_name) {
 782        for (i = 0; dev_list[i]; ++i) {
 783            if (!strcmp(ibv_get_device_name(dev_list[i]),
 784                        backend_device_name)) {
 785                break;
 786            }
 787        }
 788
 789        backend_dev->ib_dev = dev_list[i];
 790        if (!backend_dev->ib_dev) {
 791            error_setg(errp, "Failed to find IB device %s",
 792                       backend_device_name);
 793            ret = -EIO;
 794            goto out_free_dev_list;
 795        }
 796    } else {
 797        backend_dev->ib_dev = *dev_list;
 798    }
 799
 800    pr_dbg("Using backend device %s, port %d, gid_idx %d\n",
 801           ibv_get_device_name(backend_dev->ib_dev),
 802           backend_dev->port_num, backend_dev->backend_gid_idx);
 803
 804    backend_dev->context = ibv_open_device(backend_dev->ib_dev);
 805    if (!backend_dev->context) {
 806        error_setg(errp, "Failed to open IB device");
 807        ret = -EIO;
 808        goto out;
 809    }
 810
 811    backend_dev->channel = ibv_create_comp_channel(backend_dev->context);
 812    if (!backend_dev->channel) {
 813        error_setg(errp, "Failed to create IB communication channel");
 814        ret = -EIO;
 815        goto out_close_device;
 816    }
 817    pr_dbg("dev->backend_dev.channel=%p\n", backend_dev->channel);
 818
 819    ret = ibv_query_port(backend_dev->context, backend_dev->port_num,
 820                         &port_attr);
 821    if (ret) {
 822        error_setg(errp, "Error %d from ibv_query_port", ret);
 823        ret = -EIO;
 824        goto out_destroy_comm_channel;
 825    }
 826
 827    if (backend_dev->backend_gid_idx >= port_attr.gid_tbl_len) {
 828        error_setg(errp, "Invalid backend_gid_idx, should be less than %d",
 829                   port_attr.gid_tbl_len);
 830        goto out_destroy_comm_channel;
 831    }
 832
 833    ret = init_device_caps(backend_dev, dev_attr);
 834    if (ret) {
 835        error_setg(errp, "Failed to initialize device capabilities");
 836        ret = -EIO;
 837        goto out_destroy_comm_channel;
 838    }
 839
 840    ret = ibv_query_gid(backend_dev->context, backend_dev->port_num,
 841                         backend_dev->backend_gid_idx, &backend_dev->gid);
 842    if (ret) {
 843        error_setg(errp, "Failed to query gid %d",
 844                   backend_dev->backend_gid_idx);
 845        ret = -EIO;
 846        goto out_destroy_comm_channel;
 847    }
 848    pr_dbg("subnet_prefix=0x%" PRIx64 "\n",
 849           be64_to_cpu(backend_dev->gid.global.subnet_prefix));
 850    pr_dbg("interface_id=0x%" PRIx64 "\n",
 851           be64_to_cpu(backend_dev->gid.global.interface_id));
 852
 853    backend_dev->comp_thread.run = false;
 854    backend_dev->comp_thread.is_running = false;
 855
 856    ah_cache_init();
 857
 858    goto out_free_dev_list;
 859
 860out_destroy_comm_channel:
 861    ibv_destroy_comp_channel(backend_dev->channel);
 862
 863out_close_device:
 864    ibv_close_device(backend_dev->context);
 865
 866out_free_dev_list:
 867    ibv_free_device_list(dev_list);
 868
 869out:
 870    return ret;
 871}
 872
 873
 874void rdma_backend_start(RdmaBackendDev *backend_dev)
 875{
 876    pr_dbg("Starting rdma_backend\n");
 877    start_comp_thread(backend_dev);
 878}
 879
 880void rdma_backend_stop(RdmaBackendDev *backend_dev)
 881{
 882    pr_dbg("Stopping rdma_backend\n");
 883    stop_backend_thread(&backend_dev->comp_thread);
 884}
 885
 886void rdma_backend_fini(RdmaBackendDev *backend_dev)
 887{
 888    rdma_backend_stop(backend_dev);
 889    g_hash_table_destroy(ah_hash);
 890    ibv_destroy_comp_channel(backend_dev->channel);
 891    ibv_close_device(backend_dev->context);
 892}
 893