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-rw-r--r--hw/rdma/rdma_backend.c1401
1 files changed, 0 insertions, 1401 deletions
diff --git a/hw/rdma/rdma_backend.c b/hw/rdma/rdma_backend.c
deleted file mode 100644
index 6dcdfbbbe2..0000000000
--- a/hw/rdma/rdma_backend.c
+++ /dev/null
@@ -1,1401 +0,0 @@
-/*
- * QEMU paravirtual RDMA - Generic RDMA backend
- *
- * Copyright (C) 2018 Oracle
- * Copyright (C) 2018 Red Hat Inc
- *
- * Authors:
- *     Yuval Shaia <yuval.shaia@oracle.com>
- *     Marcel Apfelbaum <marcel@redhat.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or later.
- * See the COPYING file in the top-level directory.
- *
- */
-
-#include "qemu/osdep.h"
-#include "qapi/qapi-events-rdma.h"
-
-#include <infiniband/verbs.h>
-
-#include "contrib/rdmacm-mux/rdmacm-mux.h"
-#include "trace.h"
-#include "rdma_utils.h"
-#include "rdma_rm.h"
-#include "rdma_backend.h"
-
-#define THR_NAME_LEN 16
-#define THR_POLL_TO  5000
-
-#define MAD_HDR_SIZE sizeof(struct ibv_grh)
-
-typedef struct BackendCtx {
-    void *up_ctx;
-    struct ibv_sge sge; /* Used to save MAD recv buffer */
-    RdmaBackendQP *backend_qp; /* To maintain recv buffers */
-    RdmaBackendSRQ *backend_srq;
-} BackendCtx;
-
-struct backend_umad {
-    struct ib_user_mad hdr;
-    char mad[RDMA_MAX_PRIVATE_DATA];
-};
-
-static void (*comp_handler)(void *ctx, struct ibv_wc *wc);
-
-static void dummy_comp_handler(void *ctx, struct ibv_wc *wc)
-{
-    rdma_error_report("No completion handler is registered");
-}
-
-static inline void complete_work(enum ibv_wc_status status, uint32_t vendor_err,
-                                 void *ctx)
-{
-    struct ibv_wc wc = {};
-
-    wc.status = status;
-    wc.vendor_err = vendor_err;
-
-    comp_handler(ctx, &wc);
-}
-
-static void free_cqe_ctx(gpointer data, gpointer user_data)
-{
-    BackendCtx *bctx;
-    RdmaDeviceResources *rdma_dev_res = user_data;
-    unsigned long cqe_ctx_id = GPOINTER_TO_INT(data);
-
-    bctx = rdma_rm_get_cqe_ctx(rdma_dev_res, cqe_ctx_id);
-    if (bctx) {
-        rdma_rm_dealloc_cqe_ctx(rdma_dev_res, cqe_ctx_id);
-        qatomic_dec(&rdma_dev_res->stats.missing_cqe);
-    }
-    g_free(bctx);
-}
-
-static void clean_recv_mads(RdmaBackendDev *backend_dev)
-{
-    unsigned long cqe_ctx_id;
-
-    do {
-        cqe_ctx_id = rdma_protected_gqueue_pop_int64(&backend_dev->
-                                                    recv_mads_list);
-        if (cqe_ctx_id != -ENOENT) {
-            qatomic_inc(&backend_dev->rdma_dev_res->stats.missing_cqe);
-            free_cqe_ctx(GINT_TO_POINTER(cqe_ctx_id),
-                         backend_dev->rdma_dev_res);
-        }
-    } while (cqe_ctx_id != -ENOENT);
-}
-
-static int rdma_poll_cq(RdmaDeviceResources *rdma_dev_res, struct ibv_cq *ibcq)
-{
-    int i, ne, total_ne = 0;
-    BackendCtx *bctx;
-    struct ibv_wc wc[2];
-    RdmaProtectedGSList *cqe_ctx_list;
-
-    WITH_QEMU_LOCK_GUARD(&rdma_dev_res->lock) {
-        do {
-            ne = ibv_poll_cq(ibcq, ARRAY_SIZE(wc), wc);
-
-            trace_rdma_poll_cq(ne, ibcq);
-
-            for (i = 0; i < ne; i++) {
-                bctx = rdma_rm_get_cqe_ctx(rdma_dev_res, wc[i].wr_id);
-                if (unlikely(!bctx)) {
-                    rdma_error_report("No matching ctx for req %"PRId64,
-                                      wc[i].wr_id);
-                    continue;
-                }
-
-                comp_handler(bctx->up_ctx, &wc[i]);
-
-                if (bctx->backend_qp) {
-                    cqe_ctx_list = &bctx->backend_qp->cqe_ctx_list;
-                } else {
-                    cqe_ctx_list = &bctx->backend_srq->cqe_ctx_list;
-                }
-
-                rdma_protected_gslist_remove_int32(cqe_ctx_list, wc[i].wr_id);
-                rdma_rm_dealloc_cqe_ctx(rdma_dev_res, wc[i].wr_id);
-                g_free(bctx);
-            }
-            total_ne += ne;
-        } while (ne > 0);
-        qatomic_sub(&rdma_dev_res->stats.missing_cqe, total_ne);
-    }
-
-    if (ne < 0) {
-        rdma_error_report("ibv_poll_cq fail, rc=%d, errno=%d", ne, errno);
-    }
-
-    rdma_dev_res->stats.completions += total_ne;
-
-    return total_ne;
-}
-
-static void *comp_handler_thread(void *arg)
-{
-    RdmaBackendDev *backend_dev = (RdmaBackendDev *)arg;
-    int rc;
-    struct ibv_cq *ev_cq;
-    void *ev_ctx;
-    int flags;
-    GPollFD pfds[1];
-
-    /* Change to non-blocking mode */
-    flags = fcntl(backend_dev->channel->fd, F_GETFL);
-    rc = fcntl(backend_dev->channel->fd, F_SETFL, flags | O_NONBLOCK);
-    if (rc < 0) {
-        rdma_error_report("Failed to change backend channel FD to non-blocking");
-        return NULL;
-    }
-
-    pfds[0].fd = backend_dev->channel->fd;
-    pfds[0].events = G_IO_IN | G_IO_HUP | G_IO_ERR;
-
-    backend_dev->comp_thread.is_running = true;
-
-    while (backend_dev->comp_thread.run) {
-        do {
-            rc = qemu_poll_ns(pfds, 1, THR_POLL_TO * (int64_t)SCALE_MS);
-            if (!rc) {
-                backend_dev->rdma_dev_res->stats.poll_cq_ppoll_to++;
-            }
-        } while (!rc && backend_dev->comp_thread.run);
-
-        if (backend_dev->comp_thread.run) {
-            rc = ibv_get_cq_event(backend_dev->channel, &ev_cq, &ev_ctx);
-            if (unlikely(rc)) {
-                rdma_error_report("ibv_get_cq_event fail, rc=%d, errno=%d", rc,
-                                  errno);
-                continue;
-            }
-
-            rc = ibv_req_notify_cq(ev_cq, 0);
-            if (unlikely(rc)) {
-                rdma_error_report("ibv_req_notify_cq fail, rc=%d, errno=%d", rc,
-                                  errno);
-            }
-
-            backend_dev->rdma_dev_res->stats.poll_cq_from_bk++;
-            rdma_poll_cq(backend_dev->rdma_dev_res, ev_cq);
-
-            ibv_ack_cq_events(ev_cq, 1);
-        }
-    }
-
-    backend_dev->comp_thread.is_running = false;
-
-    qemu_thread_exit(0);
-
-    return NULL;
-}
-
-static inline void disable_rdmacm_mux_async(RdmaBackendDev *backend_dev)
-{
-    qatomic_set(&backend_dev->rdmacm_mux.can_receive, 0);
-}
-
-static inline void enable_rdmacm_mux_async(RdmaBackendDev *backend_dev)
-{
-    qatomic_set(&backend_dev->rdmacm_mux.can_receive, sizeof(RdmaCmMuxMsg));
-}
-
-static inline int rdmacm_mux_can_process_async(RdmaBackendDev *backend_dev)
-{
-    return qatomic_read(&backend_dev->rdmacm_mux.can_receive);
-}
-
-static int rdmacm_mux_check_op_status(CharBackend *mad_chr_be)
-{
-    RdmaCmMuxMsg msg = {};
-    int ret;
-
-    ret = qemu_chr_fe_read_all(mad_chr_be, (uint8_t *)&msg, sizeof(msg));
-    if (ret != sizeof(msg)) {
-        rdma_error_report("Got invalid message from mux: size %d, expecting %d",
-                          ret, (int)sizeof(msg));
-        return -EIO;
-    }
-
-    trace_rdmacm_mux_check_op_status(msg.hdr.msg_type, msg.hdr.op_code,
-                                     msg.hdr.err_code);
-
-    if (msg.hdr.msg_type != RDMACM_MUX_MSG_TYPE_RESP) {
-        rdma_error_report("Got invalid message type %d", msg.hdr.msg_type);
-        return -EIO;
-    }
-
-    if (msg.hdr.err_code != RDMACM_MUX_ERR_CODE_OK) {
-        rdma_error_report("Operation failed in mux, error code %d",
-                          msg.hdr.err_code);
-        return -EIO;
-    }
-
-    return 0;
-}
-
-static int rdmacm_mux_send(RdmaBackendDev *backend_dev, RdmaCmMuxMsg *msg)
-{
-    int rc = 0;
-
-    msg->hdr.msg_type = RDMACM_MUX_MSG_TYPE_REQ;
-    trace_rdmacm_mux("send", msg->hdr.msg_type, msg->hdr.op_code);
-    disable_rdmacm_mux_async(backend_dev);
-    rc = qemu_chr_fe_write(backend_dev->rdmacm_mux.chr_be,
-                           (const uint8_t *)msg, sizeof(*msg));
-    if (rc != sizeof(*msg)) {
-        enable_rdmacm_mux_async(backend_dev);
-        rdma_error_report("Failed to send request to rdmacm_mux (rc=%d)", rc);
-        return -EIO;
-    }
-
-    rc = rdmacm_mux_check_op_status(backend_dev->rdmacm_mux.chr_be);
-    if (rc) {
-        rdma_error_report("Failed to execute rdmacm_mux request %d (rc=%d)",
-                          msg->hdr.op_code, rc);
-    }
-
-    enable_rdmacm_mux_async(backend_dev);
-
-    return 0;
-}
-
-static void stop_backend_thread(RdmaBackendThread *thread)
-{
-    thread->run = false;
-    while (thread->is_running) {
-        sleep(THR_POLL_TO / SCALE_US / 2);
-    }
-}
-
-static void start_comp_thread(RdmaBackendDev *backend_dev)
-{
-    char thread_name[THR_NAME_LEN] = {};
-
-    stop_backend_thread(&backend_dev->comp_thread);
-
-    snprintf(thread_name, sizeof(thread_name), "rdma_comp_%s",
-             ibv_get_device_name(backend_dev->ib_dev));
-    backend_dev->comp_thread.run = true;
-    qemu_thread_create(&backend_dev->comp_thread.thread, thread_name,
-                       comp_handler_thread, backend_dev, QEMU_THREAD_DETACHED);
-}
-
-void rdma_backend_register_comp_handler(void (*handler)(void *ctx,
-                                                         struct ibv_wc *wc))
-{
-    comp_handler = handler;
-}
-
-void rdma_backend_unregister_comp_handler(void)
-{
-    rdma_backend_register_comp_handler(dummy_comp_handler);
-}
-
-int rdma_backend_query_port(RdmaBackendDev *backend_dev,
-                            struct ibv_port_attr *port_attr)
-{
-    int rc;
-
-    rc = ibv_query_port(backend_dev->context, backend_dev->port_num, port_attr);
-    if (rc) {
-        rdma_error_report("ibv_query_port fail, rc=%d, errno=%d", rc, errno);
-        return -EIO;
-    }
-
-    return 0;
-}
-
-void rdma_backend_poll_cq(RdmaDeviceResources *rdma_dev_res, RdmaBackendCQ *cq)
-{
-    int polled;
-
-    rdma_dev_res->stats.poll_cq_from_guest++;
-    polled = rdma_poll_cq(rdma_dev_res, cq->ibcq);
-    if (!polled) {
-        rdma_dev_res->stats.poll_cq_from_guest_empty++;
-    }
-}
-
-static GHashTable *ah_hash;
-
-static struct ibv_ah *create_ah(RdmaBackendDev *backend_dev, struct ibv_pd *pd,
-                                uint8_t sgid_idx, union ibv_gid *dgid)
-{
-    GBytes *ah_key = g_bytes_new(dgid, sizeof(*dgid));
-    struct ibv_ah *ah = g_hash_table_lookup(ah_hash, ah_key);
-
-    if (ah) {
-        trace_rdma_create_ah_cache_hit(be64_to_cpu(dgid->global.subnet_prefix),
-                                       be64_to_cpu(dgid->global.interface_id));
-        g_bytes_unref(ah_key);
-    } else {
-        struct ibv_ah_attr ah_attr = {
-            .is_global     = 1,
-            .port_num      = backend_dev->port_num,
-            .grh.hop_limit = 1,
-        };
-
-        ah_attr.grh.dgid = *dgid;
-        ah_attr.grh.sgid_index = sgid_idx;
-
-        ah = ibv_create_ah(pd, &ah_attr);
-        if (ah) {
-            g_hash_table_insert(ah_hash, ah_key, ah);
-        } else {
-            g_bytes_unref(ah_key);
-            rdma_error_report("Failed to create AH for gid <0x%" PRIx64", 0x%"PRIx64">",
-                              be64_to_cpu(dgid->global.subnet_prefix),
-                              be64_to_cpu(dgid->global.interface_id));
-        }
-
-        trace_rdma_create_ah_cache_miss(be64_to_cpu(dgid->global.subnet_prefix),
-                                        be64_to_cpu(dgid->global.interface_id));
-    }
-
-    return ah;
-}
-
-static void destroy_ah_hash_key(gpointer data)
-{
-    g_bytes_unref(data);
-}
-
-static void destroy_ah_hast_data(gpointer data)
-{
-    struct ibv_ah *ah = data;
-
-    ibv_destroy_ah(ah);
-}
-
-static void ah_cache_init(void)
-{
-    ah_hash = g_hash_table_new_full(g_bytes_hash, g_bytes_equal,
-                                    destroy_ah_hash_key, destroy_ah_hast_data);
-}
-
-#ifdef LEGACY_RDMA_REG_MR
-static int build_host_sge_array(RdmaDeviceResources *rdma_dev_res,
-                                struct ibv_sge *sge, uint8_t num_sge,
-                                uint64_t *total_length)
-{
-    RdmaRmMR *mr;
-    int idx;
-
-    for (idx = 0; idx < num_sge; idx++) {
-        mr = rdma_rm_get_mr(rdma_dev_res, sge[idx].lkey);
-        if (unlikely(!mr)) {
-            rdma_error_report("Invalid lkey 0x%x", sge[idx].lkey);
-            return VENDOR_ERR_INVLKEY | sge[idx].lkey;
-        }
-
-        sge[idx].addr = (uintptr_t)mr->virt + sge[idx].addr - mr->start;
-        sge[idx].lkey = rdma_backend_mr_lkey(&mr->backend_mr);
-
-        *total_length += sge[idx].length;
-    }
-
-    return 0;
-}
-#else
-static inline int build_host_sge_array(RdmaDeviceResources *rdma_dev_res,
-                                       struct ibv_sge *sge, uint8_t num_sge,
-                                       uint64_t *total_length)
-{
-    int idx;
-
-    for (idx = 0; idx < num_sge; idx++) {
-        *total_length += sge[idx].length;
-    }
-    return 0;
-}
-#endif
-
-static void trace_mad_message(const char *title, char *buf, int len)
-{
-    int i;
-    char *b = g_malloc0(len * 3 + 1);
-    char b1[4];
-
-    for (i = 0; i < len; i++) {
-        sprintf(b1, "%.2X ", buf[i] & 0x000000FF);
-        strcat(b, b1);
-    }
-
-    trace_rdma_mad_message(title, len, b);
-
-    g_free(b);
-}
-
-static int mad_send(RdmaBackendDev *backend_dev, uint8_t sgid_idx,
-                    union ibv_gid *sgid, struct ibv_sge *sge, uint32_t num_sge)
-{
-    RdmaCmMuxMsg msg = {};
-    char *hdr, *data;
-    int ret;
-
-    if (num_sge != 2) {
-        return -EINVAL;
-    }
-
-    msg.hdr.op_code = RDMACM_MUX_OP_CODE_MAD;
-    memcpy(msg.hdr.sgid.raw, sgid->raw, sizeof(msg.hdr.sgid));
-
-    msg.umad_len = sge[0].length + sge[1].length;
-
-    if (msg.umad_len > sizeof(msg.umad.mad)) {
-        return -ENOMEM;
-    }
-
-    msg.umad.hdr.addr.qpn = htobe32(1);
-    msg.umad.hdr.addr.grh_present = 1;
-    msg.umad.hdr.addr.gid_index = sgid_idx;
-    memcpy(msg.umad.hdr.addr.gid, sgid->raw, sizeof(msg.umad.hdr.addr.gid));
-    msg.umad.hdr.addr.hop_limit = 0xFF;
-
-    hdr = rdma_pci_dma_map(backend_dev->dev, sge[0].addr, sge[0].length);
-    if (!hdr) {
-        return -ENOMEM;
-    }
-    data = rdma_pci_dma_map(backend_dev->dev, sge[1].addr, sge[1].length);
-    if (!data) {
-        rdma_pci_dma_unmap(backend_dev->dev, hdr, sge[0].length);
-        return -ENOMEM;
-    }
-
-    memcpy(&msg.umad.mad[0], hdr, sge[0].length);
-    memcpy(&msg.umad.mad[sge[0].length], data, sge[1].length);
-
-    rdma_pci_dma_unmap(backend_dev->dev, data, sge[1].length);
-    rdma_pci_dma_unmap(backend_dev->dev, hdr, sge[0].length);
-
-    trace_mad_message("send", msg.umad.mad, msg.umad_len);
-
-    ret = rdmacm_mux_send(backend_dev, &msg);
-    if (ret) {
-        rdma_error_report("Failed to send MAD to rdma_umadmux (%d)", ret);
-        return -EIO;
-    }
-
-    return 0;
-}
-
-void rdma_backend_post_send(RdmaBackendDev *backend_dev,
-                            RdmaBackendQP *qp, uint8_t qp_type,
-                            struct ibv_sge *sge, uint32_t num_sge,
-                            uint8_t sgid_idx, union ibv_gid *sgid,
-                            union ibv_gid *dgid, uint32_t dqpn, uint32_t dqkey,
-                            void *ctx)
-{
-    BackendCtx *bctx;
-    uint32_t bctx_id;
-    int rc;
-    struct ibv_send_wr wr = {}, *bad_wr;
-
-    if (!qp->ibqp) { /* This field is not initialized for QP0 and QP1 */
-        if (qp_type == IBV_QPT_SMI) {
-            rdma_error_report("Got QP0 request");
-            complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_QP0, ctx);
-        } else if (qp_type == IBV_QPT_GSI) {
-            rc = mad_send(backend_dev, sgid_idx, sgid, sge, num_sge);
-            if (rc) {
-                complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_MAD_SEND, ctx);
-                backend_dev->rdma_dev_res->stats.mad_tx_err++;
-            } else {
-                complete_work(IBV_WC_SUCCESS, 0, ctx);
-                backend_dev->rdma_dev_res->stats.mad_tx++;
-            }
-        }
-        return;
-    }
-
-    bctx = g_malloc0(sizeof(*bctx));
-    bctx->up_ctx = ctx;
-    bctx->backend_qp = qp;
-
-    rc = rdma_rm_alloc_cqe_ctx(backend_dev->rdma_dev_res, &bctx_id, bctx);
-    if (unlikely(rc)) {
-        complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_NOMEM, ctx);
-        goto err_free_bctx;
-    }
-
-    rdma_protected_gslist_append_int32(&qp->cqe_ctx_list, bctx_id);
-
-    rc = build_host_sge_array(backend_dev->rdma_dev_res, sge, num_sge,
-                              &backend_dev->rdma_dev_res->stats.tx_len);
-    if (rc) {
-        complete_work(IBV_WC_GENERAL_ERR, rc, ctx);
-        goto err_dealloc_cqe_ctx;
-    }
-
-    if (qp_type == IBV_QPT_UD) {
-        wr.wr.ud.ah = create_ah(backend_dev, qp->ibpd, sgid_idx, dgid);
-        if (!wr.wr.ud.ah) {
-            complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_FAIL_BACKEND, ctx);
-            goto err_dealloc_cqe_ctx;
-        }
-        wr.wr.ud.remote_qpn = dqpn;
-        wr.wr.ud.remote_qkey = dqkey;
-    }
-
-    wr.num_sge = num_sge;
-    wr.opcode = IBV_WR_SEND;
-    wr.send_flags = IBV_SEND_SIGNALED;
-    wr.sg_list = sge;
-    wr.wr_id = bctx_id;
-
-    rc = ibv_post_send(qp->ibqp, &wr, &bad_wr);
-    if (rc) {
-        rdma_error_report("ibv_post_send fail, qpn=0x%x, rc=%d, errno=%d",
-                          qp->ibqp->qp_num, rc, errno);
-        complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_FAIL_BACKEND, ctx);
-        goto err_dealloc_cqe_ctx;
-    }
-
-    qatomic_inc(&backend_dev->rdma_dev_res->stats.missing_cqe);
-    backend_dev->rdma_dev_res->stats.tx++;
-
-    return;
-
-err_dealloc_cqe_ctx:
-    backend_dev->rdma_dev_res->stats.tx_err++;
-    rdma_rm_dealloc_cqe_ctx(backend_dev->rdma_dev_res, bctx_id);
-
-err_free_bctx:
-    g_free(bctx);
-}
-
-static unsigned int save_mad_recv_buffer(RdmaBackendDev *backend_dev,
-                                         struct ibv_sge *sge, uint32_t num_sge,
-                                         void *ctx)
-{
-    BackendCtx *bctx;
-    int rc;
-    uint32_t bctx_id;
-
-    if (num_sge != 1) {
-        rdma_error_report("Invalid num_sge (%d), expecting 1", num_sge);
-        return VENDOR_ERR_INV_NUM_SGE;
-    }
-
-    if (sge[0].length < RDMA_MAX_PRIVATE_DATA + sizeof(struct ibv_grh)) {
-        rdma_error_report("Too small buffer for MAD");
-        return VENDOR_ERR_INV_MAD_BUFF;
-    }
-
-    bctx = g_malloc0(sizeof(*bctx));
-
-    rc = rdma_rm_alloc_cqe_ctx(backend_dev->rdma_dev_res, &bctx_id, bctx);
-    if (unlikely(rc)) {
-        g_free(bctx);
-        return VENDOR_ERR_NOMEM;
-    }
-
-    bctx->up_ctx = ctx;
-    bctx->sge = *sge;
-
-    rdma_protected_gqueue_append_int64(&backend_dev->recv_mads_list, bctx_id);
-
-    return 0;
-}
-
-void rdma_backend_post_recv(RdmaBackendDev *backend_dev,
-                            RdmaBackendQP *qp, uint8_t qp_type,
-                            struct ibv_sge *sge, uint32_t num_sge, void *ctx)
-{
-    BackendCtx *bctx;
-    uint32_t bctx_id;
-    int rc;
-    struct ibv_recv_wr wr = {}, *bad_wr;
-
-    if (!qp->ibqp) { /* This field does not get initialized for QP0 and QP1 */
-        if (qp_type == IBV_QPT_SMI) {
-            rdma_error_report("Got QP0 request");
-            complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_QP0, ctx);
-        }
-        if (qp_type == IBV_QPT_GSI) {
-            rc = save_mad_recv_buffer(backend_dev, sge, num_sge, ctx);
-            if (rc) {
-                complete_work(IBV_WC_GENERAL_ERR, rc, ctx);
-                backend_dev->rdma_dev_res->stats.mad_rx_bufs_err++;
-            } else {
-                backend_dev->rdma_dev_res->stats.mad_rx_bufs++;
-            }
-        }
-        return;
-    }
-
-    bctx = g_malloc0(sizeof(*bctx));
-    bctx->up_ctx = ctx;
-    bctx->backend_qp = qp;
-
-    rc = rdma_rm_alloc_cqe_ctx(backend_dev->rdma_dev_res, &bctx_id, bctx);
-    if (unlikely(rc)) {
-        complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_NOMEM, ctx);
-        goto err_free_bctx;
-    }
-
-    rdma_protected_gslist_append_int32(&qp->cqe_ctx_list, bctx_id);
-
-    rc = build_host_sge_array(backend_dev->rdma_dev_res, sge, num_sge,
-                              &backend_dev->rdma_dev_res->stats.rx_bufs_len);
-    if (rc) {
-        complete_work(IBV_WC_GENERAL_ERR, rc, ctx);
-        goto err_dealloc_cqe_ctx;
-    }
-
-    wr.num_sge = num_sge;
-    wr.sg_list = sge;
-    wr.wr_id = bctx_id;
-    rc = ibv_post_recv(qp->ibqp, &wr, &bad_wr);
-    if (rc) {
-        rdma_error_report("ibv_post_recv fail, qpn=0x%x, rc=%d, errno=%d",
-                          qp->ibqp->qp_num, rc, errno);
-        complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_FAIL_BACKEND, ctx);
-        goto err_dealloc_cqe_ctx;
-    }
-
-    qatomic_inc(&backend_dev->rdma_dev_res->stats.missing_cqe);
-    backend_dev->rdma_dev_res->stats.rx_bufs++;
-
-    return;
-
-err_dealloc_cqe_ctx:
-    backend_dev->rdma_dev_res->stats.rx_bufs_err++;
-    rdma_rm_dealloc_cqe_ctx(backend_dev->rdma_dev_res, bctx_id);
-
-err_free_bctx:
-    g_free(bctx);
-}
-
-void rdma_backend_post_srq_recv(RdmaBackendDev *backend_dev,
-                                RdmaBackendSRQ *srq, struct ibv_sge *sge,
-                                uint32_t num_sge, void *ctx)
-{
-    BackendCtx *bctx;
-    uint32_t bctx_id;
-    int rc;
-    struct ibv_recv_wr wr = {}, *bad_wr;
-
-    bctx = g_malloc0(sizeof(*bctx));
-    bctx->up_ctx = ctx;
-    bctx->backend_srq = srq;
-
-    rc = rdma_rm_alloc_cqe_ctx(backend_dev->rdma_dev_res, &bctx_id, bctx);
-    if (unlikely(rc)) {
-        complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_NOMEM, ctx);
-        goto err_free_bctx;
-    }
-
-    rdma_protected_gslist_append_int32(&srq->cqe_ctx_list, bctx_id);
-
-    rc = build_host_sge_array(backend_dev->rdma_dev_res, sge, num_sge,
-                              &backend_dev->rdma_dev_res->stats.rx_bufs_len);
-    if (rc) {
-        complete_work(IBV_WC_GENERAL_ERR, rc, ctx);
-        goto err_dealloc_cqe_ctx;
-    }
-
-    wr.num_sge = num_sge;
-    wr.sg_list = sge;
-    wr.wr_id = bctx_id;
-    rc = ibv_post_srq_recv(srq->ibsrq, &wr, &bad_wr);
-    if (rc) {
-        rdma_error_report("ibv_post_srq_recv fail, srqn=0x%x, rc=%d, errno=%d",
-                          srq->ibsrq->handle, rc, errno);
-        complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_FAIL_BACKEND, ctx);
-        goto err_dealloc_cqe_ctx;
-    }
-
-    qatomic_inc(&backend_dev->rdma_dev_res->stats.missing_cqe);
-    backend_dev->rdma_dev_res->stats.rx_bufs++;
-    backend_dev->rdma_dev_res->stats.rx_srq++;
-
-    return;
-
-err_dealloc_cqe_ctx:
-    backend_dev->rdma_dev_res->stats.rx_bufs_err++;
-    rdma_rm_dealloc_cqe_ctx(backend_dev->rdma_dev_res, bctx_id);
-
-err_free_bctx:
-    g_free(bctx);
-}
-
-int rdma_backend_create_pd(RdmaBackendDev *backend_dev, RdmaBackendPD *pd)
-{
-    pd->ibpd = ibv_alloc_pd(backend_dev->context);
-
-    if (!pd->ibpd) {
-        rdma_error_report("ibv_alloc_pd fail, errno=%d", errno);
-        return -EIO;
-    }
-
-    return 0;
-}
-
-void rdma_backend_destroy_pd(RdmaBackendPD *pd)
-{
-    if (pd->ibpd) {
-        ibv_dealloc_pd(pd->ibpd);
-    }
-}
-
-int rdma_backend_create_mr(RdmaBackendMR *mr, RdmaBackendPD *pd, void *addr,
-                           size_t length, uint64_t guest_start, int access)
-{
-#ifdef LEGACY_RDMA_REG_MR
-    mr->ibmr = ibv_reg_mr(pd->ibpd, addr, length, access);
-#else
-    mr->ibmr = ibv_reg_mr_iova(pd->ibpd, addr, length, guest_start, access);
-#endif
-    if (!mr->ibmr) {
-        rdma_error_report("ibv_reg_mr fail, errno=%d", errno);
-        return -EIO;
-    }
-
-    mr->ibpd = pd->ibpd;
-
-    return 0;
-}
-
-void rdma_backend_destroy_mr(RdmaBackendMR *mr)
-{
-    if (mr->ibmr) {
-        ibv_dereg_mr(mr->ibmr);
-    }
-}
-
-int rdma_backend_create_cq(RdmaBackendDev *backend_dev, RdmaBackendCQ *cq,
-                           int cqe)
-{
-    int rc;
-
-    cq->ibcq = ibv_create_cq(backend_dev->context, cqe + 1, NULL,
-                             backend_dev->channel, 0);
-    if (!cq->ibcq) {
-        rdma_error_report("ibv_create_cq fail, errno=%d", errno);
-        return -EIO;
-    }
-
-    rc = ibv_req_notify_cq(cq->ibcq, 0);
-    if (rc) {
-        rdma_warn_report("ibv_req_notify_cq fail, rc=%d, errno=%d", rc, errno);
-    }
-
-    cq->backend_dev = backend_dev;
-
-    return 0;
-}
-
-void rdma_backend_destroy_cq(RdmaBackendCQ *cq)
-{
-    if (cq->ibcq) {
-        ibv_destroy_cq(cq->ibcq);
-    }
-}
-
-int rdma_backend_create_qp(RdmaBackendQP *qp, uint8_t qp_type,
-                           RdmaBackendPD *pd, RdmaBackendCQ *scq,
-                           RdmaBackendCQ *rcq, RdmaBackendSRQ *srq,
-                           uint32_t max_send_wr, uint32_t max_recv_wr,
-                           uint32_t max_send_sge, uint32_t max_recv_sge)
-{
-    struct ibv_qp_init_attr attr = {};
-
-    qp->ibqp = 0;
-
-    switch (qp_type) {
-    case IBV_QPT_GSI:
-        return 0;
-
-    case IBV_QPT_RC:
-        /* fall through */
-    case IBV_QPT_UD:
-        /* do nothing */
-        break;
-
-    default:
-        rdma_error_report("Unsupported QP type %d", qp_type);
-        return -EIO;
-    }
-
-    attr.qp_type = qp_type;
-    attr.send_cq = scq->ibcq;
-    attr.recv_cq = rcq->ibcq;
-    attr.cap.max_send_wr = max_send_wr;
-    attr.cap.max_recv_wr = max_recv_wr;
-    attr.cap.max_send_sge = max_send_sge;
-    attr.cap.max_recv_sge = max_recv_sge;
-    if (srq) {
-        attr.srq = srq->ibsrq;
-    }
-
-    qp->ibqp = ibv_create_qp(pd->ibpd, &attr);
-    if (!qp->ibqp) {
-        rdma_error_report("ibv_create_qp fail, errno=%d", errno);
-        return -EIO;
-    }
-
-    rdma_protected_gslist_init(&qp->cqe_ctx_list);
-
-    qp->ibpd = pd->ibpd;
-
-    /* TODO: Query QP to get max_inline_data and save it to be used in send */
-
-    return 0;
-}
-
-int rdma_backend_qp_state_init(RdmaBackendDev *backend_dev, RdmaBackendQP *qp,
-                               uint8_t qp_type, uint32_t qkey)
-{
-    struct ibv_qp_attr attr = {};
-    int rc, attr_mask;
-
-    attr_mask = IBV_QP_STATE | IBV_QP_PKEY_INDEX | IBV_QP_PORT;
-    attr.qp_state        = IBV_QPS_INIT;
-    attr.pkey_index      = 0;
-    attr.port_num        = backend_dev->port_num;
-
-    switch (qp_type) {
-    case IBV_QPT_RC:
-        attr_mask |= IBV_QP_ACCESS_FLAGS;
-        trace_rdma_backend_rc_qp_state_init(qp->ibqp->qp_num);
-        break;
-
-    case IBV_QPT_UD:
-        attr.qkey = qkey;
-        attr_mask |= IBV_QP_QKEY;
-        trace_rdma_backend_ud_qp_state_init(qp->ibqp->qp_num, qkey);
-        break;
-
-    default:
-        rdma_error_report("Unsupported QP type %d", qp_type);
-        return -EIO;
-    }
-
-    rc = ibv_modify_qp(qp->ibqp, &attr, attr_mask);
-    if (rc) {
-        rdma_error_report("ibv_modify_qp fail, rc=%d, errno=%d", rc, errno);
-        return -EIO;
-    }
-
-    return 0;
-}
-
-int rdma_backend_qp_state_rtr(RdmaBackendDev *backend_dev, RdmaBackendQP *qp,
-                              uint8_t qp_type, uint8_t sgid_idx,
-                              union ibv_gid *dgid, uint32_t dqpn,
-                              uint32_t rq_psn, uint32_t qkey, bool use_qkey)
-{
-    struct ibv_qp_attr attr = {};
-    union ibv_gid ibv_gid = {
-        .global.interface_id = dgid->global.interface_id,
-        .global.subnet_prefix = dgid->global.subnet_prefix
-    };
-    int rc, attr_mask;
-
-    attr.qp_state = IBV_QPS_RTR;
-    attr_mask = IBV_QP_STATE;
-
-    qp->sgid_idx = sgid_idx;
-
-    switch (qp_type) {
-    case IBV_QPT_RC:
-        attr.path_mtu               = IBV_MTU_1024;
-        attr.dest_qp_num            = dqpn;
-        attr.max_dest_rd_atomic     = 1;
-        attr.min_rnr_timer          = 12;
-        attr.ah_attr.port_num       = backend_dev->port_num;
-        attr.ah_attr.is_global      = 1;
-        attr.ah_attr.grh.hop_limit  = 1;
-        attr.ah_attr.grh.dgid       = ibv_gid;
-        attr.ah_attr.grh.sgid_index = qp->sgid_idx;
-        attr.rq_psn                 = rq_psn;
-
-        attr_mask |= IBV_QP_AV | IBV_QP_PATH_MTU | IBV_QP_DEST_QPN |
-                     IBV_QP_RQ_PSN | IBV_QP_MAX_DEST_RD_ATOMIC |
-                     IBV_QP_MIN_RNR_TIMER;
-
-        trace_rdma_backend_rc_qp_state_rtr(qp->ibqp->qp_num,
-                                           be64_to_cpu(ibv_gid.global.
-                                                       subnet_prefix),
-                                           be64_to_cpu(ibv_gid.global.
-                                                       interface_id),
-                                           qp->sgid_idx, dqpn, rq_psn);
-        break;
-
-    case IBV_QPT_UD:
-        if (use_qkey) {
-            attr.qkey = qkey;
-            attr_mask |= IBV_QP_QKEY;
-        }
-        trace_rdma_backend_ud_qp_state_rtr(qp->ibqp->qp_num, use_qkey ? qkey :
-                                           0);
-        break;
-    }
-
-    rc = ibv_modify_qp(qp->ibqp, &attr, attr_mask);
-    if (rc) {
-        rdma_error_report("ibv_modify_qp fail, rc=%d, errno=%d", rc, errno);
-        return -EIO;
-    }
-
-    return 0;
-}
-
-int rdma_backend_qp_state_rts(RdmaBackendQP *qp, uint8_t qp_type,
-                              uint32_t sq_psn, uint32_t qkey, bool use_qkey)
-{
-    struct ibv_qp_attr attr = {};
-    int rc, attr_mask;
-
-    attr.qp_state = IBV_QPS_RTS;
-    attr.sq_psn = sq_psn;
-    attr_mask = IBV_QP_STATE | IBV_QP_SQ_PSN;
-
-    switch (qp_type) {
-    case IBV_QPT_RC:
-        attr.timeout       = 14;
-        attr.retry_cnt     = 7;
-        attr.rnr_retry     = 7;
-        attr.max_rd_atomic = 1;
-
-        attr_mask |= IBV_QP_TIMEOUT | IBV_QP_RETRY_CNT | IBV_QP_RNR_RETRY |
-                     IBV_QP_MAX_QP_RD_ATOMIC;
-        trace_rdma_backend_rc_qp_state_rts(qp->ibqp->qp_num, sq_psn);
-        break;
-
-    case IBV_QPT_UD:
-        if (use_qkey) {
-            attr.qkey = qkey;
-            attr_mask |= IBV_QP_QKEY;
-        }
-        trace_rdma_backend_ud_qp_state_rts(qp->ibqp->qp_num, sq_psn,
-                                           use_qkey ? qkey : 0);
-        break;
-    }
-
-    rc = ibv_modify_qp(qp->ibqp, &attr, attr_mask);
-    if (rc) {
-        rdma_error_report("ibv_modify_qp fail, rc=%d, errno=%d", rc, errno);
-        return -EIO;
-    }
-
-    return 0;
-}
-
-int rdma_backend_query_qp(RdmaBackendQP *qp, struct ibv_qp_attr *attr,
-                          int attr_mask, struct ibv_qp_init_attr *init_attr)
-{
-    if (!qp->ibqp) {
-        attr->qp_state = IBV_QPS_RTS;
-        return 0;
-    }
-
-    return ibv_query_qp(qp->ibqp, attr, attr_mask, init_attr);
-}
-
-void rdma_backend_destroy_qp(RdmaBackendQP *qp, RdmaDeviceResources *dev_res)
-{
-    if (qp->ibqp) {
-        ibv_destroy_qp(qp->ibqp);
-    }
-    g_slist_foreach(qp->cqe_ctx_list.list, free_cqe_ctx, dev_res);
-    rdma_protected_gslist_destroy(&qp->cqe_ctx_list);
-}
-
-int rdma_backend_create_srq(RdmaBackendSRQ *srq, RdmaBackendPD *pd,
-                            uint32_t max_wr, uint32_t max_sge,
-                            uint32_t srq_limit)
-{
-    struct ibv_srq_init_attr srq_init_attr = {};
-
-    srq_init_attr.attr.max_wr = max_wr;
-    srq_init_attr.attr.max_sge = max_sge;
-    srq_init_attr.attr.srq_limit = srq_limit;
-
-    srq->ibsrq = ibv_create_srq(pd->ibpd, &srq_init_attr);
-    if (!srq->ibsrq) {
-        rdma_error_report("ibv_create_srq failed, errno=%d", errno);
-        return -EIO;
-    }
-
-    rdma_protected_gslist_init(&srq->cqe_ctx_list);
-
-    return 0;
-}
-
-int rdma_backend_query_srq(RdmaBackendSRQ *srq, struct ibv_srq_attr *srq_attr)
-{
-    if (!srq->ibsrq) {
-        return -EINVAL;
-    }
-
-    return ibv_query_srq(srq->ibsrq, srq_attr);
-}
-
-int rdma_backend_modify_srq(RdmaBackendSRQ *srq, struct ibv_srq_attr *srq_attr,
-                int srq_attr_mask)
-{
-    if (!srq->ibsrq) {
-        return -EINVAL;
-    }
-
-    return ibv_modify_srq(srq->ibsrq, srq_attr, srq_attr_mask);
-}
-
-void rdma_backend_destroy_srq(RdmaBackendSRQ *srq, RdmaDeviceResources *dev_res)
-{
-    if (srq->ibsrq) {
-        ibv_destroy_srq(srq->ibsrq);
-    }
-    g_slist_foreach(srq->cqe_ctx_list.list, free_cqe_ctx, dev_res);
-    rdma_protected_gslist_destroy(&srq->cqe_ctx_list);
-}
-
-#define CHK_ATTR(req, dev, member, fmt) ({ \
-    trace_rdma_check_dev_attr(#member, dev.member, req->member); \
-    if (req->member > dev.member) { \
-        rdma_warn_report("%s = "fmt" is higher than host device capability "fmt, \
-                         #member, req->member, dev.member); \
-        req->member = dev.member; \
-    } \
-})
-
-static int init_device_caps(RdmaBackendDev *backend_dev,
-                            struct ibv_device_attr *dev_attr)
-{
-    struct ibv_device_attr bk_dev_attr;
-    int rc;
-
-    rc = ibv_query_device(backend_dev->context, &bk_dev_attr);
-    if (rc) {
-        rdma_error_report("ibv_query_device fail, rc=%d, errno=%d", rc, errno);
-        return -EIO;
-    }
-
-    dev_attr->max_sge = MAX_SGE;
-    dev_attr->max_srq_sge = MAX_SGE;
-
-    CHK_ATTR(dev_attr, bk_dev_attr, max_mr_size, "%" PRId64);
-    CHK_ATTR(dev_attr, bk_dev_attr, max_qp, "%d");
-    CHK_ATTR(dev_attr, bk_dev_attr, max_sge, "%d");
-    CHK_ATTR(dev_attr, bk_dev_attr, max_cq, "%d");
-    CHK_ATTR(dev_attr, bk_dev_attr, max_mr, "%d");
-    CHK_ATTR(dev_attr, bk_dev_attr, max_pd, "%d");
-    CHK_ATTR(dev_attr, bk_dev_attr, max_qp_rd_atom, "%d");
-    CHK_ATTR(dev_attr, bk_dev_attr, max_qp_init_rd_atom, "%d");
-    CHK_ATTR(dev_attr, bk_dev_attr, max_ah, "%d");
-    CHK_ATTR(dev_attr, bk_dev_attr, max_srq, "%d");
-
-    return 0;
-}
-
-static inline void build_mad_hdr(struct ibv_grh *grh, union ibv_gid *sgid,
-                                 union ibv_gid *my_gid, int paylen)
-{
-    grh->paylen = htons(paylen);
-    grh->sgid = *sgid;
-    grh->dgid = *my_gid;
-}
-
-static void process_incoming_mad_req(RdmaBackendDev *backend_dev,
-                                     RdmaCmMuxMsg *msg)
-{
-    unsigned long cqe_ctx_id;
-    BackendCtx *bctx;
-    char *mad;
-
-    trace_mad_message("recv", msg->umad.mad, msg->umad_len);
-
-    cqe_ctx_id = rdma_protected_gqueue_pop_int64(&backend_dev->recv_mads_list);
-    if (cqe_ctx_id == -ENOENT) {
-        rdma_warn_report("No more free MADs buffers, waiting for a while");
-        sleep(THR_POLL_TO);
-        return;
-    }
-
-    bctx = rdma_rm_get_cqe_ctx(backend_dev->rdma_dev_res, cqe_ctx_id);
-    if (unlikely(!bctx)) {
-        rdma_error_report("No matching ctx for req %ld", cqe_ctx_id);
-        backend_dev->rdma_dev_res->stats.mad_rx_err++;
-        return;
-    }
-
-    mad = rdma_pci_dma_map(backend_dev->dev, bctx->sge.addr,
-                           bctx->sge.length);
-    if (!mad || bctx->sge.length < msg->umad_len + MAD_HDR_SIZE) {
-        backend_dev->rdma_dev_res->stats.mad_rx_err++;
-        complete_work(IBV_WC_GENERAL_ERR, VENDOR_ERR_INV_MAD_BUFF,
-                      bctx->up_ctx);
-    } else {
-        struct ibv_wc wc = {};
-        memset(mad, 0, bctx->sge.length);
-        build_mad_hdr((struct ibv_grh *)mad,
-                      (union ibv_gid *)&msg->umad.hdr.addr.gid, &msg->hdr.sgid,
-                      msg->umad_len);
-        memcpy(&mad[MAD_HDR_SIZE], msg->umad.mad, msg->umad_len);
-        rdma_pci_dma_unmap(backend_dev->dev, mad, bctx->sge.length);
-
-        wc.byte_len = msg->umad_len;
-        wc.status = IBV_WC_SUCCESS;
-        wc.wc_flags = IBV_WC_GRH;
-        backend_dev->rdma_dev_res->stats.mad_rx++;
-        comp_handler(bctx->up_ctx, &wc);
-    }
-
-    g_free(bctx);
-    rdma_rm_dealloc_cqe_ctx(backend_dev->rdma_dev_res, cqe_ctx_id);
-}
-
-static inline int rdmacm_mux_can_receive(void *opaque)
-{
-    RdmaBackendDev *backend_dev = (RdmaBackendDev *)opaque;
-
-    return rdmacm_mux_can_process_async(backend_dev);
-}
-
-static void rdmacm_mux_read(void *opaque, const uint8_t *buf, int size)
-{
-    RdmaBackendDev *backend_dev = (RdmaBackendDev *)opaque;
-    RdmaCmMuxMsg *msg = (RdmaCmMuxMsg *)buf;
-
-    trace_rdmacm_mux("read", msg->hdr.msg_type, msg->hdr.op_code);
-
-    if (msg->hdr.msg_type != RDMACM_MUX_MSG_TYPE_REQ &&
-        msg->hdr.op_code != RDMACM_MUX_OP_CODE_MAD) {
-            rdma_error_report("Error: Not a MAD request, skipping");
-            return;
-    }
-    process_incoming_mad_req(backend_dev, msg);
-}
-
-static int mad_init(RdmaBackendDev *backend_dev, CharBackend *mad_chr_be)
-{
-    int ret;
-
-    backend_dev->rdmacm_mux.chr_be = mad_chr_be;
-
-    ret = qemu_chr_fe_backend_connected(backend_dev->rdmacm_mux.chr_be);
-    if (!ret) {
-        rdma_error_report("Missing chardev for MAD multiplexer");
-        return -EIO;
-    }
-
-    rdma_protected_gqueue_init(&backend_dev->recv_mads_list);
-
-    enable_rdmacm_mux_async(backend_dev);
-
-    qemu_chr_fe_set_handlers(backend_dev->rdmacm_mux.chr_be,
-                             rdmacm_mux_can_receive, rdmacm_mux_read, NULL,
-                             NULL, backend_dev, NULL, true);
-
-    return 0;
-}
-
-static void mad_stop(RdmaBackendDev *backend_dev)
-{
-    clean_recv_mads(backend_dev);
-}
-
-static void mad_fini(RdmaBackendDev *backend_dev)
-{
-    disable_rdmacm_mux_async(backend_dev);
-    qemu_chr_fe_disconnect(backend_dev->rdmacm_mux.chr_be);
-    rdma_protected_gqueue_destroy(&backend_dev->recv_mads_list);
-}
-
-int rdma_backend_get_gid_index(RdmaBackendDev *backend_dev,
-                               union ibv_gid *gid)
-{
-    union ibv_gid sgid;
-    int ret;
-    int i = 0;
-
-    do {
-        ret = ibv_query_gid(backend_dev->context, backend_dev->port_num, i,
-                            &sgid);
-        i++;
-    } while (!ret && (memcmp(&sgid, gid, sizeof(*gid))));
-
-    trace_rdma_backend_get_gid_index(be64_to_cpu(gid->global.subnet_prefix),
-                                     be64_to_cpu(gid->global.interface_id),
-                                     i - 1);
-
-    return ret ? ret : i - 1;
-}
-
-int rdma_backend_add_gid(RdmaBackendDev *backend_dev, const char *ifname,
-                         union ibv_gid *gid)
-{
-    RdmaCmMuxMsg msg = {};
-    int ret;
-
-    trace_rdma_backend_gid_change("add", be64_to_cpu(gid->global.subnet_prefix),
-                                  be64_to_cpu(gid->global.interface_id));
-
-    msg.hdr.op_code = RDMACM_MUX_OP_CODE_REG;
-    memcpy(msg.hdr.sgid.raw, gid->raw, sizeof(msg.hdr.sgid));
-
-    ret = rdmacm_mux_send(backend_dev, &msg);
-    if (ret) {
-        rdma_error_report("Failed to register GID to rdma_umadmux (%d)", ret);
-        return -EIO;
-    }
-
-    qapi_event_send_rdma_gid_status_changed(ifname, true,
-                                            gid->global.subnet_prefix,
-                                            gid->global.interface_id);
-
-    return ret;
-}
-
-int rdma_backend_del_gid(RdmaBackendDev *backend_dev, const char *ifname,
-                         union ibv_gid *gid)
-{
-    RdmaCmMuxMsg msg = {};
-    int ret;
-
-    trace_rdma_backend_gid_change("del", be64_to_cpu(gid->global.subnet_prefix),
-                                  be64_to_cpu(gid->global.interface_id));
-
-    msg.hdr.op_code = RDMACM_MUX_OP_CODE_UNREG;
-    memcpy(msg.hdr.sgid.raw, gid->raw, sizeof(msg.hdr.sgid));
-
-    ret = rdmacm_mux_send(backend_dev, &msg);
-    if (ret) {
-        rdma_error_report("Failed to unregister GID from rdma_umadmux (%d)",
-                          ret);
-        return -EIO;
-    }
-
-    qapi_event_send_rdma_gid_status_changed(ifname, false,
-                                            gid->global.subnet_prefix,
-                                            gid->global.interface_id);
-
-    return 0;
-}
-
-int rdma_backend_init(RdmaBackendDev *backend_dev, PCIDevice *pdev,
-                      RdmaDeviceResources *rdma_dev_res,
-                      const char *backend_device_name, uint8_t port_num,
-                      struct ibv_device_attr *dev_attr, CharBackend *mad_chr_be)
-{
-    int i;
-    int ret = 0;
-    int num_ibv_devices;
-    struct ibv_device **dev_list;
-
-    memset(backend_dev, 0, sizeof(*backend_dev));
-
-    backend_dev->dev = pdev;
-    backend_dev->port_num = port_num;
-    backend_dev->rdma_dev_res = rdma_dev_res;
-
-    rdma_backend_register_comp_handler(dummy_comp_handler);
-
-    dev_list = ibv_get_device_list(&num_ibv_devices);
-    if (!dev_list) {
-        rdma_error_report("Failed to get IB devices list");
-        return -EIO;
-    }
-
-    if (num_ibv_devices == 0) {
-        rdma_error_report("No IB devices were found");
-        ret = -ENXIO;
-        goto out_free_dev_list;
-    }
-
-    if (backend_device_name) {
-        for (i = 0; dev_list[i]; ++i) {
-            if (!strcmp(ibv_get_device_name(dev_list[i]),
-                        backend_device_name)) {
-                break;
-            }
-        }
-
-        backend_dev->ib_dev = dev_list[i];
-        if (!backend_dev->ib_dev) {
-            rdma_error_report("Failed to find IB device %s",
-                              backend_device_name);
-            ret = -EIO;
-            goto out_free_dev_list;
-        }
-    } else {
-        backend_dev->ib_dev = *dev_list;
-    }
-
-    rdma_info_report("uverb device %s", backend_dev->ib_dev->dev_name);
-
-    backend_dev->context = ibv_open_device(backend_dev->ib_dev);
-    if (!backend_dev->context) {
-        rdma_error_report("Failed to open IB device %s",
-                          ibv_get_device_name(backend_dev->ib_dev));
-        ret = -EIO;
-        goto out;
-    }
-
-    backend_dev->channel = ibv_create_comp_channel(backend_dev->context);
-    if (!backend_dev->channel) {
-        rdma_error_report("Failed to create IB communication channel");
-        ret = -EIO;
-        goto out_close_device;
-    }
-
-    ret = init_device_caps(backend_dev, dev_attr);
-    if (ret) {
-        rdma_error_report("Failed to initialize device capabilities");
-        ret = -EIO;
-        goto out_destroy_comm_channel;
-    }
-
-
-    ret = mad_init(backend_dev, mad_chr_be);
-    if (ret) {
-        rdma_error_report("Failed to initialize mad");
-        ret = -EIO;
-        goto out_destroy_comm_channel;
-    }
-
-    backend_dev->comp_thread.run = false;
-    backend_dev->comp_thread.is_running = false;
-
-    ah_cache_init();
-
-    goto out_free_dev_list;
-
-out_destroy_comm_channel:
-    ibv_destroy_comp_channel(backend_dev->channel);
-
-out_close_device:
-    ibv_close_device(backend_dev->context);
-
-out_free_dev_list:
-    ibv_free_device_list(dev_list);
-
-out:
-    return ret;
-}
-
-
-void rdma_backend_start(RdmaBackendDev *backend_dev)
-{
-    start_comp_thread(backend_dev);
-}
-
-void rdma_backend_stop(RdmaBackendDev *backend_dev)
-{
-    mad_stop(backend_dev);
-    stop_backend_thread(&backend_dev->comp_thread);
-}
-
-void rdma_backend_fini(RdmaBackendDev *backend_dev)
-{
-    mad_fini(backend_dev);
-    g_hash_table_destroy(ah_hash);
-    ibv_destroy_comp_channel(backend_dev->channel);
-    ibv_close_device(backend_dev->context);
-}