C++ VirtioBusClass::set_guest_notifiers方法代码示例

/* Context: QEMU global mutex held */
void virtio_scsi_dataplane_start(VirtIOSCSI *s)
{
    int i;
    int rc;
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);

    if (s->dataplane_started ||
        s->dataplane_starting ||
        s->dataplane_fenced ||
        s->ctx != iothread_get_aio_context(vs->conf.iothread)) {
        return;
    }

    s->dataplane_starting = true;

    /* Set up guest notifier (irq) */
    rc = k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, true);
    if (rc != 0) {
        fprintf(stderr, "virtio-scsi: Failed to set guest notifiers (%d), "
                "ensure -enable-kvm is set\n", rc);
        goto fail_guest_notifiers;
    }

    aio_context_acquire(s->ctx);
    rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0);
    if (rc) {
        goto fail_vrings;
    }
    rc = virtio_scsi_vring_init(s, vs->event_vq, 1);
    if (rc) {
        goto fail_vrings;
    }
    for (i = 0; i < vs->conf.num_queues; i++) {
        rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2);
        if (rc) {
            goto fail_vrings;
        }
    }

    s->dataplane_starting = false;
    s->dataplane_started = true;
    aio_context_release(s->ctx);
    return;

fail_vrings:
    virtio_scsi_clear_aio(s);
    aio_context_release(s->ctx);
    for (i = 0; i < vs->conf.num_queues + 2; i++) {
        k->set_host_notifier(qbus->parent, i, false);
    }
    k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
fail_guest_notifiers:
    s->dataplane_fenced = true;
    s->dataplane_starting = false;
    s->dataplane_started = true;
}

static void vhost_vsock_start(VirtIODevice *vdev)
{
    VHostVSock *vsock = VHOST_VSOCK(vdev);
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    int ret;
    int i;

    if (!k->set_guest_notifiers) {
        error_report("binding does not support guest notifiers");
        return;
    }

    ret = vhost_dev_enable_notifiers(&vsock->vhost_dev, vdev);
    if (ret < 0) {
        error_report("Error enabling host notifiers: %d", -ret);
        return;
    }

    ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, true);
    if (ret < 0) {
        error_report("Error binding guest notifier: %d", -ret);
        goto err_host_notifiers;
    }

    vsock->vhost_dev.acked_features = vdev->guest_features;
    ret = vhost_dev_start(&vsock->vhost_dev, vdev);
    if (ret < 0) {
        error_report("Error starting vhost: %d", -ret);
        goto err_guest_notifiers;
    }

    ret = vhost_vsock_set_running(vsock, 1);
    if (ret < 0) {
        error_report("Error starting vhost vsock: %d", -ret);
        goto err_dev_start;
    }

    /* guest_notifier_mask/pending not used yet, so just unmask
     * everything here.  virtio-pci will do the right thing by
     * enabling/disabling irqfd.
     */
    for (i = 0; i < vsock->vhost_dev.nvqs; i++) {
        vhost_virtqueue_mask(&vsock->vhost_dev, vdev, i, false);
    }

    return;

err_dev_start:
    vhost_dev_stop(&vsock->vhost_dev, vdev);
err_guest_notifiers:
    k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
err_host_notifiers:
    vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
}

/* Context: QEMU global mutex held */
void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
{
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
    int r;

    if (vblk->dataplane_started || s->starting) {
        return;
    }

    s->starting = true;
    s->vq = virtio_get_queue(s->vdev, 0);

    /* Set up guest notifier (irq) */
    r = k->set_guest_notifiers(qbus->parent, 1, true);
    if (r != 0) {
        fprintf(stderr, "virtio-blk failed to set guest notifier (%d), "
                "ensure -enable-kvm is set\n", r);
        goto fail_guest_notifiers;
    }
    s->guest_notifier = virtio_queue_get_guest_notifier(s->vq);

    /* Set up virtqueue notify */
    r = k->set_host_notifier(qbus->parent, 0, true);
    if (r != 0) {
        fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
        goto fail_host_notifier;
    }

    s->starting = false;
    vblk->dataplane_started = true;
    trace_virtio_blk_data_plane_start(s);

    blk_set_aio_context(s->conf->conf.blk, s->ctx);

    /* Kick right away to begin processing requests already in vring */
    event_notifier_set(virtio_queue_get_host_notifier(s->vq));

    /* Get this show started by hooking up our callbacks */
    aio_context_acquire(s->ctx);
    virtio_queue_aio_set_host_notifier_handler(s->vq, s->ctx,
                                               virtio_blk_data_plane_handle_output);
    aio_context_release(s->ctx);
    return;

  fail_host_notifier:
    k->set_guest_notifiers(qbus->parent, 1, false);
  fail_guest_notifiers:
    vblk->dataplane_disabled = true;
    s->starting = false;
    vblk->dataplane_started = true;
}

static void vhost_vsock_stop(VirtIODevice *vdev)
{
    VHostVSock *vsock = VHOST_VSOCK(vdev);
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    int ret;

    if (!k->set_guest_notifiers) {
        return;
    }

    ret = vhost_vsock_set_running(vsock, 0);
    if (ret < 0) {
        error_report("vhost vsock set running failed: %d", ret);
        return;
    }

    vhost_dev_stop(&vsock->vhost_dev, vdev);

    ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
    if (ret < 0) {
        error_report("vhost guest notifier cleanup failed: %d", ret);
        return;
    }

    vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
}

int vhost_scsi_common_start(VHostSCSICommon *vsc)
{
    int ret, i;
    VirtIODevice *vdev = VIRTIO_DEVICE(vsc);
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);

    if (!k->set_guest_notifiers) {
        error_report("binding does not support guest notifiers");
        return -ENOSYS;
    }

    ret = vhost_dev_enable_notifiers(&vsc->dev, vdev);
    if (ret < 0) {
        return ret;
    }

    ret = k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, true);
    if (ret < 0) {
        error_report("Error binding guest notifier");
        goto err_host_notifiers;
    }

    vsc->dev.acked_features = vdev->guest_features;
    ret = vhost_dev_start(&vsc->dev, vdev);
    if (ret < 0) {
        error_report("Error start vhost dev");
        goto err_guest_notifiers;
    }

    /* guest_notifier_mask/pending not used yet, so just unmask
     * everything here.  virtio-pci will do the right thing by
     * enabling/disabling irqfd.
     */
    for (i = 0; i < vsc->dev.nvqs; i++) {
        vhost_virtqueue_mask(&vsc->dev, vdev, vsc->dev.vq_index + i, false);
    }

    return ret;

err_guest_notifiers:
    k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, false);
err_host_notifiers:
    vhost_dev_disable_notifiers(&vsc->dev, vdev);
    return ret;
}

static void vhost_net_stop_one(struct vhost_net *net,
                               VirtIODevice *dev)
{
    struct vhost_vring_file file = { .fd = -1 };

    if (!net->dev.started) {
        return;
    }

    for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
        int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
        assert(r >= 0);
    }
    net->nc->info->poll(net->nc, true);
    vhost_dev_stop(&net->dev, dev);
    vhost_dev_disable_notifiers(&net->dev, dev);
}

int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
                    int total_queues)
{
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
    VirtioBusState *vbus = VIRTIO_BUS(qbus);
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
    int r, i = 0;

    if (!k->set_guest_notifiers) {
        error_report("binding does not support guest notifiers");
        r = -ENOSYS;
        goto err;
    }

    for (i = 0; i < total_queues; i++) {
        r = vhost_net_start_one(tap_get_vhost_net(ncs[i].peer), dev, i * 2);

        if (r < 0) {
            goto err;
        }
    }

    r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
    if (r < 0) {
        error_report("Error binding guest notifier: %d", -r);
        goto err;
    }

    return 0;

err:
    while (--i >= 0) {
        vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
    }
    return r;
}

/* Context: QEMU global mutex held */
void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
{
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
    unsigned i;
    unsigned nvqs = s->conf->num_queues;

    if (!vblk->dataplane_started || s->stopping) {
        return;
    }

    /* Better luck next time. */
    if (vblk->dataplane_disabled) {
        vblk->dataplane_disabled = false;
        vblk->dataplane_started = false;
        return;
    }
    s->stopping = true;
    trace_virtio_blk_data_plane_stop(s);

    aio_context_acquire(s->ctx);

    /* Stop notifications for new requests from guest */
    for (i = 0; i < nvqs; i++) {
        VirtQueue *vq = virtio_get_queue(s->vdev, i);

        virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, NULL);
    }

    /* Drain and switch bs back to the QEMU main loop */
    blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context());

    aio_context_release(s->ctx);

    for (i = 0; i < nvqs; i++) {
        virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
    }

    /* Clean up guest notifier (irq) */
    k->set_guest_notifiers(qbus->parent, nvqs, false);

    vblk->dataplane_started = false;
    s->stopping = false;
}

static void vhost_scsi_stop(VHostSCSI *s)
{
    VirtIODevice *vdev = VIRTIO_DEVICE(s);
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    int ret = 0;

    if (k->set_guest_notifiers) {
        ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
        if (ret < 0) {
                error_report("vhost guest notifier cleanup failed: %d\n", ret);
        }
    }
    assert(ret >= 0);

    vhost_scsi_clear_endpoint(s);
    vhost_dev_stop(&s->dev, vdev);
    vhost_dev_disable_notifiers(&s->dev, vdev);
}

void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
                    int total_queues)
{
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
    VirtioBusState *vbus = VIRTIO_BUS(qbus);
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
    int i, r;

    for (i = 0; i < total_queues; i++) {
        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
    }

    r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
    if (r < 0) {
        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
        fflush(stderr);
    }
    assert(r >= 0);
}

/* Context: QEMU global mutex held */
void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
{
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);


    /* Better luck next time. */
    if (s->disabled) {
        s->disabled = false;
        return;
    }
    if (!s->started || s->stopping) {
        return;
    }
    s->stopping = true;
    vblk->complete_request = s->saved_complete_request;
    trace_virtio_blk_data_plane_stop(s);

    aio_context_acquire(s->ctx);

    /* Stop notifications for new requests from guest */
    aio_set_event_notifier(s->ctx, &s->host_notifier, true, NULL);

    /* Drain and switch bs back to the QEMU main loop */
    blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context());

    aio_context_release(s->ctx);

    /* Sync vring state back to virtqueue so that non-dataplane request
     * processing can continue when we disable the host notifier below.
     */
    vring_teardown(&s->vring, s->vdev, 0);

    k->set_host_notifier(qbus->parent, 0, false);

    /* Clean up guest notifier (irq) */
    k->set_guest_notifiers(qbus->parent, 1, false);

    s->started = false;
    s->stopping = false;
}

/* Context: QEMU global mutex held */
void virtio_scsi_dataplane_stop(VirtIOSCSI *s)
{
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
    int i;

    if (!s->dataplane_started || s->dataplane_stopping) {
        return;
    }

    /* Better luck next time. */
    if (s->dataplane_fenced) {
        s->dataplane_fenced = false;
        s->dataplane_started = false;
        return;
    }
    s->dataplane_stopping = true;
    assert(s->ctx == iothread_get_aio_context(vs->conf.iothread));

    aio_context_acquire(s->ctx);

    virtio_scsi_clear_aio(s);

    blk_drain_all(); /* ensure there are no in-flight requests */

    aio_context_release(s->ctx);

    for (i = 0; i < vs->conf.num_queues + 2; i++) {
        k->set_host_notifier(qbus->parent, i, false);
    }

    /* Clean up guest notifier (irq) */
    k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
    s->dataplane_stopping = false;
    s->dataplane_started = false;
}

static int vhost_scsi_start(VHostSCSI *s)
{
    int ret, abi_version, i;
    VirtIODevice *vdev = VIRTIO_DEVICE(s);
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);

    if (!k->set_guest_notifiers) {
        error_report("binding does not support guest notifiers");
        return -ENOSYS;
    }

    ret = ioctl(s->dev.control, VHOST_SCSI_GET_ABI_VERSION, &abi_version);
    if (ret < 0) {
        return -errno;
    }
    if (abi_version > VHOST_SCSI_ABI_VERSION) {
        error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
                     " %d is greater than vhost_scsi userspace supports: %d, please"
                     " upgrade your version of QEMU\n", abi_version,
                     VHOST_SCSI_ABI_VERSION);
        return -ENOSYS;
    }

    ret = vhost_dev_enable_notifiers(&s->dev, vdev);
    if (ret < 0) {
        return ret;
    }

    s->dev.acked_features = vdev->guest_features;
    ret = vhost_dev_start(&s->dev, vdev);
    if (ret < 0) {
        error_report("Error start vhost dev");
        goto err_notifiers;
    }

    ret = vhost_scsi_set_endpoint(s);
    if (ret < 0) {
        error_report("Error set vhost-scsi endpoint");
        goto err_vhost_stop;
    }

    ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
    if (ret < 0) {
        error_report("Error binding guest notifier");
        goto err_endpoint;
    }

    /* guest_notifier_mask/pending not used yet, so just unmask
     * everything here.  virtio-pci will do the right thing by
     * enabling/disabling irqfd.
     */
    for (i = 0; i < s->dev.nvqs; i++) {
        vhost_virtqueue_mask(&s->dev, vdev, i, false);
    }

    return ret;

err_endpoint:
    vhost_scsi_clear_endpoint(s);
err_vhost_stop:
    vhost_dev_stop(&s->dev, vdev);
err_notifiers:
    vhost_dev_disable_notifiers(&s->dev, vdev);
    return ret;
}

static void vhost_net_stop_one(struct vhost_net *net,
                               VirtIODevice *dev)
{
    struct vhost_vring_file file = { .fd = -1 };

    if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
        for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
            const VhostOps *vhost_ops = net->dev.vhost_ops;
            int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
                                          &file);
            assert(r >= 0);
        }
    }
    if (net->nc->info->poll) {
        net->nc->info->poll(net->nc, true);
    }
    vhost_dev_stop(&net->dev, dev);
    vhost_dev_disable_notifiers(&net->dev, dev);
}

static bool vhost_net_device_endian_ok(VirtIODevice *vdev)
{
#ifdef TARGET_IS_BIENDIAN
#ifdef HOST_WORDS_BIGENDIAN
    return virtio_is_big_endian(vdev);
#else
    return !virtio_is_big_endian(vdev);
#endif
#else
    return true;
#endif
}

int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
                    int total_queues)
{
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
    VirtioBusState *vbus = VIRTIO_BUS(qbus);
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
    int r, e, i;

    if (!vhost_net_device_endian_ok(dev)) {
        error_report("vhost-net does not support cross-endian");
        r = -ENOSYS;
        goto err;
    }

    if (!k->set_guest_notifiers) {
        error_report("binding does not support guest notifiers");
        r = -ENOSYS;
        goto err;
    }

    for (i = 0; i < total_queues; i++) {
        vhost_net_set_vq_index(get_vhost_net(ncs[i].peer), i * 2);
    }

    r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
    if (r < 0) {
        error_report("Error binding guest notifier: %d", -r);
        goto err;
    }

    for (i = 0; i < total_queues; i++) {
        r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);

        if (r < 0) {
            goto err_start;
        }
    }

    return 0;

err_start:
    while (--i >= 0) {
        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
    }
    e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
    if (e < 0) {
        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
        fflush(stderr);
    }
err:
    return r;
}

static void vhost_net_stop_one(struct vhost_net *net,
                               VirtIODevice *dev)
{
    struct vhost_vring_file file = { .fd = -1 };

    if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
        for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
            const VhostOps *vhost_ops = net->dev.vhost_ops;
            int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
                                          &file);
            assert(r >= 0);
        }
    }
    if (net->nc->info->poll) {
        net->nc->info->poll(net->nc, true);
    }
    vhost_dev_stop(&net->dev, dev);
    vhost_dev_disable_notifiers(&net->dev, dev);
}

int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
                    int total_queues)
{
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
    VirtioBusState *vbus = VIRTIO_BUS(qbus);
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
    int r, e, i;

    if (!k->set_guest_notifiers) {
        error_report("binding does not support guest notifiers");
        r = -ENOSYS;
        goto err;
    }

    r = vhost_net_set_vnet_endian(dev, ncs[0].peer, true);
    if (r < 0) {
        goto err;
    }

    for (i = 0; i < total_queues; i++) {
        struct vhost_net *net;

        net = get_vhost_net(ncs[i].peer);
        vhost_net_set_vq_index(net, i * 2);

        /* Suppress the masking guest notifiers on vhost user
         * because vhost user doesn't interrupt masking/unmasking
         * properly.
         */
        if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
                dev->use_guest_notifier_mask = false;
        }
     }

    r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
    if (r < 0) {
        error_report("Error binding guest notifier: %d", -r);
        goto err_endian;
    }

    for (i = 0; i < total_queues; i++) {
        r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);

        if (r < 0) {
            goto err_start;
        }

        if (ncs[i].peer->vring_enable) {
            /* restore vring enable state */
            r = vhost_set_vring_enable(ncs[i].peer, ncs[i].peer->vring_enable);

            if (r < 0) {
                goto err_start;
            }
        }
    }

    return 0;

err_start:
    while (--i >= 0) {
        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
    }
    e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
    if (e < 0) {
        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
        fflush(stderr);
    }
err_endian:
    vhost_net_set_vnet_endian(dev, ncs[0].peer, false);
err:
    return r;
}

static void vhost_net_stop_one(struct vhost_net *net,
                               VirtIODevice *dev)
{
    struct vhost_vring_file file = { .fd = -1 };

    if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
        for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
            const VhostOps *vhost_ops = net->dev.vhost_ops;
            int r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
            assert(r >= 0);
        }
    }
    if (net->nc->info->poll) {
        net->nc->info->poll(net->nc, true);
    }
    vhost_dev_stop(&net->dev, dev);
    vhost_dev_disable_notifiers(&net->dev, dev);
}

int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
                    int total_queues)
{
    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
    VirtioBusState *vbus = VIRTIO_BUS(qbus);
    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
    int r, e, i, j;

    if (!k->set_guest_notifiers) {
        error_report("binding does not support guest notifiers");
        return -ENOSYS;
    }

    for (j = 0; j < total_queues; j++) {
        r = vhost_net_set_vnet_endian(dev, ncs[j].peer, true);
        if (r < 0) {
            goto err_endian;
        }
        vhost_net_set_vq_index(get_vhost_net(ncs[j].peer), j * 2);
    }

    r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
    if (r < 0) {
        error_report("Error binding guest notifier: %d", -r);
        goto err_endian;
    }

    for (i = 0; i < total_queues; i++) {
        r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);

        if (r < 0) {
            goto err_start;
        }
    }

    return 0;

err_start:
    while (--i >= 0) {
        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
    }
    e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
    if (e < 0) {
        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
        fflush(stderr);
    }
err_endian:
    while (--j >= 0) {
        vhost_net_set_vnet_endian(dev, ncs[j].peer, false);
    }
    return r;
}