C++ VIRTIO_DEVICE函数代码示例

static bool virtio_balloon_free_page_support(void *opaque)
{
    VirtIOBalloon *s = opaque;
    VirtIODevice *vdev = VIRTIO_DEVICE(s);

    return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT);
}

static void virtio_serial_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
{
    VirtIOSerialPCI *dev = VIRTIO_SERIAL_PCI(vpci_dev);
    DeviceState *vdev = DEVICE(&dev->vdev);
    DeviceState *proxy = DEVICE(vpci_dev);
    char *bus_name;

    if (vpci_dev->class_code != PCI_CLASS_COMMUNICATION_OTHER &&
        vpci_dev->class_code != PCI_CLASS_DISPLAY_OTHER && /* qemu 0.10 */
        vpci_dev->class_code != PCI_CLASS_OTHERS) {        /* qemu-kvm  */
            vpci_dev->class_code = PCI_CLASS_COMMUNICATION_OTHER;
    }

    /* backwards-compatibility with machines that were created with
       DEV_NVECTORS_UNSPECIFIED */
    if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
        vpci_dev->nvectors = dev->vdev.serial.max_virtserial_ports + 1;
    }

    /*
     * For command line compatibility, this sets the virtio-serial-device bus
     * name as before.
     */
    if (proxy->id) {
        bus_name = g_strdup_printf("%s.0", proxy->id);
        virtio_device_set_child_bus_name(VIRTIO_DEVICE(vdev), bus_name);
        g_free(bus_name);
    }

    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
    object_property_set_bool(OBJECT(vdev), true, "realized", errp);
}

static void virtio_blk_handle_write(VirtIOBlockReq *req, MultiReqBuffer *mrb)
{
    BlockRequest *blkreq;
    uint64_t sector;

    sector = virtio_ldq_p(VIRTIO_DEVICE(req->dev), &req->out.sector);

    bdrv_acct_start(req->dev->bs, &req->acct, req->qiov.size, BDRV_ACCT_WRITE);

    trace_virtio_blk_handle_write(req, sector, req->qiov.size / 512);

    if (sector & req->dev->sector_mask) {
        virtio_blk_rw_complete(req, -EIO);
        return;
    }
    if (req->qiov.size % req->dev->conf->logical_block_size) {
        virtio_blk_rw_complete(req, -EIO);
        return;
    }

    if (mrb->num_writes == 32) {
        virtio_submit_multiwrite(req->dev->bs, mrb);
    }

    blkreq = &mrb->blkreq[mrb->num_writes];
    blkreq->sector = sector;
    blkreq->nb_sectors = req->qiov.size / BDRV_SECTOR_SIZE;
    blkreq->qiov = &req->qiov;
    blkreq->cb = virtio_blk_rw_complete;
    blkreq->opaque = req;
    blkreq->error = 0;

    mrb->num_writes++;
}

static void virtio_blk_rw_complete(void *opaque, int ret)
{
    VirtIOBlockReq *next = opaque;

    while (next) {
        VirtIOBlockReq *req = next;
        next = req->mr_next;
        trace_virtio_blk_rw_complete(req, ret);

        if (req->qiov.nalloc != -1) {
            /* If nalloc is != 1 req->qiov is a local copy of the original
             * external iovec. It was allocated in submit_merged_requests
             * to be able to merge requests. */
            qemu_iovec_destroy(&req->qiov);
        }

        if (ret) {
            int p = virtio_ldl_p(VIRTIO_DEVICE(req->dev), &req->out.type);
            bool is_read = !(p & VIRTIO_BLK_T_OUT);
            if (virtio_blk_handle_rw_error(req, -ret, is_read)) {
                continue;
            }
        }

        virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
        block_acct_done(blk_get_stats(req->dev->blk), &req->acct);
        virtio_blk_free_request(req);
    }
}

static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id)
{
    VirtIOBlock *s = opaque;
    VirtIODevice *vdev = VIRTIO_DEVICE(s);
    int ret;

    if (version_id != 2)
        return -EINVAL;

    ret = virtio_load(vdev, f);
    if (ret) {
        return ret;
    }

    while (qemu_get_sbyte(f)) {
        VirtIOBlockReq *req = virtio_blk_alloc_request(s);
        qemu_get_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
        req->next = s->rq;
        s->rq = req;

        virtqueue_map_sg(req->elem.in_sg, req->elem.in_addr,
            req->elem.in_num, 1);
        virtqueue_map_sg(req->elem.out_sg, req->elem.out_addr,
            req->elem.out_num, 0);
    }

    return 0;
}

static void virtio_crypto_dataq_bh(void *opaque)
{
    VirtIOCryptoQueue *q = opaque;
    VirtIOCrypto *vcrypto = q->vcrypto;
    VirtIODevice *vdev = VIRTIO_DEVICE(vcrypto);

    /* This happens when device was stopped but BH wasn't. */
    if (!vdev->vm_running) {
        return;
    }

    /* Just in case the driver is not ready on more */
    if (unlikely(!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))) {
        return;
    }

    for (;;) {
        virtio_crypto_handle_dataq(vdev, q->dataq);
        virtio_queue_set_notification(q->dataq, 1);

        /* Are we done or did the guest add more buffers? */
        if (virtio_queue_empty(q->dataq)) {
            break;
        }

        virtio_queue_set_notification(q->dataq, 0);
    }
}

static int vhost_vsock_load(QEMUFile *f, void *opaque, size_t size)
{
    VHostVSock *vsock = opaque;
    VirtIODevice *vdev = VIRTIO_DEVICE(vsock);
    int ret;

    ret = virtio_load(vdev, f, VHOST_VSOCK_SAVEVM_VERSION);
    if (ret) {
        return ret;
    }

    if (virtio_queue_get_addr(vdev, 2)) {
        /* Defer transport reset event to a vm clock timer so that virtqueue
         * changes happen after migration has completed.
         */
        assert(!vsock->post_load_timer);
        vsock->post_load_timer =
            timer_new_ns(QEMU_CLOCK_VIRTUAL,
                         vhost_vsock_post_load_timer_cb,
                         vsock);
        timer_mod(vsock->post_load_timer, 1);
    }

    return 0;
}

static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id)
{
    if (version_id != 1)
        return -EINVAL;

    return virtio_load(VIRTIO_DEVICE(opaque), f, version_id);
}

static void vhost_vsock_send_transport_reset(VHostVSock *vsock)
{
    VirtQueueElement *elem;
    VirtQueue *vq = vsock->event_vq;
    struct virtio_vsock_event event = {
        .id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET),
    };

    elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
    if (!elem) {
        error_report("vhost-vsock missed transport reset event");
        return;
    }

    if (elem->out_num) {
        error_report("invalid vhost-vsock event virtqueue element with "
                     "out buffers");
        goto out;
    }

    if (iov_from_buf(elem->in_sg, elem->in_num, 0,
                     &event, sizeof(event)) != sizeof(event)) {
        error_report("vhost-vsock event virtqueue element is too short");
        goto out;
    }

    virtqueue_push(vq, elem, sizeof(event));
    virtio_notify(VIRTIO_DEVICE(vsock), vq);

out:
    g_free(elem);
}

/* Disable dataplane thread during live migration since it does not
 * update the dirty memory bitmap yet.
 */
static void virtio_blk_migration_state_changed(Notifier *notifier, void *data)
{
    VirtIOBlock *s = container_of(notifier, VirtIOBlock,
                                  migration_state_notifier);
    MigrationState *mig = data;
    Error *err = NULL;

    if (migration_in_setup(mig)) {
        if (!s->dataplane) {
            return;
        }
        virtio_blk_data_plane_destroy(s->dataplane);
        s->dataplane = NULL;
    } else if (migration_has_finished(mig) ||
               migration_has_failed(mig)) {
        if (s->dataplane) {
            return;
        }
        bdrv_drain_all(); /* complete in-flight non-dataplane requests */
        virtio_blk_data_plane_create(VIRTIO_DEVICE(s), &s->blk,
                                     &s->dataplane, &err);
        if (err != NULL) {
            error_report("%s", error_get_pretty(err));
            error_free(err);
        }
    }
}

static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
{
    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
    VirtIOBalloon *s = VIRTIO_BALLOON(dev);
    int ret;

    virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON,
                sizeof(struct virtio_balloon_config));

    ret = qemu_add_balloon_handler(virtio_balloon_to_target,
                                   virtio_balloon_stat, s);

    if (ret < 0) {
        error_setg(errp, "Only one balloon device is supported");
        virtio_cleanup(vdev);
        return;
    }

    s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
    s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
    s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);

    reset_stats(s);

    register_savevm(dev, "virtio-balloon", -1, 1,
                    virtio_balloon_save, virtio_balloon_load, s);
}

static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
{
    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
    VirtIOBalloon *s = VIRTIO_BALLOON(dev);
    int ret;

    virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON,
                sizeof(struct virtio_balloon_config));

    ret = qemu_add_balloon_handler(virtio_balloon_to_target,
                                   virtio_balloon_stat, s);

    if (ret < 0) {
        error_setg(errp, "Adding balloon handler failed");
        virtio_cleanup(vdev);
        return;
    }

    s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
    s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
    s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);

    register_savevm(dev, "virtio-balloon", -1, 1,
                    virtio_balloon_save, virtio_balloon_load, s);

    object_property_add(OBJECT(dev), "guest-stats", "guest statistics",
                        balloon_stats_get_all, NULL, NULL, s, NULL);

    object_property_add(OBJECT(dev), "guest-stats-polling-interval", "int",
                        balloon_stats_get_poll_interval,
                        balloon_stats_set_poll_interval,
                        NULL, s, NULL);
}

static void virtio_cuda_realize(DeviceState *dev, Error **errp)
{
	VirtIODevice *vdev = VIRTIO_DEVICE(dev);

	virtio_init(vdev, "virtio-cuda", 13, 0);
	virtio_add_queue(vdev, 1024, vq_handle_output);
}

static int virtio_balloon_device_init(VirtIODevice *vdev)
{
    DeviceState *qdev = DEVICE(vdev);
    VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
    int ret;

    virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON, 8);

    ret = qemu_add_balloon_handler(virtio_balloon_to_target,
                                   virtio_balloon_stat, s);

    if (ret < 0) {
        virtio_cleanup(VIRTIO_DEVICE(s));
        return -1;
    }

    s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
    s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
    s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);

    register_savevm(qdev, "virtio-balloon", -1, 1,
                    virtio_balloon_save, virtio_balloon_load, s);

    object_property_add(OBJECT(qdev), "guest-stats", "guest statistics",
                        balloon_stats_get_all, NULL, NULL, s, NULL);

    object_property_add(OBJECT(qdev), "guest-stats-polling-interval", "int",
                        balloon_stats_get_poll_interval,
                        balloon_stats_set_poll_interval,
                        NULL, s, NULL);
    return 0;
}

static void virtio_balloon_free_page_done(VirtIOBalloon *s)
{
    VirtIODevice *vdev = VIRTIO_DEVICE(s);

    s->free_page_report_status = FREE_PAGE_REPORT_S_DONE;
    virtio_notify_config(vdev);
}