virtio_gpu_resource_attach_backing(VirtIOGPU *g,
                                   struct virtio_gpu_ctrl_command *cmd)
{
    struct virtio_gpu_simple_resource *res;
    struct virtio_gpu_resource_attach_backing ab;
    int ret;

    VIRTIO_GPU_FILL_CMD(ab);
    trace_virtio_gpu_cmd_res_back_attach(ab.resource_id);

    res = virtio_gpu_find_resource(g, ab.resource_id);
    if (!res) {
        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal resource specified %d\n",
                      __func__, ab.resource_id);
        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
        return;
    }

    if (res->iov) {
        cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
        return;
    }

    ret = virtio_gpu_create_mapping_iov(&ab, cmd, &res->addrs, &res->iov);
    if (ret != 0) {
        cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
        return;
    }

    res->iov_cnt = ab.nr_entries;
}

The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.