fn vm_memory_handler_thread(
    control_tubes: Vec<VmMemoryTube>,
    vm: impl Vm,
    sys_allocator_mutex: Arc<Mutex<SystemAllocator>>,
    gralloc: RutabagaGralloc,
    iommu_client: Option<VmMemoryRequestIommuClient>,
    handler_control: Tube
) -> Result<()>