IOPF_DRV_HOOK
err = vm_inout_attach(&vm->ioports, port, IOPF_DRV_HOOK, func, arg);
if (drv_hook && (compare->iope_flags & IOPF_DRV_HOOK) == 0) {
(compare->iope_flags & IOPF_DRV_HOOK) != 0) {