THROWF(vm_error, 0, "Cannot migrate VM '%s' that is not running yet.", vm->get_cname());
if (vm->get_impl()->is_migrating_)
THROWF(vm_error, 0, "Cannot migrate VM '%s' that is already migrating.", vm->get_cname());
vm->get_impl()->is_migrating_ = true;
THROWF(vm_error, 0, "Cannot migrate VM '%s' that is not running yet.", vm->get_cname());
if (vm->get_impl()->is_migrating_)
THROWF(vm_error, 0, "Cannot migrate VM '%s' that is already migrating.", vm->get_cname());
vm->get_impl()->is_migrating_ = true;