A firewall for device drivers

Unfortunately the VM itself can change the blacklists, and obtain the modules from somewhere and insmod them. When your goal is to ensure someone who has taken over the VM can't escape from it, that's not a solution.

However, a simple sysfs "blown fuse flag" (ie, one you can not change back) that turns off module loading would work. You just run set it in the initrd, after it's loaded all the modules. There already is a corresponding capability.