I&#x27;m talking about the complexity of what the kernel-level thing is implementing. It&#x27;s pretty easy to make a secure Hello World program, even if it&#x27;s running in kernel mode. It&#x27;s arguably impossible to make a secure implementation of the linux API, which is not even formally documented. The x86 spec is not simple but at least there is a spec. Floppy driver local root is a good example - the linux kernel suffers from that, but a hypervisor might well not even implement a floppy driver.