alt Hacker NewsThat is a artifact of implementation. Monolithic operating systems with tons of shared services expose lots to their tenants. Austere hypervisors, the ones with small API surface areas, basically implement a microkernel interface yet both expose significantly more surface area and offer a significantly worse guest experience than microkernels. That is why high security systems designed for multi-level security for shared tenants that need to protect against state actors use microkernels instead of hypervisors.
> That is why high security systems designed for multi-level security for shared tenants
When you say "high security" do you mean Confidential Computing workloads run by Trusty (Enclave) / Virtee (Realm) etc? If so, aren't these system limited in what they can do, as in, there usually is another full-blown OS that's running the user-facing bits?
> that need to protect against state actors
This is a very high bar for a software-only solution (like a microkernel) to meet? In my view, open hardware specification, like OpenTitan, in combination with small-ish software TCB, make it hard for state actors (even if not impossible).