Re: [seL4] Userland components in Ring 1/2 (where kernel is in ring 0) to provide protection from less trusted components

On 18 Sep 2020, at 10:35, William ML Leslie <william.leslie.ttg@gmail.com<mailto:william.leslie.ttg@gmail.com>> wrote: Not to mention that the multics driver rings are a fairly dark corner of the processor these days, since no operating system appears to make use of 1 and 2, so nobody is inspecting them for hardware bugs. Correct, for the basic reason that there is no benefit from running things in rings 1 or 2, you can just run them at ring 0. Also, you can safely expect poor performance (eg systenter/sysexit aren’t supported). Gernot