Idk for sure, haven’t properly looked into it. Just read in passing that mainframes were doing this kind of thing for ages. Mainframe software generally has stuff that’s pretty weird by today’s standards, I need to read up on it sometime.

Wikipedia says regarding z/OS:

z/OS has a Workload Manager (WLM) and dispatcher which automatically manages numerous concurrently hosted units of work running in separate key-protected address spaces according to dynamically adjustable goals. This capability inherently supports multi-tenancy within a single operating system image. However, modern IBM mainframes also offer two additional levels of virtualization: LPARs and (optionally) z/VM.