It's kind of ironic in the end.
The Mainframe was there decades ago, with the multi-tasking, multi-users functionality and probably the best Hypervisor ever coded.
And even now, with the powerful Mainframe cpu IBM can manufactures, if I try to code something that will try to sneek out of my area, MVS will "spit" me out with an abend-code 0C4, which means : "Sorry buddy, you are not authorized to read this region".
Intel should have learned from the Big Iron...