Re: Privilege Levels Below User

On Sun, 09 Jun 2024 14:13:25 GMT, Scott Lurndal wrote:

Lawrence D'Oliveiro <ldo@nz.invalid> writes:

On Sat, 8 Jun 2024 17:37:46 +0000, MitchAlsup1 wrote:
>

VAX was before common era Hypervisors, do you think VAX could have
supported secure mode and hypervisor with their 4 levels ??

>
“Virtualization” was bandied about in the 1980s more as an idle,
theoretical concept rather than a practical one.

 
I'm quite sure that IBM would disagree with this statement.

I’m sure they would. But they invented virtualization in CP/CMS because
their attempt at an “interactive timesharing” system, CMS, was only
single-user. Rather than make it multiuser, they simply invented CP as a
big hack to run multiple copies of CMS, so each user felt they had an
entire machine to themself.

There were some privilege holes in that, as well.