This group is for all folks running the original IBM VM/370 Release 6 operating system (or later (e.g. VMTCE (Community Edition)) on Hercules. Like the other early IBM operating systems this version has always been in the public domain and so can be freely distributed. The base version as supplied by IBM is lacking in many facilities. IBM solved this by providing additional extension products which were licensed and so are not available. There are however many user enhancements available which can be installed. In addition, in order to get users up and running quickly updated "releases" of VM/370 included the most popular updates are available for download, so novices can start to learn VM without having to delve into the system internals. It is intended that this wiki will provide information on the base release and these updates.
The available versions are here :-
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Re: Can a VM machine ...
On Sat, 19 Nov 2022 at 22:44, Fish Fish <david.b.trout@...> wrote: > Tony Harminc wrote: > > > What it does do is make the architecture no longer virtualizable > > (without some feature like
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Tony Harminc
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#4750
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Re: Can a VM machine ...
Tony Harminc wrote: [...] Thank you. Eh? How so? I'm not following you. What does that have to do with your claim that the introduction of new instructions that weren't defined in the original
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Fish Fish
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#4749
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Re: Can a VM machine ...
OK, fair enough. What it does do is make the architecture no longer virtualizable (without some feature like SIE). This 100% virtualizable feature (even for privileged states, and for that matter I/O)
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Tony Harminc
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#4748
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Re: Can a VM machine ...
Tony Harminc wrote: Precisely. <snip; EPSW = Extract PSW instruction> But only if/when specifically requested via enabling that specific Hercules facility (256): FACILITY ENABLE HERC_370_EXTENSION
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Fish Fish
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#4747
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Re: Can a VM machine ...
In my view the key to all this is that there is no way for a program running in CMS (or any guest in a VM) to discover what the real PSW is, even if they are in virtual supervisor state. In S/370
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Tony Harminc
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#4746
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Re: Can a VM machine ...
Bob Bolch wrote: Precisely! The CMS user may *think* (believe) it is running in supervisor state, but in actuality it is not. It's "virtual" PSW (saved/maintained in its VM [user?] block) indicates
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Fish Fish
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#4745
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Re: Can a VM machine ...
Aaron Finerman wrote: Correct. Even your PSW. Well, what you say next makes me question that. Their virtual PSW indicates supervisor state, yes. But their *real* (actual) PSW is still in problem
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Fish Fish
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#4744
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Re: Can a VM machine ...
Not really. Supervisor state is virtualized for the CMS user. When an instruction requiring supervisor state is executed in a CMS machine, a privop occurs and CP is given control to simulate the
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Bob Bolch
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#4743
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Re: Can a VM machine ...
When you run under VM, you are in a virtual machine and everything is virtualized. No one on this forum needs a lesson on that. Applications running under CMS are given control in supervisor state by
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Aaron Finerman
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#4742
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Re: Can a VM machine ...
Aaron Finerman wrote: Then your knowledge needs updating. ;-) CMS *thinks* it is running in supervisor state, but it actually doesn't. It simply runs in *virtualized* supervisor state. It *actually*
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Fish Fish
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#4741
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Re: Can a VM machine ...
I just asked because no documentation I could find says that " diagnose 8 instructions executed in supervisor state" can be sent to Hercules. Bob
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Bob Bolch
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#4740
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Re: Can a VM machine ...
"CMS executes in virtual supervisor state; so do applications you run under CMS. At the same time, CP is running in real problem state. This means that your virtual machine and the programs you run
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Joe Monk
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#4739
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Re: Can a VM machine ...
To the best my knowledge, CMS always runs in supervisor state. But it does not run with key zero. Best regards,
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Aaron Finerman
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#4738
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Re: Can a VM machine ...
Bob Bolch wrote: Indeed! -- *IF* -- CMS's or other virtual machines' DIAG 8 instructions would end up being passed to Hercules for processing, but why would that happen? The Diagnose instruction is a
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Fish Fish
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#4737
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Re: Can a VM machine ...
Bertram Moshier wrote: Yes. It can be done either indirectly if there's no Hercules DIAG 8 support in CP or directly if there is. If CP has support to talk to Hercules via DIAG 8 (and I believe Dave
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Fish Fish
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#4736
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Re: Can a VM machine ...
From: hercules-390@... [mailto:hercules-390@...] On Behalf Of Dave Wade Sent: Tuesday, September 16, 2008 22:16 To: hercules-390@... Subject: RE: [hercules-390] Automation form the Operating system to
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Joe Monk
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#4735
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Re: Can a VM machine ...
Hi, I thought only CP ran in supervisor state and everything else runs in problem state on the physical system. Thus Diag 8 in a virtual system can't get to Herculesn but only to CP. While CP diag 8
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Bertram Moshier
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#4734
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Re: Can a VM machine ...
Dave, How does this mod 10 work? I'm assuming you don't mean Diagnose 10. Isn't diagnose x'0010' to release pages? Bert.
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Bertram Moshier
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#4733
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Re: Can a VM machine ...
Yep ... and your question was: :) You can easily write a callable interface for your backup program to switch to supervisor key and issue DIAG 8. With the hercules CP mod and the config option I
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Joe Monk
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#4732
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Re: Can a VM machine ...
Hello Joe, Yes; but by CP (DMK) not aCMS program. I say this because diag 8 from a virtual system is for issuing CP command. Inside DMK/CP a diag 8 would go to Hercules. Bert
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Bertram Moshier
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#4731
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