> Key0 is much much more dangerous than supervisor state (IMHO)

Interesting. I never thought of that, but I agree. Which is the more likely
error?

- You accidentally code some privileged instruction that you did not intend?
- You code the wrong register number in an instruction, or destroy or forget
to initialize the contents of a register (at least on some code paths), or a
register gets incremented too far?

Charles


-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[email protected]] On
Behalf Of Binyamin Dissen
Sent: Sunday, June 9, 2019 11:48 PM
To: [email protected]
Subject: Re: Any way to set the PKM in "open code".

On Sun, 9 Jun 2019 20:15:40 -0400 Rob Schramm <[email protected]> wrote:

:>I suspect John's answer will be
:>1) because it's cool to try new things

Well, to do that he could encapsulate this code in a PC-CP with an altered
AKM. 

:>2) because I want to limit the destruction if it goes wrong.

Key0 is much much more dangerous than supervisor state (IMHO)

:>Waiting for the real answer,
:>Rob
:>
:>On Sun, Jun 9, 2019, 6:22 PM Binyamin Dissen <[email protected]>
:>wrote:
:>
:>> On Fri, 7 Jun 2019 08:57:38 -0500 John McKown <
:>> [email protected]>
:>> wrote:
:>>
:>> :>I am not finding this. I want to change the PKM for my running, APF
:>> :>authorized, program to include key 0. Why? So that I can switch in and
:>> out
:>> :>of key 0 using an SPKA instruction rather than MODESET. But mainly so
:>> that
:>> :>I can use the MVCSK and MVCDK instructions to read & update key 0,
fetch
:>> :>protected, storage without going into key 0.
:>>
:>> :>Or am I just being silly (again)?
:>>
:>> Why not simply run supervisor state which allows access to all keys?

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