Messages in this thread | | | Subject | Re: [RFC 19/19] s390/facilities: enable AP facilities needed by guest | From | Christian Borntraeger <> | Date | Fri, 3 Nov 2017 09:49:46 +0100 |
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On 11/03/2017 09:14 AM, Harald Freudenberger wrote: > I talked with the firmware guys about this. > The answer is that the AP 3 instructions (NQAP, DQAP, PQAP) are always available.
That is true for basic mode and LPAR, but certainly not for z/VM or KVM guests.
> Tony is right with the facility bits. > facility bit 15 tells if the T bit is supported with the PQAP(TAPQ) subcommand, > facility bit 12 tells if the PQAP(QCI) subcommand is available. > > As far as I could discover the AP instructions where optional on some older machines. > This may be the reason why zVM throws an exception if there is no AP device assigned. > However, for all machines still in service the AP instructions are available at al time.
We have to distinguish LPARs and 2nd level guests under KVM/z/VM. For those 2nd level guests there are configurations out there TODAY that do not support PQAP and friends.
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