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    SubjectRe: [PATCH v9 22/22] s390: doc: detailed specifications for AP virtualization
    On Tue, 21 Aug 2018 20:54:49 +0200
    Halil Pasic <pasic@linux.ibm.com> wrote:

    > On 08/20/2018 10:16 PM, Tony Krowiak wrote:
    > >> Does the SIE complain if you specify a control
    > >> domain that the host does not have access to (I'd guess so)?
    > >
    > > The SIE does not complain if you specify a domain to which the host - or a
    > > lower level guest - does not have access. The firmware performs a logical
    > > AND of the guest's and hosts's - or lower level guest's - APMs, AQMs and ADMs
    >
    > Rather a bit-wise AND, I guess (of the same type masks corresponding to Guest 1 and
    > Guest 2). The result of a logical AND is a logical value (true or false) as
    > far as I remember.
    >
    > > to create effective masks EAPM, EAQM and EADM. Only devices corresponding to
    > > the bits set in the EAPM, EAQM and EADM will be accessible by the guest.
    >
    > I'm not sure what is the intended meaning of 'the SIE complains'. If it means
    > getting out of (SIE when interpreting lets say an NQAP under the discussed
    > circumstances) with some sort of error code, I think Tony's answer, ' SIE does not complain'
    > makes a lot of sense. It's the guest that's is trying to stretch further than
    > the blanket reaches, and it's the guest that needs to be educated on this fact.

    Yep, that's what I meant. If the hypervisor can call the SIE with that
    config, but the guest gets an error if it tries to use something that
    it cannot use, that's fine.

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