Messages in this thread | | | Date | Thu, 28 Feb 2019 14:52:54 +0100 | From | Cornelia Huck <> | Subject | Re: [PATCH v4 1/7] s390: ap: kvm: add PQAP interception for AQIC |
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On Thu, 28 Feb 2019 14:16:09 +0100 Pierre Morel <pmorel@linux.ibm.com> wrote:
> On 28/02/2019 12:22, Cornelia Huck wrote:
> > So, to summarize, the function should do: > > - Is userspace supposed to emulate everything (!ECA_APIE)? Return > > -EOPNOTSUPP to hand control to it. > > - We are now interpreting the instruction in KVM. Do common checks > > (PSTATE etc.) and inject exceptions, if needed. > > - Now look at the fc; if there's a handler for it, call that; if not > > (case does not attempt to call a specific handler, or no handler > > registered), inject a specification exception. (Do we want pre-checks > > like for facility 65 here, or in the handler?) > > > > That response code 0x01 thingy probably needs to go into the specific > > handler function, if anywhere (don't know the semantics, sorry). > > What do you mean with specific handler function? > > If you mean a switch around the FC with static function's call, I agree, > if you mean a jump into a hook I do not agree.
Ah, ok; so each case (that we want to handle) should call into a subhandler that does { (... check things like facilities ...) if (!specific_hook) inject_specif_excp_and_return(); ret = specific_hook(); if (ret) set_resp_code_0x01(); // or in specific_hook()? }
? > > > > Question: Will the handlers for the individual fcs need to generate > > different exceptions on their own? I.e., do they need to do injections > > themselves, or should the calling function possibly inject an exception > > on error? > > There are some specificities.
Ok, should probably done in the subhandlers?
(I hope I don't muddy the waters too much; but basically, I'm poking around with a stick in the dark :)
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