Messages in this thread | | | Subject | Re: [PATCH v4 1/7] s390: ap: kvm: add PQAP interception for AQIC | From | Pierre Morel <> | Date | Thu, 28 Feb 2019 15:14:13 +0100 |
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On 28/02/2019 14:52, Cornelia Huck wrote: > 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()? > } > > ?
Yes something in this direction.
> >>> >>> 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 :) >
No problem, it is OK. My first idea was to make only changes associated with PQAP/AQIC. We already should have done it for all PQAP functions so it is decided that we will do it now as Christian proposed.
Regards, Pierre
-- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
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