From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5451C43381 for ; Thu, 28 Feb 2019 13:53:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C07722083D for ; Thu, 28 Feb 2019 13:53:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731933AbfB1NxF (ORCPT ); Thu, 28 Feb 2019 08:53:05 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60492 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726003AbfB1NxE (ORCPT ); Thu, 28 Feb 2019 08:53:04 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 17236ABBC5; Thu, 28 Feb 2019 13:53:04 +0000 (UTC) Received: from gondolin (dhcp-192-222.str.redhat.com [10.33.192.222]) by smtp.corp.redhat.com (Postfix) with ESMTP id F16E2620D1; Thu, 28 Feb 2019 13:52:56 +0000 (UTC) Date: Thu, 28 Feb 2019 14:52:54 +0100 From: Cornelia Huck To: Pierre Morel Cc: Christian Borntraeger , Tony Krowiak , alex.williamson@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com Subject: Re: [PATCH v4 1/7] s390: ap: kvm: add PQAP interception for AQIC Message-ID: <20190228145254.2909425e.cohuck@redhat.com> In-Reply-To: References: <1550849400-27152-1-git-send-email-pmorel@linux.ibm.com> <1550849400-27152-2-git-send-email-pmorel@linux.ibm.com> <9f1d9241-39b9-adbc-d0e9-cb702e609cbc@linux.ibm.com> <4dc59125-7f96-cba8-651b-382ed8f8bff8@linux.ibm.com> <8526f468-9a4d-68d2-3868-0dad5ce16f46@linux.ibm.com> <6058a017-6404-af3c-62ef-2452214ac97c@de.ibm.com> <2391adc2-6611-034c-61c5-feb46e2a751b@de.ibm.com> <20190228122251.75b31f62.cohuck@redhat.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Thu, 28 Feb 2019 13:53:04 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 28 Feb 2019 14:16:09 +0100 Pierre Morel 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 :)