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 DA9D3C43381 for ; Fri, 1 Mar 2019 15:32:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADB6E2084D for ; Fri, 1 Mar 2019 15:32:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388916AbfCAPcl (ORCPT ); Fri, 1 Mar 2019 10:32:41 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:54138 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388109AbfCAPck (ORCPT ); Fri, 1 Mar 2019 10:32:40 -0500 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x21FUhYB026850 for ; Fri, 1 Mar 2019 10:32:39 -0500 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qy5frq3m3-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 01 Mar 2019 10:32:39 -0500 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 1 Mar 2019 15:32:33 -0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x21FWVR928377114 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 1 Mar 2019 15:32:31 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C3EB34203F; Fri, 1 Mar 2019 15:32:31 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1A5BF4204B; Fri, 1 Mar 2019 15:32:31 +0000 (GMT) Received: from [9.152.224.140] (unknown [9.152.224.140]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 1 Mar 2019 15:32:31 +0000 (GMT) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v4 1/7] s390: ap: kvm: add PQAP interception for AQIC To: Cornelia Huck , Christian Borntraeger Cc: 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 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> <20190228145254.2909425e.cohuck@redhat.com> <261a1e22-3703-21a4-e33d-e737651e7d89@linux.ibm.com> <3fedbde5-ef83-c67e-6352-fd492f258009@linux.ibm.com> <20190301133609.3ee469dc.cohuck@redhat.com> From: Pierre Morel Date: Fri, 1 Mar 2019 16:32:30 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190301133609.3ee469dc.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19030115-0008-0000-0000-000002C68FF9 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19030115-0009-0000-0000-00002232E62C Message-Id: <7fab18c4-9781-b776-5fd9-250ba19cafe5@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-03-01_11:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903010108 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/03/2019 13:36, Cornelia Huck wrote: > On Fri, 1 Mar 2019 13:05:54 +0100 > Christian Borntraeger wrote: > >> On 01.03.2019 13:03, Pierre Morel wrote: >>> On 28/02/2019 15:14, Pierre Morel wrote: >>>> On 28/02/2019 14:52, Cornelia Huck wrote: >>>>> 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()? >>>>> } >>>>> >>>>> ? >>>> >>>> Yes something in this direction. >>> >>> Sorry, after reflection, no, we do not want to change the previous behavior so we only handle the AQIC case. >> >> I think what you wanted to say is the following: >> Today (without the patch set) we will answer PQAP with an exception. >> With this patch set we want to handle FC==3, but nothing else. So for anything FC!=3 we >> will continue to return an exception? >> >> Correct? Yes correct. Thanks for the much preciser explanation. >> > > That sounds reasonable; but I don't see how this conflicts with my > proposal? Just don't introduce a subfunction for fc != 3... > Correct too, it does not conflict, as you said it is just not introduce subfunctions. Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany