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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 1BD5DC76192 for ; Wed, 17 Jul 2019 12:53:15 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E6B012173E for ; Wed, 17 Jul 2019 12:53:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E6B012173E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56796 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hnjQo-0000zv-6c for qemu-devel@archiver.kernel.org; Wed, 17 Jul 2019 08:53:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39867) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hnjQd-0000Zo-Bj for qemu-devel@nongnu.org; Wed, 17 Jul 2019 08:53:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hnjQc-0004Z6-0r for qemu-devel@nongnu.org; Wed, 17 Jul 2019 08:53:03 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:2558 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hnjQb-0004X5-RG for qemu-devel@nongnu.org; Wed, 17 Jul 2019 08:53:01 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6HCpPJm054218 for ; Wed, 17 Jul 2019 08:53:00 -0400 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0b-001b2d01.pphosted.com with ESMTP id 2tt0pn1fp5-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 17 Jul 2019 08:53:00 -0400 Received: from localhost by e11.ny.us.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) Wed, 17 Jul 2019 13:52:56 +0100 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x6HCqtsb52036062 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 17 Jul 2019 12:52:55 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 19D8AAC05B; Wed, 17 Jul 2019 12:52:55 +0000 (GMT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D69E0AC059; Wed, 17 Jul 2019 12:52:54 +0000 (GMT) Received: from [9.60.89.78] (unknown [9.60.89.78]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP; Wed, 17 Jul 2019 12:52:54 +0000 (GMT) To: Christian Borntraeger , Cornelia Huck References: <20190708125433.16927-1-cohuck@redhat.com> <20190708125433.16927-2-cohuck@redhat.com> <58b28817-58e5-1cba-6f71-a35093be5cb6@de.ibm.com> <0dd71cfe-a9e9-7ac3-523e-065f05479a57@linux.ibm.com> <20190710102041.6be31940.cohuck@redhat.com> <20190716172002.77863317.cohuck@redhat.com> <20190717105435.64047ca3.cohuck@redhat.com> From: Collin Walling Date: Wed, 17 Jul 2019 08:52:54 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19071712-2213-0000-0000-000003B23E9D X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011445; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000286; SDB=6.01233450; UDB=6.00649930; IPR=6.01014775; MB=3.00027759; MTD=3.00000008; XFM=3.00000015; UTC=2019-07-17 12:52:58 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19071712-2214-0000-0000-00005F47D2AA Message-Id: <60169464-240f-d5e3-209f-9c5371ee3e6f@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-07-17_05:, , 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-1907170155 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.158.5 Subject: Re: [Qemu-devel] [qemu-s390x] [PATCH for-4.1 1/2] s390x/pci: add some fallthrough annotations X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Hildenbrand , Stefan Weil , qemu-devel@nongnu.org, Halil Pasic , qemu-s390x@nongnu.org, Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 7/17/19 5:27 AM, Christian Borntraeger wrote: > > > On 17.07.19 10:54, Cornelia Huck wrote: >> On Tue, 16 Jul 2019 14:34:22 -0400 >> Collin Walling wrote: >> >>> On 7/16/19 11:20 AM, Cornelia Huck wrote: >>>> On Wed, 10 Jul 2019 10:20:41 +0200 >>>> Cornelia Huck wrote: >>>> >>>>> On Tue, 9 Jul 2019 18:55:34 -0400 >>>>> Collin Walling wrote: >>>>> >>>>>> On 7/8/19 9:23 AM, Christian Borntraeger wrote: >>>>>>> >>>>>>> >>>>>>> On 08.07.19 14:54, Cornelia Huck wrote: >>>>>>>> According to the comment, the bits are supposed to accumulate. >>>>>>>> >>>>>>>> Reported-by: Stefan Weil >>>>>>>> Fixes: 5d1abf234462 ("s390x/pci: enforce zPCI state checking") >>>>>>>> Signed-off-by: Cornelia Huck >>>>>>> >>>>>>> This patch does not change behaviour, so it is certainly not wrong. >>>>>>> >>>>>>> So lets have a look at if the bug report was actually a real bug or >>>>>>> just a missing annotation. >>>>>>> >>>>>>>> --- >>>>>>>> hw/s390x/s390-pci-inst.c | 2 ++ >>>>>>>> 1 file changed, 2 insertions(+) >>>>>>>> >>>>>>>> diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c >>>>>>>> index 61f30b8e55d2..00235148bed7 100644 >>>>>>>> --- a/hw/s390x/s390-pci-inst.c >>>>>>>> +++ b/hw/s390x/s390-pci-inst.c >>>>>>>> @@ -1209,8 +1209,10 @@ int stpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar, >>>>>>>> * FH Enabled bit is set to one in states of ENABLED, BLOCKED or ERROR. */ >>>>>>>> case ZPCI_FS_ERROR: >>>>>>>> fib.fc |= 0x20; >>>>>>>> + /* fallthrough */ >>>>>>> >>>>>>> This is correct, in case of an error we are also blocked. >>>>>>> >>>>>> >>>>>> Agreed. This is definitely correct based on our architecture. >>>>>> >>>>>>>> case ZPCI_FS_BLOCKED: >>>>>>>> fib.fc |= 0x40; >>>>>>>> + /* fallthrough */ >>>>>>> >>>>>>> I think this is also correct, but it would be good if Collin could verify. >>>>>>> >>>>>> >>>>>> I failed to find anything to support setting the function control >>>>>> enabled bit when the function state is in error / blocked. I'm >>>>>> assuming this might be some QEMU hack to get things working? I'll have >>>>>> to dive further to understand why this was done this way, as it doesn't >>>>>> align with how the s390x architecture is documented. It's confusing. >>>>> >>>>> Might this also be a real issue? Not matching the architecture is not a >>>>> good sign... >>>> >>>> Friendly ping. If we still want to have this patch or a fix in 4.1, we >>>> need to find out soon... >>>> >>> >>> Let's take it for now. >>> >>> Acked-by: Collin Walling >>> >> >> Just to be clear: You think that the current code is correct AFAYCS? > > I also looked into this again. > There is a possibility to also be in disabled state. > From what I can see, it makes sense that blocked and error belong to the enable state > so the patch seems correct. > Yes I agree. The material I referenced required me to look over a few times and ask around a bit. The patch is good. Apologies for my ambiguous response.