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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 6090CC433E0 for ; Thu, 9 Jul 2020 13:58:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 410732074B for ; Thu, 9 Jul 2020 13:58:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727981AbgGIN6P (ORCPT ); Thu, 9 Jul 2020 09:58:15 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:29752 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726729AbgGIN6O (ORCPT ); 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Thu, 09 Jul 2020 13:58:10 +0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 069Dw8Ht57082042 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 9 Jul 2020 13:58:08 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7F64AAE04D; Thu, 9 Jul 2020 13:58:08 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 11775AE055; Thu, 9 Jul 2020 13:58:08 +0000 (GMT) Received: from oc3016276355.ibm.com (unknown [9.145.34.67]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 9 Jul 2020 13:58:07 +0000 (GMT) Subject: Re: [kvm-unit-tests PATCH v11 8/9] s390x: css: msch, enable test To: Cornelia Huck Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, david@redhat.com, thuth@redhat.com, drjones@redhat.com References: <1594282068-11054-1-git-send-email-pmorel@linux.ibm.com> <1594282068-11054-9-git-send-email-pmorel@linux.ibm.com> <20200709134056.0d267b6c.cohuck@redhat.com> <20200709153055.6f2b5e59.cohuck@redhat.com> <4f861a9c-179b-5376-5f0f-dce30f31da71@linux.ibm.com> <20200709155241.3014e3d6.cohuck@redhat.com> From: Pierre Morel Message-ID: Date: Thu, 9 Jul 2020 15:58:07 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200709155241.3014e3d6.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-07-09_07:2020-07-09,2020-07-09 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 priorityscore=1501 lowpriorityscore=0 clxscore=1015 mlxscore=0 bulkscore=0 spamscore=0 suspectscore=0 adultscore=0 impostorscore=0 malwarescore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007090100 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 2020-07-09 15:52, Cornelia Huck wrote: > On Thu, 9 Jul 2020 15:41:56 +0200 > Pierre Morel wrote: > >> On 2020-07-09 15:30, Cornelia Huck wrote: >>> On Thu, 9 Jul 2020 15:12:05 +0200 >>> Pierre Morel wrote: >>> >>>> On 2020-07-09 13:40, Cornelia Huck wrote: >>>>> On Thu, 9 Jul 2020 10:07:47 +0200 >>>>> Pierre Morel wrote: >>>>> >>>>>> A second step when testing the channel subsystem is to prepare a channel >>>>>> for use. >>>>>> This includes: >>>>>> - Get the current subchannel Information Block (SCHIB) using STSCH >>>>>> - Update it in memory to set the ENABLE bit and the specified ISC >>>>>> - Tell the CSS that the SCHIB has been modified using MSCH >>>>>> - Get the SCHIB from the CSS again to verify that the subchannel is >>>>>> enabled and uses the specified ISC. >>>>>> - If the command succeeds but subchannel is not enabled or the ISC >>>>>> field is not as expected, retry a predefined retries count. >>>>>> - If the command fails, report the failure and do not retry, even >>>>>> if cc indicates a busy/status pending as we do not expect this. >>>>>> >>>>>> This tests the MSCH instruction to enable a channel successfully. >>>>>> Retries are done and in case of error, and if the retries count >>>>>> is exceeded, a report is made. >>>>>> >>>>>> Signed-off-by: Pierre Morel >>>>>> Acked-by: Thomas Huth >>>>>> Reviewed-by: Cornelia Huck >>>>>> --- >>>>>> lib/s390x/css.h | 8 +++-- >>>>>> lib/s390x/css_lib.c | 72 +++++++++++++++++++++++++++++++++++++++++++++ >>>>>> s390x/css.c | 15 ++++++++++ >>>>>> 3 files changed, 92 insertions(+), 3 deletions(-) >>>>> >>>>> (...) >>>>> >>>>>> +/* >>>>>> + * css_msch: enable subchannel and set with specified ISC >>>>> >>>>> "css_enable: enable the subchannel with the specified ISC" >>>>> >>>>> ? >>>>> >>>>>> + * @schid: Subchannel Identifier >>>>>> + * @isc : number of the interruption subclass to use >>>>>> + * Return value: >>>>>> + * On success: 0 >>>>>> + * On error the CC of the faulty instruction >>>>>> + * or -1 if the retry count is exceeded. >>>>>> + */ >>>>>> +int css_enable(int schid, int isc) >>>>>> +{ >>>>>> + struct pmcw *pmcw = &schib.pmcw; >>>>>> + int retry_count = 0; >>>>>> + uint16_t flags; >>>>>> + int cc; >>>>>> + >>>>>> + /* Read the SCHIB for this subchannel */ >>>>>> + cc = stsch(schid, &schib); >>>>>> + if (cc) { >>>>>> + report_info("stsch: sch %08x failed with cc=%d", schid, cc); >>>>>> + return cc; >>>>>> + } >>>>>> + >>>>>> + flags = PMCW_ENABLE | (isc << PMCW_ISC_SHIFT); >>>>>> + if ((pmcw->flags & flags) == flags) { >>>>> >>>>> I think you want (pmcw->flags & PMCW_ENABLE) == PMCW_ENABLE -- this >>>>> catches the case of "subchannel has been enabled before, but with a >>>>> different isc". >>>> >>>> If with a different ISC, we need to modify the ISC. >>>> Don't we ? >>> >>> I think that's a policy decision (I would probably fail and require a >>> disable before setting another isc, but that's a matter of taste). >>> >>> Regardless, I think the current check doesn't even catch the 'different >>> isc' case? >> >> hum, right. >> If it is OK I remove this one. >> And I must rework the same test I do later >> in this patch. > > So, you mean checking for PMCW_ENABLE? Or not at all? > > (I'd check for PMCW_ENABLE.) > - if ((pmcw->flags & flags) == flags) { + if ((pmcw->flags & (PMCW_ISC_MASK | PMCW_ENABLE)) == flags) { report_info("stsch: sch %08x already enabled", schid); return 0; } I keep both, otherwise I return 0 without setting the ISC. then I have another error: retry: /* Update the SCHIB to enable the channel and set the ISC */ + pmcw->flags &= ~(PMCW_ISC_MASK | PMCW_ENABLE); pmcw->flags |= flags; and finaly the same as the first later... - if ((pmcw->flags & flags) == flags) { + if ((pmcw->flags & (PMCW_ISC_MASK | PMCW_ENABLE)) == flags) { report_info("stsch: sch %08x successfully modified after %d retries", schid, retry_count); is better I think. What do you think? -- Pierre Morel IBM Lab Boeblingen