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_HELO_NONE,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 48E70C46460 for ; Thu, 16 May 2019 13:37:28 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0E8ED20833 for ; Thu, 16 May 2019 13:37:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0E8ED20833 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 ([127.0.0.1]:57928 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hRGZb-0008TJ-7I for qemu-devel@archiver.kernel.org; Thu, 16 May 2019 09:37:27 -0400 Received: from eggs.gnu.org ([209.51.188.92]:44141) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hRGYe-0007lY-2n for qemu-devel@nongnu.org; Thu, 16 May 2019 09:36:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hRGYb-000386-1Y for qemu-devel@nongnu.org; Thu, 16 May 2019 09:36:28 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:50968) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hRGYZ-0002lG-0P for qemu-devel@nongnu.org; Thu, 16 May 2019 09:36:24 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4GDYEWl108229 for ; Thu, 16 May 2019 09:36:13 -0400 Received: from e16.ny.us.ibm.com (e16.ny.us.ibm.com [129.33.205.206]) by mx0a-001b2d01.pphosted.com with ESMTP id 2sh8hrsaah-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 16 May 2019 09:36:11 -0400 Received: from localhost by e16.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) Thu, 16 May 2019 14:35:57 +0100 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4GDZuiY38928724 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 May 2019 13:35:56 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A0CC3AC05F; Thu, 16 May 2019 13:35:56 +0000 (GMT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 91FD2AC05E; Thu, 16 May 2019 13:35:56 +0000 (GMT) Received: from [9.56.58.99] (unknown [9.56.58.99]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 16 May 2019 13:35:56 +0000 (GMT) To: Cornelia Huck , David Hildenbrand References: <1556749903-19221-1-git-send-email-walling@linux.ibm.com> <09293a1c-d000-83a8-46b8-b97ad4fa9774@de.ibm.com> <56e3ace1-6e48-0e20-47d5-b07ac6dfcf31@redhat.com> <20190513134637.3d8bb275.cohuck@redhat.com> <898144e3-615e-5074-fb68-bf9995c64609@de.ibm.com> <155d2ca3-6a48-c99a-fe42-dca8e3fd4344@redhat.com> <066c7470-94a3-a922-9a12-1ca42e474c51@de.ibm.com> <20190514104934.6bba9232.cohuck@redhat.com> <47f7134b-338f-0207-88ae-4c1969be3786@redhat.com> <13b0f0b2-f7c7-01fb-0e17-92bd47d9c346@de.ibm.com> <00b5d031-227b-38f7-9512-e36c3b655c62@de.ibm.com> <27bd36e1-a102-e793-6a61-3e7acb6f1255@de.ibm.com> <078b7bcd-de03-743d-a150-456be0b09362@redhat.com> <20190514113005.2d0c2b1c.cohuck@redhat.com> From: Collin Walling Date: Thu, 16 May 2019 09:35:56 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190514113005.2d0c2b1c.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-cbid: 19051613-0072-0000-0000-0000042E6DE4 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011105; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000285; SDB=6.01204155; UDB=6.00632118; IPR=6.00985085; MB=3.00026918; MTD=3.00000008; XFM=3.00000015; UTC=2019-05-16 13:36:00 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19051613-0073-0000-0000-00004C3EA838 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-05-16_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-1905160091 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.156.1 Subject: Re: [Qemu-devel] [qemu-s390x] [PATCH v4] s390: diagnose 318 info reset and migration support X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mst@redhat.com, qemu-devel@nongnu.org, pasic@linux.ibm.com, Christian Borntraeger , qemu-s390x@nongnu.org, pbonzini@redhat.com, rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 5/14/19 5:30 AM, Cornelia Huck wrote: > On Tue, 14 May 2019 11:27:32 +0200 > David Hildenbrand wrote: > >> On 14.05.19 11:25, Christian Borntraeger wrote: >>> >>> >>> On 14.05.19 11:23, Christian Borntraeger wrote: >>>> >>>> >>>> On 14.05.19 11:20, David Hildenbrand wrote: >>>>> On 14.05.19 11:10, Christian Borntraeger wrote: >>>>>> >>>>>> >>>>>> On 14.05.19 10:59, David Hildenbrand wrote: > >>>>>>> We can >>>>>>> >>>>>>> 1. Fail to start with #cpus > 240 when diag318=on >>>>>>> 2. Remove the error once we support more than one SCLP response page >>>>>>> >>>>>>> Or >>>>>>>b >>>>>>> 1. Allow to start with #cpus > 240 when diag318=on, but indicate only >>>>>>> 240 CPUs via SCLP >>>>>>> 2. Print a warning >>>>>>> 3. Remove the restriction and the warning once we support more than one >>>>>>> SCLP response page >>>>>>> >>>>>>> While I prefer the second approach (similar to defining zPCI devices >>>>>>> without zpci=on), I could also live with the first approach. >>>>>> >>>>>> I prefer approach 1. >>>>>> >>>>> >>>>> Isn't approach #2 what we discussed (limiting sclp, but of course to 247 >>>>> CPUs), but with an additional warning? I'm confused. >>>> >>>> Different numbering interpretion. I was talking about 1 = "Allow to start with #cpus > 240 when diag318=on, but indicate only >>>> 240 CPUs via SCLP" >>> >>> So yes, variant 2 when I use your numbering. The only question is: do we need >>> a warning? It probably does not hurt. >> >> After all, we are talking about 1 VCPU that the guest can only use by >> indirect probing ... I leave that up to Collin :) > > I'd prefer a warning... even if it is a corner case, I think it's > better to be explicit instead of silent. > Thanks for the discussion. I'll implement diag318 as a CPU feature again and adjust the max_cpu handling (to 247 now instead of 240). Question: should diag318 be enabled by default for current CPU models? What should we do in the case where diag318=on but KVM does not support handling? I am not familiar with how close QEMU and KVM versions stay in sync.