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 D1F8CC4321D for ; Thu, 23 Aug 2018 10:41:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8BFF020C07 for ; Thu, 23 Aug 2018 10:41:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8BFF020C07 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729009AbeHWOK1 (ORCPT ); Thu, 23 Aug 2018 10:10:27 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:58506 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727162AbeHWOK1 (ORCPT ); Thu, 23 Aug 2018 10:10:27 -0400 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7NAd4B5073965 for ; Thu, 23 Aug 2018 06:41:20 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2m1suf45w2-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 23 Aug 2018 06:41:20 -0400 Received: from localhost by e06smtp07.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) Thu, 23 Aug 2018 11:41:14 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w7NAfCmu41091074 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 23 Aug 2018 10:41:12 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F39EA4C04E; Thu, 23 Aug 2018 13:41:13 +0100 (BST) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 28E404C046; Thu, 23 Aug 2018 13:41:13 +0100 (BST) Received: from [9.152.224.92] (unknown [9.152.224.92]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 23 Aug 2018 13:41:13 +0100 (BST) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v9 12/22] s390: vfio-ap: sysfs interfaces to configure control domains To: Halil Pasic , Tony Krowiak , Christian Borntraeger , Cornelia Huck Cc: Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com, frankja@linux.ibm.com References: <1534196899-16987-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1534196899-16987-13-git-send-email-akrowiak@linux.vnet.ibm.com> <20180820162317.08bd7d23.cohuck@redhat.com> <660de00a-c403-28c1-4df4-82a973ab3ad5@linux.ibm.com> <20180821172548.57a6c758.cohuck@redhat.com> <82a391ee-85b1-cdc7-0f9b-d37fd8ba8e47@linux.ibm.com> <20180822114250.59a250aa.cohuck@redhat.com> <8bc5f207-f913-825c-f9fc-0a2c7fd280aa@linux.ibm.com> <219b352b-d5a2-189c-e205-82e7f9ae3d64@de.ibm.com> <9ef5fcb9-02e0-88e3-007c-eedb14e6db80@linux.ibm.com> From: Pierre Morel Date: Thu, 23 Aug 2018 12:41:11 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 18082310-0028-0000-0000-000002EEA602 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18082310-0029-0000-0000-000023A7EBDC Message-Id: <56ce7a29-c7ce-1bad-c26b-945b2d8dae4b@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-23_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=435 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808230114 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23/08/2018 11:26, Halil Pasic wrote: > > > On 08/22/2018 09:16 PM, Tony Krowiak wrote: >> On 08/22/2018 01:11 PM, Halil Pasic wrote: >>> >>> >>> On 08/22/2018 05:48 PM, Christian Borntraeger wrote: >>>> On 08/22/2018 05:34 PM, Pierre Morel wrote: >>>>> On 22/08/2018 17:11, Christian Borntraeger wrote: >>>>>> >>>>>> >>>>>> On 08/22/2018 01:03 PM, Pierre Morel wrote: >>>>>>>> That's interesting. >>>>>>>> ... >>>> >>>> So you have changed the code to not automatically make a usage domain a >>>> control domain in the bitfield (and you could still use it as a usage >>>> domain). Correct? Yes. >>> >>> I tested basically the same yesterday, with the same results. >>> >>>> I think this is probably expected. the "usage implies control" seems to >>>> be a convention implemented by HMC (lpar) and z/VM but millicode offers >>>> the bits to have usage-only domains. As LPAR and z/VM will always >>>> enable >>>> any usage-domain to also be a control domain we should do the same. I think it is the reasonable thing to do. >>> >>> I'm fine either way, but slightly prefer higher level management >>> software >>> and not the kernel accommodating this convention. Please, we do not need this in a first version just make it easy stick with what HMC does. >>> with read access to, let's say a regular file. For me, all options >>> (rw, r, and w) >>> do make sense, and if I had to pick the one that makes the least >>> sense I would >>> pick write only. The convention is in these terms making read-only >>> illegal. But >>> should 'usage only domains' ever get identified as something somebody >>> wants to do >>> we can just add an attribute for that. So I'm fine either way. We do not need to introduce new features now. regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany