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=-0.8 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 3CF00C5CFEB for ; Mon, 9 Jul 2018 15:50:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F26E92075B for ; Mon, 9 Jul 2018 15:50:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F26E92075B 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 S933710AbeGIPuO (ORCPT ); Mon, 9 Jul 2018 11:50:14 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36578 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933351AbeGIPuJ (ORCPT ); Mon, 9 Jul 2018 11:50:09 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w69Fn4fv099032 for ; Mon, 9 Jul 2018 11:50:09 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2k48jg8nry-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 09 Jul 2018 11:50:09 -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) Mon, 9 Jul 2018 16:50:03 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w69Fo1PB23199974 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 9 Jul 2018 15:50:01 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 746BC4C059; Mon, 9 Jul 2018 18:50:24 +0100 (BST) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AADDB4C044; Mon, 9 Jul 2018 18:50:23 +0100 (BST) Received: from oc0155643701.ibm.com (unknown [9.152.224.111]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 9 Jul 2018 18:50:23 +0100 (BST) Subject: Re: [PATCH v6 21/21] s390: doc: detailed specifications for AP virtualization To: pmorel@linux.ibm.com, Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.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, Tony Krowiak References: <1530306683-7270-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1530306683-7270-22-git-send-email-akrowiak@linux.vnet.ibm.com> <753c5e17-c241-580d-6e3a-a3c3159d44a8@linux.ibm.com> <0580735b-8813-f860-a2ac-654d82203b35@linux.ibm.com> From: Halil Pasic Date: Mon, 9 Jul 2018 11:50:00 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <0580735b-8813-f860-a2ac-654d82203b35@linux.ibm.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: 18070915-0028-0000-0000-000002D9BBB9 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18070915-0029-0000-0000-00002391589C Message-Id: <2e30976a-a2d0-c407-c491-acde565b63f1@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-07-09_07:,, 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=8.0.1-1806210000 definitions=main-1807090181 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/09/2018 05:21 AM, Pierre Morel wrote: > On 03/07/2018 01:10, Halil Pasic wrote: >> >> >> On 06/29/2018 11:11 PM, Tony Krowiak wrote: >>> This patch provides documentation describing the AP architecture and >>> design concepts behind the virtualization of AP devices. It also >>> includes an example of how to configure AP devices for exclusive >>> use of KVM guests. >>> >>> Signed-off-by: Tony Krowiak >> >> I don't like the design of external interfaces except for: >> * cpu model features, and >> * reset handling. >> >> In particular: >> >> > ...snip... > >> 4) If I were to act out the role of the administrator, I would prefer to think of >> specifying or changing the access controls of a guest in respect to AP (that is >> setting the AP matrix) as a single atomic operation -- which either succeeds or fails. >> >> The operation should succeed for any valid configuration, and fail for any invalid >> on. >> >> The current piecemeal approach seems even less fitting if we consider changing the >> access controls of a running guest. AFAIK changing access controls for a running >> guest is possible, and I don't see a reason why should we artificially prohibit this. >> >> I think the current sysfs interface for manipulating the matrix is good for >> manual playing around, but I would prefer having an interface that is better >> suited for programs (e.g. ioctl). > > I disagree with using ioctl. Why? What speaks against ioctl? > I agree that the current implementation is not right. > The configuration of APM and AQM should always be guarantied as coherent > within the host but it can be done doing the right checks when using the sysfs. > I'm glad we agree on this one at least. Regards, Halil