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 77B4DC433F5 for ; Mon, 27 Aug 2018 13:48:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26141208B6 for ; Mon, 27 Aug 2018 13:48:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 26141208B6 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 S1727455AbeH0Rew (ORCPT ); Mon, 27 Aug 2018 13:34:52 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:43298 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727113AbeH0Rew (ORCPT ); Mon, 27 Aug 2018 13:34:52 -0400 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7RDiFoK137776 for ; Mon, 27 Aug 2018 09:48:08 -0400 Received: from e15.ny.us.ibm.com (e15.ny.us.ibm.com [129.33.205.205]) by mx0a-001b2d01.pphosted.com with ESMTP id 2m4gqn4u96-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 27 Aug 2018 09:48:08 -0400 Received: from localhost by e15.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) Mon, 27 Aug 2018 09:48:03 -0400 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w7RDm0BF29229068 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 27 Aug 2018 13:48:00 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C46A7AC05B; Mon, 27 Aug 2018 09:48:05 -0400 (EDT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3CAA0AC059; Mon, 27 Aug 2018 09:48:04 -0400 (EDT) Received: from oc8043147753.ibm.com (unknown [9.60.75.213]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP; Mon, 27 Aug 2018 09:48:04 -0400 (EDT) Subject: Re: [PATCH v9 12/22] s390: vfio-ap: sysfs interfaces to configure control domains To: Cornelia Huck Cc: Halil Pasic , Christian Borntraeger , pmorel@linux.ibm.com, 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> <20180823122525.02fc4af3.cohuck@redhat.com> <20180827103316.4e7fbc10.cohuck@redhat.com> From: Tony Krowiak Date: Mon, 27 Aug 2018 09:47:58 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <20180827103316.4e7fbc10.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 18082713-0068-0000-0000-0000033032CC X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009620; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01079609; UDB=6.00556815; IPR=6.00859593; MB=3.00022957; MTD=3.00000008; XFM=3.00000015; UTC=2018-08-27 13:48:05 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18082713-0069-0000-0000-0000458820D3 Message-Id: <65cb82b5-85ce-1831-5b2a-719d2cf27be8@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-27_06:,, 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=8.0.1-1807170000 definitions=main-1808270147 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/27/2018 04:33 AM, Cornelia Huck wrote: > On Thu, 23 Aug 2018 10:16:59 -0400 > Tony Krowiak wrote: > >> On 08/23/2018 06:25 AM, Cornelia Huck wrote: >>> On Wed, 22 Aug 2018 15:16:19 -0400 >>> Tony Krowiak wrote: >>> >>>> One of the things I suggested in a private conversation with Christian >>>> earlier >>>> today was to provide an additional rw sysfs attribute - a boolean - that >>>> indicates >>>> whether all usage domains should also be control domains. The default >>>> could be >>>> true. This would allow one to configure guests with usage-only domains >>>> as well >>>> as satisfy the convention. >>> Would this additional attribute then control "add usage domains to the >>> list of control domains automatically", or "don't allow to add a usage >>> domain if it has not already been added as a control domain"? >> It was just a proposal that wasn't really discussed at all, but this >> attribute would add usage domains to the list of control domains >> automatically if set to one. That would be the default behavior which >> would be turned off by manually setting it to zero. > If we want to do something like that, having it add the usage domains > automatically sounds like the more workable alternative. What I like > about this is that we make it explicit that we change the masks beyond > what the admin explicitly configured, and provide a knob to turn off > that behaviour. So, are you saying I should go ahead and implement this? > >>> One thing I'm still unsure about is how libvirt comes into the picture >>> here. Will it consume the setting, or actively manipulate it? >> libvirt is not in the picture. The only thing libvirt does is identify >> which mediated matrix device (i.e., UUID) is to be used by the guest. >> >>> [In general, I'm not very clear about how libvirt will interact with the >>> whole infrastructure...] >> The libvirt domain XML will only specify the UUID of the matrix device >> to be used by the guest. Consequently, libvirt will insert the device >> statement for the vfio-ap device into the QEMU command line: >> >> -device vfio-ap,syfsdev={path-to-mdev} >> >> All configuration of the mediated device, including the proposed attribute >> above, is handled via sysfs attributes. > So, basically, libvirt will only consume what the admin has already > configured? Yes. >