From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751820AbeFEMk6 (ORCPT ); Tue, 5 Jun 2018 08:40:58 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:57574 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751687AbeFEMky (ORCPT ); Tue, 5 Jun 2018 08:40:54 -0400 Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v5 10/13] s390: vfio-ap: sysfs interface to view matrix mdev matrix To: 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 References: <1525705912-12815-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1525705912-12815-11-git-send-email-akrowiak@linux.vnet.ibm.com> <53275110-45fb-d50f-c97e-93141378f094@linux.vnet.ibm.com> <89bda651-d465-af50-a737-1900a54b01c8@linux.ibm.com> <6f67a282-773d-3fca-5b36-cc23ad49ba5b@linux.vnet.ibm.com> From: Pierre Morel Date: Tue, 5 Jun 2018 14:40:44 +0200 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: <6f67a282-773d-3fca-5b36-cc23ad49ba5b@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 18060512-4275-0000-0000-0000028A5C02 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18060512-4276-0000-0000-00003791603C Message-Id: <32340d2a-bea6-bdb1-38a6-76afe3d54672@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-06-05_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=797 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1805220000 definitions=main-1806050147 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/05/2018 16:28, Tony Krowiak wrote: > On 05/24/2018 05:10 AM, Pierre Morel wrote: >> On 23/05/2018 16:38, Tony Krowiak wrote: >>> On 05/16/2018 03:55 AM, Pierre Morel wrote: >>>> On 07/05/2018 17:11, Tony Krowiak wrote: >>>>> Provides a sysfs interface to view the AP matrix configured for the >>>>> mediated matrix device. >>>>> >>>>> The relevant sysfs structures are: >>>>> >>>>> /sys/devices/vfio_ap >>>>> ... [matrix] >>>>> ...... [mdev_supported_types] >>>>> ......... [vfio_ap-passthrough] >>>>> ............ [devices] >>>>> ...............[$uuid] >>>>> .................. matrix >>>>> >>>>> To view the matrix configured for the mediated matrix device, >>>>> print the matrix file: >>>> >>>> This is the configured matrix, not the one used by the guest. >>>> Nothing in the patches protect against binding a queue and assigning >>>> a new AP when the guest runs. >>>> The card and queue will be showed by this entry. >>> >>> Of course, as stated above, this is the matrix configured for the >>> mediated matrix device. Are you suggesting here that the driver >>> should prevent assigning a new adapter or domain while a guest is >>> running? Couldn't this be a step in the process for hot (un)plugging >>> AP queues? >> >> No, I mean what is the point to show this? >> It is not what the guest sees. >> Has it any use case? > > The point is to display the matrix so one can view the AP queues that > have been assigned to the mediated matrix device. This is the only way > to view the matrix. Do you not find value in being able to see what > has been assigned to the mediated matrix device? Two things: 1) I think it is better to retrieve the individual masks 2) As I said above, what you show is not the effective mask used by the guest -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany