From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753114AbeDPOvr (ORCPT ); Mon, 16 Apr 2018 10:51:47 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:36698 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751182AbeDPOvo (ORCPT ); Mon, 16 Apr 2018 10:51:44 -0400 Subject: Re: [PATCH v4 13/15] KVM: s390: configure the guest's AP devices To: Pierre Morel , 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, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com References: <1523827345-11600-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1523827345-11600-14-git-send-email-akrowiak@linux.vnet.ibm.com> <2e7387b9-ceb4-cdca-56ac-f5344084e10a@linux.vnet.ibm.com> From: Halil Pasic Date: Mon, 16 Apr 2018 16:51:31 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <2e7387b9-ceb4-cdca-56ac-f5344084e10a@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 18041614-0040-0000-0000-0000042F9383 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18041614-0041-0000-0000-0000263398CB Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-04-16_08:,, 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 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1804160139 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/16/2018 03:05 PM, Pierre Morel wrote: >> +static void vfio_ap_mdev_release(struct mdev_device *mdev) >> +{ >> +    struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); >> + >> +    kvm_ap_deconfigure_matrix(matrix_mdev->kvm); >> +    kvm_ap_interpret_instructions(matrix_mdev->kvm, false); > > This call clears the apie in KVM. > This is only OK if we have a single device present until the end of the VM, > otherwise AP instructions in the guest will fail after the release until the end of the VM > or until a new device is plugged. I agree, this seems wrong.