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 0859AC43219 for ; Tue, 30 Apr 2019 08:00:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF2B92075E for ; Tue, 30 Apr 2019 08:00:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726489AbfD3IAB (ORCPT ); Tue, 30 Apr 2019 04:00:01 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:54524 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726129AbfD3IAA (ORCPT ); Tue, 30 Apr 2019 04:00:00 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3U7rGWI090470 for ; Tue, 30 Apr 2019 03:59:59 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2s6hxvs64q-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 30 Apr 2019 03:59:59 -0400 Received: from localhost by e06smtp04.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) Tue, 30 Apr 2019 08:59:53 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x3U7xqGl43516056 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Apr 2019 07:59:52 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1B3275205A; Tue, 30 Apr 2019 07:59:52 +0000 (GMT) Received: from [9.152.222.31] (unknown [9.152.222.31]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 4E4415204E; Tue, 30 Apr 2019 07:59:51 +0000 (GMT) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v7 2/4] vfio: ap: register IOMMU VFIO notifier To: Halil Pasic Cc: borntraeger@de.ibm.com, alex.williamson@redhat.com, cohuck@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, akrowiak@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com References: <1556283688-556-1-git-send-email-pmorel@linux.ibm.com> <1556283688-556-3-git-send-email-pmorel@linux.ibm.com> <20190429180702.641c9110.pasic@linux.ibm.com> From: Pierre Morel Date: Tue, 30 Apr 2019 09:59:51 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190429180702.641c9110.pasic@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19043007-0016-0000-0000-00000276C390 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19043007-0017-0000-0000-000032D34CF0 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-30_03:,, 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=904 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904300054 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 29/04/2019 18:07, Halil Pasic wrote: > On Fri, 26 Apr 2019 15:01:26 +0200 > Pierre Morel wrote: > >> @@ -858,7 +887,17 @@ static int vfio_ap_mdev_open(struct mdev_device *mdev) >> return ret; >> } >> >> - return 0; >> + matrix_mdev->iommu_notifier.notifier_call = vfio_ap_mdev_iommu_notifier; >> + events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; >> + ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, >> + &events, &matrix_mdev->iommu_notifier); >> + if (!ret) >> + return ret; >> + >> + vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, >> + &matrix_mdev->group_notifier); >> + module_put(THIS_MODULE); > > Can you please explain this module_put() here? I don't see anything in > the cover letter. May be you should have a look at the sources or the original patch series of Tony, there is a try_module_get() at the beginning of open to make sure that the module is not taken away while in use by the guest. In the case we failed to open the mediated device we let fall the reference. Regards, Pierre > > Regards, > Halil > >> + return ret; >> } > -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany