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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 343AFC43381 for ; Tue, 19 Feb 2019 21:34:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 017032147C for ; Tue, 19 Feb 2019 21:34:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729470AbfBSVeO (ORCPT ); Tue, 19 Feb 2019 16:34:14 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36706 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727206AbfBSVeO (ORCPT ); Tue, 19 Feb 2019 16:34:14 -0500 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1JLYAIA152828 for ; Tue, 19 Feb 2019 16:34:12 -0500 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0b-001b2d01.pphosted.com with ESMTP id 2qrs761fhe-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 19 Feb 2019 16:34:08 -0500 Received: from localhost by e11.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) Tue, 19 Feb 2019 21:34:04 -0000 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1JLY0R123330996 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 19 Feb 2019 21:34:00 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 372D2AE05F; Tue, 19 Feb 2019 21:34:00 +0000 (GMT) Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DA980AE05C; Tue, 19 Feb 2019 21:33:59 +0000 (GMT) Received: from [9.60.75.235] (unknown [9.60.75.235]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP; Tue, 19 Feb 2019 21:33:59 +0000 (GMT) Subject: Re: [PATCH v3 6/9] vfio: ap: register IOMMU VFIO notifier To: Halil Pasic Cc: Pierre Morel , 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, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com References: <1550152269-6317-1-git-send-email-pmorel@linux.ibm.com> <1550152269-6317-7-git-send-email-pmorel@linux.ibm.com> <3ce0a3a0-22fb-c418-321d-7e6e3af5b66c@linux.ibm.com> <20190219105946.29e510a6@oc2783563651> From: Tony Krowiak Date: Tue, 19 Feb 2019 16:33:59 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20190219105946.29e510a6@oc2783563651> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19021921-2213-0000-0000-000003547517 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010628; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000281; SDB=6.01163473; UDB=6.00607498; IPR=6.00944055; MB=3.00025661; MTD=3.00000008; XFM=3.00000015; UTC=2019-02-19 21:34:05 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19021921-2214-0000-0000-00005D68F5C6 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-19_14:,, 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=8.0.1-1810050000 definitions=main-1902190150 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/19/19 4:59 AM, Halil Pasic wrote: > On Fri, 15 Feb 2019 17:55:35 -0500 > Tony Krowiak wrote: > >> On 2/14/19 8:51 AM, Pierre Morel wrote: >>> To be able to use the VFIO interface to facilitate the >>> mediated device memory pining/unpining we need to register >>> a notifier for IOMMU. >>> >>> Signed-off-by: Pierre Morel >>> --- >>> drivers/s390/crypto/vfio_ap_ops.c | 64 +++++++++++++++++++++++++++++++---- >>> drivers/s390/crypto/vfio_ap_private.h | 2 ++ >>> 2 files changed, 60 insertions(+), 6 deletions(-) >>> >>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c >>> index 1851b24..6eddc2c 100644 >>> --- a/drivers/s390/crypto/vfio_ap_ops.c >>> +++ b/drivers/s390/crypto/vfio_ap_ops.c > > [..] > struct vfio_ap_queue *q; >>> @@ -967,12 +996,32 @@ static int vfio_ap_mdev_open(struct mdev_device *mdev) >>> >>> ret = vfio_register_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, >>> &events, &matrix_mdev->group_notifier); >>> - if (ret) { >>> - module_put(THIS_MODULE); >>> - return ret; >>> - } >>> + if (ret) >>> + goto err_group; >>> + >>> + 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) >>> + goto err_iommu; >>> + >>> + ret = vfio_ap_associate_queues(matrix_mdev); >>> + if (ret) >>> + goto err_associate; >> >> I think the matrix_mdev should be associated with queues when an >> assignment of an adapter or domain is made to the mdev device via its >> sysfs interfaces. I say this because assigning an adapter or domain to >> an mdev device effectively grants ownership of any additional AP queues >> added to the mdev device's AP matrix as a result of the assignment. It >> only makes sense to assign ownership to the vfio_ap_queue objects >> representing the queues at that time. If an adapter or domain is >> dynamically assigned while a guest is using the affected queues, then >> the associations will have to be made at that time and this code will >> likely go bye bye. >> > > > Actually, we need the stuff in vfio_ap_queues only if the guest is > offered to decides to use AP adaper interrupts. I would prefer to have > it around only when needed: as long as we have the nib pinned for any > given queue. Is there a reason why not to do so? Even if we keep the vfio_ap_queue around for the life of a guest, association/dissociation will have to be done when an adapter or domain is dynamically assigned. > > Regards, > Halil > > [..] >