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 58F49C4646D for ; Fri, 10 Aug 2018 16:25:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 11A782189B for ; Fri, 10 Aug 2018 16:25:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11A782189B 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 S1729305AbeHJSza (ORCPT ); Fri, 10 Aug 2018 14:55:30 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:41202 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728997AbeHJSz3 (ORCPT ); Fri, 10 Aug 2018 14:55:29 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7AGOo2S104993 for ; Fri, 10 Aug 2018 12:24:57 -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 2ksayjrpdk-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 10 Aug 2018 12:24:56 -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) Fri, 10 Aug 2018 12:24:52 -0400 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w7AGOoPH19202462 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 10 Aug 2018 16:24:50 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4FB4FAC059; Fri, 10 Aug 2018 12:25:17 -0400 (EDT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5F164AC060; Fri, 10 Aug 2018 12:25:15 -0400 (EDT) Received: from oc8043147753.ibm.com (unknown [9.80.230.146]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP; Fri, 10 Aug 2018 12:25:15 -0400 (EDT) Subject: Re: [PATCH v8 17/22] s390: vfio-ap: zeroize the AP queues. To: Cornelia Huck , Pierre Morel Cc: 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, borntraeger@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: <1533739472-7172-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1533739472-7172-18-git-send-email-akrowiak@linux.vnet.ibm.com> <20180810111445.015fcf2a.cohuck@redhat.com> <20180810131648.4fab1d7a.cohuck@redhat.com> From: Tony Krowiak Date: Fri, 10 Aug 2018 12:24:47 -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: <20180810131648.4fab1d7a.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: 18081016-0068-0000-0000-00000326D4D7 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009518; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01071704; UDB=6.00551954; IPR=6.00851495; MB=3.00022637; MTD=3.00000008; XFM=3.00000015; UTC=2018-08-10 16:24:54 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18081016-0069-0000-0000-000045587C4F Message-Id: <14983b58-f53b-8bd9-179e-29b9a69c21d8@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-10_10:,, 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-1808100177 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/10/2018 07:16 AM, Cornelia Huck wrote: > On Fri, 10 Aug 2018 12:49:08 +0200 > Pierre Morel wrote: > >> On 10/08/2018 11:14, Cornelia Huck wrote: >>> On Wed, 8 Aug 2018 10:44:27 -0400 >>> Tony Krowiak wrote: >>> >>>> From: Tony Krowiak >>>> >>>> Let's call PAPQ(ZAPQ) to zeroize a queue: >>>> >>>> * For each queue configured for a mediated matrix device >>>> when it is released. >>>> >>>> Zeroizing a queue resets the queue, clears all pending >>>> messages for the queue entries and disables adapter interruptions >>>> associated with the queue. >>>> >>>> Signed-off-by: Tony Krowiak >>>> Reviewed-by: Halil Pasic >>>> Tested-by: Michael Mueller >>>> Tested-by: Farhan Ali >>>> Signed-off-by: Christian Borntraeger >>>> --- >>>> drivers/s390/crypto/vfio_ap_ops.c | 29 ++++++++++++++++++++++++++++- >>>> drivers/s390/crypto/vfio_ap_private.h | 25 +++++++++++++++++++++++++ >>>> 2 files changed, 53 insertions(+), 1 deletions(-) >>>> >>>> @@ -788,7 +812,10 @@ static void vfio_ap_mdev_release(struct mdev_device *mdev) >>>> { >>>> struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); >>>> >>>> - kvm_arch_crypto_clear_masks(matrix_mdev->kvm); >>>> + if (matrix_mdev->kvm) >>>> + kvm_arch_crypto_clear_masks(matrix_mdev->kvm); >>> Confused. Why is the check for matrix_mdev->kvm added here? >> When using the KVM notifier we can get two notifications: >> -> KVM is here / is comming >> -> KVM is not here / disappearing >> >> In the first case we initialize matrix_mdev->kvm with a pointer to KVM >> In the second case we nullify the pointer. >> >> During the open of the mediated device, the guest should have been started >> or we refuse to start. >> >> During the close of the mediated device, the guest should be there, but >> we have no certitude that the guest did not disappear before the VFIO >> file being closed. >> Since we do not allow multiple guests using the same mediated device >> this case should not happen with QEMU. But I am not sure that >> a rogue user program could not stop KVM before closing the VFIO >> mediated device. > I'm not sure why the check is introduced in this patch, though. But > maybe I just need weekend :) Good catch, it belongs in patch 15 where the function is introduced. Is that the only reason for your objection? > >> Maybe Alex can confirm this point, if not we can remove the test.