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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 C3F9FC43381 for ; Wed, 13 Mar 2019 10:15:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B5492087C for ; Wed, 13 Mar 2019 10:15:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726573AbfCMKP4 (ORCPT ); Wed, 13 Mar 2019 06:15:56 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:47258 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725992AbfCMKPz (ORCPT ); Wed, 13 Mar 2019 06:15:55 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x2DAFh8h113027 for ; Wed, 13 Mar 2019 06:15:55 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2r6x26wr04-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 13 Mar 2019 06:15:53 -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) Wed, 13 Mar 2019 10:15:23 -0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x2DAFL1d32047184 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 13 Mar 2019 10:15:22 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 913AD52073; Wed, 13 Mar 2019 10:15:21 +0000 (GMT) Received: from [9.152.224.140] (unknown [9.152.224.140]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 1FDA452071; Wed, 13 Mar 2019 10:15:21 +0000 (GMT) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v4 6/7] s390: ap: Cleanup on removing the AP device To: Tony Krowiak , borntraeger@de.ibm.com Cc: 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, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com References: <1550849400-27152-1-git-send-email-pmorel@linux.ibm.com> <1550849400-27152-7-git-send-email-pmorel@linux.ibm.com> <3956ad4c-55c9-e42c-4ab2-00ddae05b317@linux.ibm.com> <94904df0-42b6-51f8-6440-68722ef5419d@linux.ibm.com> From: Pierre Morel Date: Wed, 13 Mar 2019 11:15:20 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19031310-0016-0000-0000-0000026151EB X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19031310-0017-0000-0000-000032BBFDCB Message-Id: <85f772b4-0b62-701d-c3e5-e55e88c3fb4e@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-03-13_06:,, 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-1903130075 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/03/2019 22:53, Tony Krowiak wrote: > On 3/11/19 4:31 AM, Pierre Morel wrote: >> On 08/03/2019 23:43, Tony Krowiak wrote: >>> On 2/22/19 10:29 AM, Pierre Morel wrote: >>>> When the device is remove, we must make sure to >>>> clear the interruption and reset the AP device. >>>> >>>> We also need to clear the CRYCB of the guest. >>>> >>>> Signed-off-by: Pierre Morel >>>> --- >>>>   drivers/s390/crypto/vfio_ap_drv.c     | 35 >>>> +++++++++++++++++++++++++++++++++++ >>>>   drivers/s390/crypto/vfio_ap_ops.c     |  3 ++- >>>>   drivers/s390/crypto/vfio_ap_private.h |  3 +++ >>>>   3 files changed, 40 insertions(+), 1 deletion(-) >>>> ...snip... >>>> + * vfio_ap_update_crycb >>>> + * @q: A pointer to the queue being removed >>>> + * >>>> + * We clear the APID of the queue, making this queue unusable for >>>> the guest. >>>> + * After this function we can reset the queue without to fear a >>>> race with >>>> + * the guest to access the queue again. >>>> + * We do not fear race with the host as we still get the devic >>>> + */ >>>> +static void vfio_ap_update_crycb(struct vfio_ap_queue *q) >>>> +{ >>>> +    struct ap_matrix_mdev *matrix_mdev = q->matrix_mdev; >>>> + >>>> +    if (!matrix_mdev) >>>> +        return; >>>> + > > You should probably check whether the APID has been cleared before > proceeding. Take the case where an AP with multiple queues is removed > from the configuration via the SE or SCLP. The AP bus is going to invoke > the vfio_ap_queue_dev_remove() function for each of the queues. The APID > will get cleared on the first remove, so it is not only unnecessary to > clear it on subsequent removes, it is kind of nasty to keep resetting > the masks in the guest's CRYCB (below) each time the remove callback is > invoked. This can not happen. The only way to clear the APM is when the matrix is not associated with KVM. This case is tested and the masks are not changed. > >>>> +    clear_bit_inv(AP_QID_CARD(q->apqn), matrix_mdev->matrix.apm); >>>> + >>>> +    if (!matrix_mdev->kvm) >>>> +        return; >>>> + >>>> +    kvm_arch_crypto_set_masks(matrix_mdev->kvm, >>>> +                  matrix_mdev->matrix.apm, >>>> +                  matrix_mdev->matrix.aqm, >>>> +                  matrix_mdev->matrix.adm); >>>> +} -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany