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 7C9E1C43381 for ; Wed, 27 Feb 2019 09:58:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54C1E205F4 for ; Wed, 27 Feb 2019 09:58:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729818AbfB0J6a (ORCPT ); Wed, 27 Feb 2019 04:58:30 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:47778 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728036AbfB0J6a (ORCPT ); Wed, 27 Feb 2019 04:58:30 -0500 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1R9nM92004621 for ; Wed, 27 Feb 2019 04:58:29 -0500 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qwqe6txmh-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 27 Feb 2019 04:58:28 -0500 Received: from localhost by e06smtp02.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, 27 Feb 2019 09:58:24 -0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1R9wN1959965456 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 27 Feb 2019 09:58:23 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EA48DA4053; Wed, 27 Feb 2019 09:58:22 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 36566A4040; Wed, 27 Feb 2019 09:58:22 +0000 (GMT) Received: from [9.152.224.140] (unknown [9.152.224.140]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 27 Feb 2019 09:58:22 +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> <3f15bd09-8a90-ed8a-e15a-0f3bac1a3528@linux.ibm.com> From: Pierre Morel Date: Wed, 27 Feb 2019 10:58:22 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <3f15bd09-8a90-ed8a-e15a-0f3bac1a3528@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: 19022709-0008-0000-0000-000002C57F08 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19022709-0009-0000-0000-00002231CB9A Message-Id: <97bd632b-87a6-fa23-d4db-7ccdec877831@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-27_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 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-1902270066 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26/02/2019 19:27, 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(-) >> >> diff --git a/drivers/s390/crypto/vfio_ap_drv.c >> b/drivers/s390/crypto/vfio_ap_drv.c >> index eca0ffc..e5d91ff 100644 >> --- a/drivers/s390/crypto/vfio_ap_drv.c >> +++ b/drivers/s390/crypto/vfio_ap_drv.c >> @@ -5,6 +5,7 @@ >>    * Copyright IBM Corp. 2018 >>    * >>    * Author(s): Tony Krowiak >> + *          Pierre Morel >>    */ >>   #include >> @@ -12,6 +13,8 @@ >>   #include >>   #include >>   #include >> +#include >> +#include >>   #include "vfio_ap_private.h" >>   #define VFIO_AP_ROOT_NAME "vfio_ap" >> @@ -61,6 +64,33 @@ static int vfio_ap_queue_dev_probe(struct ap_device >> *apdev) >>   } >>   /** >> + * 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 device. >> + */ >> +static void vfio_ap_update_crycb(struct vfio_ap_queue *q) >> +{ >> +    struct ap_matrix_mdev *matrix_mdev = q->matrix_mdev; >> + >> +    if (!matrix_mdev) >> +        return; >> + >> +    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); >> +} >> + >> +/** >>    * vfio_ap_queue_dev_remove: >>    * >>    * Free the associated vfio_ap_queue structure >> @@ -70,6 +100,11 @@ static void vfio_ap_queue_dev_remove(struct >> ap_device *apdev) >>       struct vfio_ap_queue *q; >>       q = dev_get_drvdata(&apdev->device); >> +    if (!q) >> +        return; >> + >> +    vfio_ap_update_crycb(q); >> +    vfio_ap_mdev_reset_queue(q); > > The reset is unnecessary because once the card is removed from the > CRYCB, the ZAPQ may fail with because the queue may not exist anymore. The code here is run inside the host. So the queue is still available for ZAPQ. > Besides, once the card is removed from the guest's CRYCB, the bus > running in the guest will do a reset. I already answered this: - The AP bus reset the queue before calling the driver probe - which means that the guest can still access the queue after the reset done by the bus. - we need to first clear the CRYCB to remove the queue from the guest before we reset the queue. Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany