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=-6.9 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 66155C04A6B for ; Mon, 6 May 2019 10:55:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D31F2082F for ; Mon, 6 May 2019 10:55:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726424AbfEFKz6 (ORCPT ); Mon, 6 May 2019 06:55:58 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:56148 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725853AbfEFKz5 (ORCPT ); Mon, 6 May 2019 06:55:57 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x46Ar7V1098491 for ; Mon, 6 May 2019 06:55:55 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0b-001b2d01.pphosted.com with ESMTP id 2sakgx05hg-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 06 May 2019 06:55:55 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 6 May 2019 11:55:53 +0100 Received: from b06cxnps3075.portsmouth.uk.ibm.com (9.149.109.195) by e06smtp07.uk.ibm.com (192.168.101.137) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 6 May 2019 11:55:52 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x46Atorg40173808 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 6 May 2019 10:55:50 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 78C3852052; Mon, 6 May 2019 10:55:50 +0000 (GMT) Received: from [9.145.46.119] (unknown [9.145.46.119]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id BCF415204E; Mon, 6 May 2019 10:55:49 +0000 (GMT) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v2 6/7] s390: vfio-ap: handle bind and unbind of AP queue device To: Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: freude@linux.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, frankja@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, pasic@linux.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com References: <1556918073-13171-1-git-send-email-akrowiak@linux.ibm.com> <1556918073-13171-7-git-send-email-akrowiak@linux.ibm.com> From: Pierre Morel Date: Mon, 6 May 2019 12:55:49 +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: <1556918073-13171-7-git-send-email-akrowiak@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: 19050610-0028-0000-0000-0000036ACAA2 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19050610-0029-0000-0000-0000242A3EF6 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-06_07:,, 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-1905060096 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/05/2019 23:14, Tony Krowiak wrote: > There is nothing preventing a root user from inadvertently unbinding an > AP queue device that is in use by a guest from the vfio_ap device driver > and binding it to a zcrypt driver. This can result in a queue being > accessible from both the host and a guest. > > This patch introduces safeguards that prevent sharing of an AP queue > between the host when a queue device is unbound from the vfio_ap device > driver. In addition, this patch restores guest access to AP queue devices > bound to the vfio_ap driver if the queue's APQN is assigned to an mdev > device in use by a guest. > > Signed-off-by: Tony Krowiak > --- > drivers/s390/crypto/vfio_ap_drv.c | 12 +++- > drivers/s390/crypto/vfio_ap_ops.c | 100 +++++++++++++++++++++++++++++++++- > drivers/s390/crypto/vfio_ap_private.h | 2 + > 3 files changed, 111 insertions(+), 3 deletions(-) > > diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c > index e9824c35c34f..c215978daf39 100644 > --- a/drivers/s390/crypto/vfio_ap_drv.c > +++ b/drivers/s390/crypto/vfio_ap_drv.c > @@ -42,12 +42,22 @@ MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids); > > static int vfio_ap_queue_dev_probe(struct ap_device *apdev) > { > + struct ap_queue *queue = to_ap_queue(&apdev->device); > + > + mutex_lock(&matrix_dev->lock); > + vfio_ap_mdev_probe_queue(queue); > + mutex_unlock(&matrix_dev->lock); > + > return 0; > } > > static void vfio_ap_queue_dev_remove(struct ap_device *apdev) > { > - /* Nothing to do yet */ > + struct ap_queue *queue = to_ap_queue(&apdev->device); > + > + mutex_lock(&matrix_dev->lock); > + vfio_ap_mdev_remove_queue(queue); > + mutex_unlock(&matrix_dev->lock); > } > > static void vfio_ap_matrix_dev_release(struct device *dev) > diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c > index ede45184eb67..40324951bd37 100644 > --- a/drivers/s390/crypto/vfio_ap_ops.c > +++ b/drivers/s390/crypto/vfio_ap_ops.c > @@ -226,8 +226,6 @@ static struct device *vfio_ap_get_queue_dev(unsigned long apid, > &apqn, match_apqn); > } > > - > - > static int vfio_ap_mdev_validate_masks(unsigned long *apm, unsigned long *aqm) > { > int ret; > @@ -259,6 +257,27 @@ static bool vfio_ap_queues_on_drv(unsigned long *apm, unsigned long *aqm) > return true; > } > > +static bool vfio_ap_card_on_drv(struct ap_queue *queue, unsigned long *aqm) > +{ > + unsigned long apid, apqi; > + struct device *dev; > + > + apid = AP_QID_CARD(queue->qid); > + > + for_each_set_bit_inv(apqi, aqm, AP_DOMAINS) { > + if (queue->qid == AP_MKQID(apid, apqi)) > + continue; > + > + dev = vfio_ap_get_queue_dev(apid, apqi); > + if (!dev) > + return false; > + > + put_device(dev); > + } > + > + return true; > +} > + > /** > * assign_adapter_store > * > @@ -1017,3 +1036,80 @@ void vfio_ap_mdev_unregister(void) > { > mdev_unregister_device(&matrix_dev->device); > } > + > +static struct ap_matrix_mdev *vfio_ap_mdev_find_matrix_mdev(unsigned long apid, > + unsigned long apqi) > +{ > + struct ap_matrix_mdev *matrix_mdev; > + > + list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) { > + if (test_bit_inv(apid, matrix_mdev->matrix.apm) && > + test_bit_inv(apqi, matrix_mdev->matrix.aqm)) > + return matrix_mdev; > + } > + > + return NULL; > +} > + > +void vfio_ap_mdev_probe_queue(struct ap_queue *queue) > +{ > + struct ap_matrix_mdev *matrix_mdev; > + unsigned long *shadow_apm, *shadow_aqm; > + unsigned long apid = AP_QID_CARD(queue->qid); > + unsigned long apqi = AP_QID_QUEUE(queue->qid); > + > + /* > + * Find the mdev device to which the APQN of the queue device being > + * probed is assigned > + */ > + matrix_mdev = vfio_ap_mdev_find_matrix_mdev(apid, apqi); > + > + /* Check whether we found an mdev device and it is in use by a guest */ > + if (matrix_mdev && matrix_mdev->kvm) { > + shadow_apm = matrix_mdev->shadow_crycb->apm; > + shadow_aqm = matrix_mdev->shadow_crycb->aqm; > + /* > + * If the guest already has access to the adapter card > + * referenced by APID or does not have access to the queues > + * referenced by APQI, there is nothing to do here. > + */ > + if (test_bit_inv(apid, shadow_apm) || > + !test_bit_inv(apqi, shadow_aqm)) > + return; > + > + /* > + * If each APQN with the APID of the queue being probed and an > + * APQI in the shadow CRYCB references a queue device that is > + * bound to the vfio_ap driver, then plug the adapter into the > + * guest. > + */ > + if (vfio_ap_card_on_drv(queue, shadow_aqm)) { > + set_bit_inv(apid, shadow_apm); > + vfio_ap_mdev_update_crycb(matrix_mdev); > + } > + } > +} > + > +void vfio_ap_mdev_remove_queue(struct ap_queue *queue) > +{ > + struct ap_matrix_mdev *matrix_mdev; > + unsigned long apid = AP_QID_CARD(queue->qid); > + unsigned long apqi = AP_QID_QUEUE(queue->qid); > + > + matrix_mdev = vfio_ap_mdev_find_matrix_mdev(apid, apqi); > + > + /* > + * If the queue is assigned to the mdev device and the mdev device > + * is in use by a guest, unplug the adapter referred to by the APID > + * of the APQN of the queue being removed. > + */ > + if (matrix_mdev && matrix_mdev->kvm) { > + if (!test_bit_inv(apid, matrix_mdev->shadow_crycb->apm)) > + return; > + > + clear_bit_inv(apid, matrix_mdev->shadow_crycb->apm); > + vfio_ap_mdev_update_crycb(matrix_mdev); > + } > + > + vfio_ap_mdev_reset_queue(apid, apqi); > +} > diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h > index e8457aa61976..6b1f7df5b979 100644 > --- a/drivers/s390/crypto/vfio_ap_private.h > +++ b/drivers/s390/crypto/vfio_ap_private.h > @@ -87,5 +87,7 @@ struct ap_matrix_mdev { > > extern int vfio_ap_mdev_register(void); > extern void vfio_ap_mdev_unregister(void); > +void vfio_ap_mdev_remove_queue(struct ap_queue *queue); > +void vfio_ap_mdev_probe_queue(struct ap_queue *queue); > > #endif /* _VFIO_AP_PRIVATE_H_ */ > AFAIU the apmask/aqmask of the AP_BUS are replacing bind/unbind for the admin. Don't they? Then why not suppress bind/unbind for ap_queues? Otherwise, it seems to me to handle correctly the disappearance of a card, which is the only thing that can happen from out of the firmware queue change requires configuration change and re-IPL. Even still need testing, LGTM -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany