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 579D8C43381 for ; Tue, 19 Feb 2019 18:53:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 15D5A21738 for ; Tue, 19 Feb 2019 18:53:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728782AbfBSSw6 (ORCPT ); Tue, 19 Feb 2019 13:52:58 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:53182 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725875AbfBSSw6 (ORCPT ); Tue, 19 Feb 2019 13:52:58 -0500 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1JImmp6017477 for ; Tue, 19 Feb 2019 13:52:56 -0500 Received: from e16.ny.us.ibm.com (e16.ny.us.ibm.com [129.33.205.206]) by mx0b-001b2d01.pphosted.com with ESMTP id 2qrpqd27gw-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 19 Feb 2019 13:52:55 -0500 Received: from localhost by e16.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 18:52:52 -0000 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1JIqnMN23527600 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 19 Feb 2019 18:52:49 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F0D55AE062; Tue, 19 Feb 2019 18:52:48 +0000 (GMT) Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B21C6AE05C; Tue, 19 Feb 2019 18:52:48 +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 18:52:48 +0000 (GMT) Subject: Re: [PATCH v2 1/1] s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem To: Pierre Morel , borntraeger@de.ibm.com Cc: cohuck@redhat.com, linux-kernel@vger.kernel.org, linux-s390@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 References: <1550513328-12646-1-git-send-email-pmorel@linux.ibm.com> <1550513328-12646-2-git-send-email-pmorel@linux.ibm.com> From: Tony Krowiak Date: Tue, 19 Feb 2019 13:52:48 -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: <1550513328-12646-2-git-send-email-pmorel@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19021918-0072-0000-0000-000003FC44B4 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010627; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000281; SDB=6.01163419; UDB=6.00607465; IPR=6.00944001; MB=3.00025659; MTD=3.00000008; XFM=3.00000015; UTC=2019-02-19 18:52:54 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19021918-0073-0000-0000-00004B3B9B30 Message-Id: <8e6853ba-12ed-a4f3-1263-0e15f715b644@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-19_12:,, 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-1902190134 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/18/19 1:08 PM, Pierre Morel wrote: > Libudev relies on having a subsystem link for non-root devices. To > avoid libudev (and potentially other userspace tools) choking on the > matrix device let us introduce a vfio_ap bus and with that the vfio_ap > bus subsytem, and make the matrix device reside within it. > > Doing this we need to suppress the forced link from the matrix device to > the vfio_ap driver and we suppress the device_type we do not need > anymore. > > Since the associated matrix driver is not the vfio_ap driver any more, > we have to change the search for the devices on the vfio_ap driver in > the function vfio_ap_verify_queue_reserved. > > Reported-by: Marc Hartmayer > Reported-by: Christian Borntraeger > Signed-off-by: Pierre Morel > --- > drivers/s390/crypto/vfio_ap_drv.c | 48 +++++++++++++++++++++++++++++------ > drivers/s390/crypto/vfio_ap_ops.c | 4 +-- > drivers/s390/crypto/vfio_ap_private.h | 1 + > 3 files changed, 43 insertions(+), 10 deletions(-) > > diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c > index 31c6c84..8e45559 100644 > --- a/drivers/s390/crypto/vfio_ap_drv.c > +++ b/drivers/s390/crypto/vfio_ap_drv.c > @@ -24,10 +24,6 @@ MODULE_LICENSE("GPL v2"); > > static struct ap_driver vfio_ap_drv; > > -static struct device_type vfio_ap_dev_type = { > - .name = VFIO_AP_DEV_TYPE_NAME, > -}; > - > struct ap_matrix_dev *matrix_dev; > > /* Only type 10 adapters (CEX4 and later) are supported > @@ -62,6 +58,27 @@ static void vfio_ap_matrix_dev_release(struct device *dev) > kfree(matrix_dev); > } > > +static int matrix_bus_match(struct device *dev, struct device_driver *drv) > +{ > + return 1; I think we should verify the following: * dev == matrix_dev->device * drv == &matrix_driver The model employed is for the matrix device to be a singleton, so I think we should verify that the matrix device and driver defined herein ought to be the only possible choices for a match. Of course, doing so will require some restructuring of this patch. > +} > + > +static struct bus_type matrix_bus = { > + .name = "vfio_ap", > + .match = &matrix_bus_match, > +}; > + > +static int matrix_probe(struct device *dev) > +{ > + return 0; > +} > + > +static struct device_driver matrix_driver = { > + .name = "vfio_ap", This is the same name used for the original device driver. I think this driver ought to have a different name to avoid confusion. How about vfio_ap_matrix or some other name to differentiate the two. > + .bus = &matrix_bus, > + .probe = matrix_probe, I would add: .suppress_bind_attrs = true; This will remove the sysfs bind/unbind interfaces. Since there is only one matrix device and it's lifecycle is controlled herein, there is no sense in allowing a root user to bind/unbind it. > +}; > + > static int vfio_ap_matrix_dev_create(void) > { > int ret; > @@ -71,6 +88,10 @@ static int vfio_ap_matrix_dev_create(void) > if (IS_ERR(root_device)) > return PTR_ERR(root_device); > > + ret = bus_register(&matrix_bus); > + if (ret) > + goto bus_register_err; > + > matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL); > if (!matrix_dev) { > ret = -ENOMEM; > @@ -87,30 +108,41 @@ static int vfio_ap_matrix_dev_create(void) > mutex_init(&matrix_dev->lock); > INIT_LIST_HEAD(&matrix_dev->mdev_list); > > - matrix_dev->device.type = &vfio_ap_dev_type; > dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME); > matrix_dev->device.parent = root_device; > + matrix_dev->device.bus = &matrix_bus; > matrix_dev->device.release = vfio_ap_matrix_dev_release; > - matrix_dev->device.driver = &vfio_ap_drv.driver; > + matrix_dev->vfio_ap_drv = &vfio_ap_drv; > > ret = device_register(&matrix_dev->device); > if (ret) > goto matrix_reg_err; > > + ret = driver_register(&matrix_driver); > + if (ret) > + goto matrix_drv_err; > + > return 0; > > +matrix_drv_err: > + device_unregister(&matrix_dev->device); > matrix_reg_err: > put_device(&matrix_dev->device); > matrix_alloc_err: > + bus_unregister(&matrix_bus); > +bus_register_err: > root_device_unregister(root_device); > - > return ret; > } > > static void vfio_ap_matrix_dev_destroy(void) > { > + struct device *root_device = matrix_dev->device.parent; > + > + driver_unregister(&matrix_driver); > device_unregister(&matrix_dev->device); > - root_device_unregister(matrix_dev->device.parent); > + bus_unregister(&matrix_bus); > + root_device_unregister(root_device); > } > > static int __init vfio_ap_init(void) > diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c > index 272ef42..900b9cf 100644 > --- a/drivers/s390/crypto/vfio_ap_ops.c > +++ b/drivers/s390/crypto/vfio_ap_ops.c > @@ -198,8 +198,8 @@ static int vfio_ap_verify_queue_reserved(unsigned long *apid, > qres.apqi = apqi; > qres.reserved = false; > > - ret = driver_for_each_device(matrix_dev->device.driver, NULL, &qres, > - vfio_ap_has_queue); > + ret = driver_for_each_device(&matrix_dev->vfio_ap_drv->driver, NULL, > + &qres, vfio_ap_has_queue); > if (ret) > return ret; > > diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h > index 5675492..76b7f98 100644 > --- a/drivers/s390/crypto/vfio_ap_private.h > +++ b/drivers/s390/crypto/vfio_ap_private.h > @@ -40,6 +40,7 @@ struct ap_matrix_dev { > struct ap_config_info info; > struct list_head mdev_list; > struct mutex lock; > + struct ap_driver *vfio_ap_drv; > }; > > extern struct ap_matrix_dev *matrix_dev; >