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 A21C8C43381 for ; Tue, 19 Feb 2019 21:31:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F0462147C for ; Tue, 19 Feb 2019 21:31:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729714AbfBSVb0 (ORCPT ); Tue, 19 Feb 2019 16:31:26 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48090 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729140AbfBSVb0 (ORCPT ); Tue, 19 Feb 2019 16:31:26 -0500 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 x1JLIu6Z134455 for ; Tue, 19 Feb 2019 16:31:24 -0500 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0b-001b2d01.pphosted.com with ESMTP id 2qrs7m1am9-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 19 Feb 2019 16:31:23 -0500 Received: from localhost by e06smtp07.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) Tue, 19 Feb 2019 21:31:19 -0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1JLVIgY24051938 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 19 Feb 2019 21:31:18 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 079F3A405B; Tue, 19 Feb 2019 21:31:18 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 88284A405F; Tue, 19 Feb 2019 21:31:17 +0000 (GMT) Received: from [9.145.76.69] (unknown [9.145.76.69]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 19 Feb 2019 21:31:17 +0000 (GMT) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v2 1/1] s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem To: Tony Krowiak , 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> <8e6853ba-12ed-a4f3-1263-0e15f715b644@linux.ibm.com> From: Pierre Morel Date: Tue, 19 Feb 2019 22:31:17 +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: <8e6853ba-12ed-a4f3-1263-0e15f715b644@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: 19021921-0028-0000-0000-0000034A897E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19021921-0029-0000-0000-00002408C6C2 Message-Id: <6cc5b478-4678-9a82-b902-cc9aed22becf@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-19_14:,, 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-1902190149 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/02/2019 19:52, Tony Krowiak wrote: > 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. I think Conny already answered this question. > >> +} >> + >> +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. I would like too, but changing this will change the path to the mediated device supported type. > >> +    .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. > OTOH bind/unbind has no impact. If no one else ask for this I will not change what has already been reviewed by Conny and Christian. Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany