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 8EEFFC43381 for ; Tue, 19 Feb 2019 09:22:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6902C21848 for ; Tue, 19 Feb 2019 09:22:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728087AbfBSJWN (ORCPT ); Tue, 19 Feb 2019 04:22:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48586 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727736AbfBSJWM (ORCPT ); Tue, 19 Feb 2019 04:22:12 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AC17B9D43D; Tue, 19 Feb 2019 09:22:11 +0000 (UTC) Received: from gondolin (dhcp-192-187.str.redhat.com [10.33.192.187]) by smtp.corp.redhat.com (Postfix) with ESMTP id CDB45102495F; Tue, 19 Feb 2019 09:22:06 +0000 (UTC) Date: Tue, 19 Feb 2019 10:22:04 +0100 From: Cornelia Huck To: Pierre Morel Cc: borntraeger@de.ibm.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, akrowiak@linux.ibm.com, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com Subject: Re: [PATCH v2 1/1] s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem Message-ID: <20190219102204.5e050b76.cohuck@redhat.com> In-Reply-To: <1550513328-12646-2-git-send-email-pmorel@linux.ibm.com> References: <1550513328-12646-1-git-send-email-pmorel@linux.ibm.com> <1550513328-12646-2-git-send-email-pmorel@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 19 Feb 2019 09:22:11 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 18 Feb 2019 19:08:48 +0100 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 s/suppress/remove/ ? > 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(-) (...) > @@ -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; > +} > + > +static struct bus_type matrix_bus = { > + .name = "vfio_ap", > + .match = &matrix_bus_match, > +}; > + > +static int matrix_probe(struct device *dev) > +{ > + return 0; > +} I don't think you need this (the important function is the match function of the bus). > + > +static struct device_driver matrix_driver = { > + .name = "vfio_ap", > + .bus = &matrix_bus, > + .probe = matrix_probe, > +}; > + > static int vfio_ap_matrix_dev_create(void) > { > int ret; It's a bit annoying that we need to introduce a bus that basically does nothing, but I think this looks sane. Reviewed-by: Cornelia Huck