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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 78BC1C352A2 for ; Fri, 7 Feb 2020 09:33:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 483AC20726 for ; Fri, 7 Feb 2020 09:33:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Z84OwjpK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726417AbgBGJdu (ORCPT ); Fri, 7 Feb 2020 04:33:50 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:20279 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726626AbgBGJdu (ORCPT ); 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Fri, 7 Feb 2020 09:33:41 +0000 (UTC) Received: from gondolin (ovpn-117-112.ams2.redhat.com [10.36.117.112]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3E3AC790F8; Fri, 7 Feb 2020 09:33:36 +0000 (UTC) Date: Fri, 7 Feb 2020 10:33:34 +0100 From: Cornelia Huck To: Alex Williamson Cc: kvm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, dev@dpdk.org, mtosatti@redhat.com, thomas@monjalon.net, bluca@debian.org, jerinjacobk@gmail.com, bruce.richardson@intel.com Subject: Re: [RFC PATCH 1/7] vfio: Include optional device match in vfio_device_ops callbacks Message-ID: <20200207103334.25b17267.cohuck@redhat.com> In-Reply-To: <20200206111842.705bf58a@w520.home> References: <158085337582.9445.17682266437583505502.stgit@gimli.home> <158085754299.9445.4389176548645142886.stgit@gimli.home> <20200206121419.69997326.cohuck@redhat.com> <20200206111842.705bf58a@w520.home> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Thu, 6 Feb 2020 11:18:42 -0700 Alex Williamson wrote: > On Thu, 6 Feb 2020 12:14:19 +0100 > Cornelia Huck wrote: > > > On Tue, 04 Feb 2020 16:05:43 -0700 > > Alex Williamson wrote: > > > > > Allow bus drivers to provide their own callback to match a device to > > > the user provided string. > > > > > > Signed-off-by: Alex Williamson > > > --- > > > drivers/vfio/vfio.c | 19 +++++++++++++++---- > > > include/linux/vfio.h | 3 +++ > I think with your first option we arrive at something like this: > > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c > index dda1726adda8..b5609a411139 100644 > --- a/drivers/vfio/vfio.c > +++ b/drivers/vfio/vfio.c > @@ -883,14 +883,15 @@ static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group, > > if (it->ops->match) { > ret = it->ops->match(it->device_data, buf); > - if (ret < 0 && ret != -ENODEV) { > + if (ret < 0) { > device = ERR_PTR(ret); > break; > } > - } else > - ret = strcmp(dev_name(it->dev), buf); > + } else { > + ret = !strcmp(dev_name(it->dev), buf); > + } > > - if (!ret) { > + if (ret) { > device = it; > vfio_device_get(device); > break; > diff --git a/include/linux/vfio.h b/include/linux/vfio.h > index 755e0f0e2900..029694b977f2 100644 > --- a/include/linux/vfio.h > +++ b/include/linux/vfio.h > @@ -26,8 +26,9 @@ > * operations documented below > * @mmap: Perform mmap(2) on a region of the device file descriptor > * @request: Request for the bus driver to release the device > - * @match: Optional device name match callback (return: 0 for match, -ENODEV > - * (or >0) for no match and continue, other -errno: no match and stop) > + * @match: Optional device name match callback (return: 0 for no-match, >0 for > + * match, -errno for abort (ex. match with insufficient or incorrect > + * additional args) > */ > struct vfio_device_ops { > char *name; > > > I like that. Thanks, > > Alex Looks good to me.