Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757356Ab3J1SLU (ORCPT ); Mon, 28 Oct 2013 14:11:20 -0400 Received: from [207.46.163.28] ([207.46.163.28]:55093 "EHLO co9outboundpool.messaging.microsoft.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756672Ab3J1SLT (ORCPT ); Mon, 28 Oct 2013 14:11:19 -0400 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: -4 X-BigFish: VS-4(zz98dI936eI1432I4015Izz1f42h208ch1ee6h1de0h1fdah2073h1202h1e76h1d1ah1d2ah1fc6hzzz2dh2a8h839h93fhd24hf0ah1288h12a5h12a9h12bdh137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1ad9h1b0ah1b2fh1fb3h1d0ch1d2eh1d3fh1dfeh1dffh1e23h1fe8h1ff5h1155h) Message-ID: <1382983792.3410.13.camel@snotra.buserror.net> Subject: Re: [PATCH 3/4] VFIO: pci: amend vfio-pci for explicit binding via sysfs only From: Scott Wood To: Alex Williamson CC: Kim Phillips , Bhushan Bharat , Wood Scott , Yoder Stuart , , , , , Sethi Varun , , , , Date: Mon, 28 Oct 2013 13:09:52 -0500 In-Reply-To: <1382983205.3410.6.camel@snotra.buserror.net> References: <1381418830.7979.405.camel@snotra.buserror.net> <1381472840-3470-1-git-send-email-kim.phillips@linaro.org> <1381472840-3470-3-git-send-email-kim.phillips@linaro.org> <1382982462.4097.38.camel@ul30vt.home> <1382983205.3410.6.camel@snotra.buserror.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4-0ubuntu1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-OriginatorOrg: freescale.com X-FOPE-CONNECTOR: Id%0$Dn%*$RO%0$TLS%0$FQDN%$TlsDn% Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1308 Lines: 30 On Mon, 2013-10-28 at 13:00 -0500, Scott Wood wrote: > On Mon, 2013-10-28 at 11:47 -0600, Alex Williamson wrote: > > On Fri, 2013-10-11 at 01:27 -0500, Kim Phillips wrote: > > > Force the vfio-pci driver to only be bound explicitly via sysfs to avoid > > > conflics with other drivers in the event of a hotplug. > > > > We can't break userspace, so we can't disable the current method of > > binding devices to vfio-pci. We can add a new method and perhaps > > deprecate the existing mechanism to be removed at some point in the > > future. Thanks, > > I thought the existing method involved using sysfs bind, and this was > just eliminating a race. How does the bind get triggered currently? OK, so it seems it's relying on the write to new_id calling driver_attach(). Sigh. I guess we could make driver-sysfs-bind-only be settable via sysfs, and have new-userspace set both that and PCI_ANY_ID (or the specific ID if userspace prefers) via new_id. The platform bus patches could continue as is, since there's no existing mechanism to break. -Scott -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/