Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992643AbXEBC4m (ORCPT ); Tue, 1 May 2007 22:56:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992644AbXEBC4m (ORCPT ); Tue, 1 May 2007 22:56:42 -0400 Received: from outbound-mail-53.bluehost.com ([69.89.20.33]:43917 "HELO outbound-mail-53.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S2992643AbXEBC4l (ORCPT ); Tue, 1 May 2007 22:56:41 -0400 From: Jesse Barnes To: Olivier Galibert Subject: Re: [RFC PATCH] PCI MMCONFIG: add validation against ACPI motherboard resources Date: Tue, 1 May 2007 19:56:29 -0700 User-Agent: KMail/1.9.6 Cc: Robert Hancock , linux-kernel , Andi Kleen , Chuck Ebbert , Len Brown References: <4635510D.4060103@shaw.ca> <20070430225916.GA39223@dspnet.fr.eu.org> <200705011941.07438.jbarnes@virtuousgeek.org> In-Reply-To: <200705011941.07438.jbarnes@virtuousgeek.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200705011956.30629.jbarnes@virtuousgeek.org> X-Identified-User: {642:box128.bluehost.com:virtuous:virtuousgeek.org} {sentby:smtp auth 67.161.73.10 authed with jbarnes@virtuousgeek.org} Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2079 Lines: 41 On Tuesday, May 01, 2007, Jesse Barnes wrote: > On Monday, April 30, 2007, Olivier Galibert wrote: > > On Sun, Apr 29, 2007 at 08:14:37PM -0600, Robert Hancock wrote: > > > -Validate that the area is reserved even if we read it from the > > > chipset directly and not from the MCFG table. This catches the case > > > where the BIOS didn't set the location properly in the chipset and > > > has mapped it over other things it shouldn't have. This might be > > > overly pessimistic - we might be able to instead verify that no > > > other reserved resources (like chipset registers) are inside this > > > memory range. > > > > I have a fundamental problem with that: you don't validate a higher > > reliability information against a lower one. The chipset registers > > are high reliability. Modulo unknown hardware erratas and bugs in the > > code (and accepting f0000000 is in practice a bug in the code, the > > docs are starting to catch up with it too), the chipset *will* decode > > mmconfig at the looked up address no matter what. On the other side, > > the ACPI data is bios generated, and that is well known to be horribly > > unreliable. Hell, if it was reliable we could just use the MFCG ACPI > > table without questions. > > Now that I've read his patch closely I think you're right. > > Robert, it looks like you'll trust acpi_table_parse if > pci_mmcfg_check_hostbridge returns a failure. I think it should be > treated with a higher priority. If pci_mmcfg_check_hostbridge returns a > failure, there's no way MCFG space can work, so we should disable it > unconditionally in that case (even if ACPI says "trust me, when have I > ever lied to you?"). > > I'm testing it now on my 965... Bah... nevermind Robert, I see you're doing this already in pci_mmcfg_reject_broken. I'm about to reboot & test now. Jesse - 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/