From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH] kvmtool: don't use PCI config space IRQ line field Date: Fri, 6 Feb 2015 18:55:27 +0000 Message-ID: <20150206185527.GC24099@arm.com> References: <4324891.mqG6Yyfi6J@wuerfel> <1423064390-15269-1-git-send-email-andre.przywara@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "penberg@kernel.org" , "arnd@arndb.de" , "linux-arm-kernel@lists.infradead.org" , "kvmarm@lists.cs.columbia.edu" , "kvm@vger.kernel.org" , Marc Zyngier To: Andre Przywara Return-path: Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:42473 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751053AbbBFSzb (ORCPT ); Fri, 6 Feb 2015 13:55:31 -0500 Content-Disposition: inline In-Reply-To: <1423064390-15269-1-git-send-email-andre.przywara@arm.com> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Feb 04, 2015 at 03:39:50PM +0000, Andre Przywara wrote: > In PCI config space there is an interrupt line field (offset 0x3f), > which is used to initially communicate the IRQ line number from > firmware to the OS. _Hardware_ should never use this information, > as the OS is free to write any information in there. Is this true even with probe-only? I appreciate that this isn't a BAR, but it still feels odd for Linux to write this in that case. Will