From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753079AbZDMEZ4 (ORCPT ); Mon, 13 Apr 2009 00:25:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751221AbZDMEZq (ORCPT ); Mon, 13 Apr 2009 00:25:46 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:52819 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750720AbZDMEZp (ORCPT ); Mon, 13 Apr 2009 00:25:45 -0400 Date: Mon, 13 Apr 2009 06:24:59 +0200 From: Ingo Molnar To: Avi Kivity Cc: Linus Torvalds , "H. Peter Anvin" , Pavel Machek , mingo@redhat.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@linux.intel.com, rjw@sisk.pl, linux-tip-commits@vger.kernel.org Subject: Re: [tip:x86/setup] x86, setup: "glove box" BIOS calls -- infrastructure Message-ID: <20090413042459.GA6479@elte.hu> References: <20090410103934.GA21506@elte.hu> <20090410104648.GA31516@elf.ucw.cz> <20090410112546.GD21506@elte.hu> <20090410113824.GA18823@elf.ucw.cz> <49E0C1AB.2050608@redhat.com> <49E17A6E.5000104@zytor.com> <20090412163356.GA2392@elte.hu> <49E2398A.3050405@redhat.com> <20090413041625.GF11652@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090413041625.GF11652@elte.hu> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar wrote: > > * Avi Kivity wrote: > > > Ingo Molnar wrote: > >>> Sure, go ahead and wrap them in some kind of "save and restore all > >>> registers" wrapping, but nothing fancier than that. It would just be > >>> overkill, and likely to break more than it fixes. > >>> > >> > >> Yeah. I only brought up the virtualization thing as a > >> hypothetical: "if" corrupting the main OS ever became a > >> widespread problem. Then i made the argument that this is > >> unlikely to happen, because Windows will be affected by it just > >> as much. (while register state corruptions might go unnoticed > >> much more easily, just via the random call-environment clobbering > >> of registers by Windows itself.) > >> > >> The only case where i could see virtualization to be useful is > >> the low memory RAM corruption pattern that some people have > >> observed. > > > > You could easily check that by checksumming pages (or actually > > copying them to high memory) before the call, and verifying after > > the call. > > Yes, we could do memory checks, and ... hey, we already do that: > > bb577f9: x86: add periodic corruption check > 5394f80: x86: check for and defend against BIOS memory corruption > > ... and i seem to be the one who implemented it! ;-) s/implemented/merged+fixed :-) Ingo