Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758047AbYHaT2R (ORCPT ); Sun, 31 Aug 2008 15:28:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756017AbYHaT2D (ORCPT ); Sun, 31 Aug 2008 15:28:03 -0400 Received: from casper.infradead.org ([85.118.1.10]:51352 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755906AbYHaT2B (ORCPT ); Sun, 31 Aug 2008 15:28:01 -0400 Date: Sun, 31 Aug 2008 12:27:51 -0700 From: Arjan van de Ven To: Linus Torvalds Cc: David Sanders , linux-kernel@vger.kernel.org, Jan Beulich , Andi Kleen , Ingo Molnar , Thomas Gleixner Subject: Re: [BUG] x86 kenel won't boot under Virtual PC Message-ID: <20080831122751.72afafb5@infradead.org> In-Reply-To: References: <200808311422.12525.linux@sandersweb.net> Organization: Intel X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.11; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1259 Lines: 32 On Sun, 31 Aug 2008 11:47:04 -0700 (PDT) Linus Torvalds wrote: > > > On Sun, 31 Aug 2008, David Sanders wrote: > > > > I recently discovered that x86 kernels won't boot under Virtual PC. > > What CPU does Virtual PC emulate? As far as Wikipedia is concerned > (not that I'd take it on complete faith) it emulates a 32-bit Intel > Pentium II. > > And that commit makes the kernel use the "P6 nops" for such hardware. > Maybe Virtual PC doesn't support the newer intel nop things? > > Intel docs say that it should be available on any intel CPU that has > CPUID.01H.EAX[11:8] = 0110B or 1111B. That's the "family ID", and > Pentium II should have a family ID of 6 (ie that 0110B case). > > So it sounds like a Virtual PC bug, but I dunno. And maybe we should > just use the legcay nops for anything that isn't modern (ie P4+ or > Core)? it's probably even a security bug in that I don't see what would be stopping a ring 3 user process from executing these instructions... -- 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/