From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933965AbYBGA5d (ORCPT ); Wed, 6 Feb 2008 19:57:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964793AbYBGAyD (ORCPT ); Wed, 6 Feb 2008 19:54:03 -0500 Received: from ug-out-1314.google.com ([66.249.92.175]:18661 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934548AbYBGAx7 (ORCPT ); Wed, 6 Feb 2008 19:53:59 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:to:cc:subject:message-id:references:mime-version:content-type:content-disposition:in-reply-to:user-agent:from; b=fEoceINA04a14wJxz+iO3m0HhdlZgunkHGtICiJ0OnihsNaxNzwJ1cqBf0kP4X8AGEBeM7ftZyRPLot4cNVTGJtHmdNCVVcEcliMOOtPF8ef5zoRhtKYnILOVoc8vvJPhsdAA3B5qkmmWXx6FCgK/trjb4SHy1GiCbw3T33yaY4= Date: Thu, 7 Feb 2008 02:51:20 +0200 To: Ingo Molnar Cc: Rusty Russel , Suresh Siddha , Thomas Gleixner , lguest@ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH] lguest: Accept guest _PAGE_PWT page table entries Message-ID: <20080207005120.GA5751@ubuntu> References: <20080206232134.GB6450@ubuntu> <20080206235923.GA19843@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080206235923.GA19843@elte.hu> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) From: "Ahmed S. Darwish" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 07, 2008 at 12:59:23AM +0100, Ingo Molnar wrote: > > * Ahmed S. Darwish wrote: > > > Hi all, > > > > Beginning from commit 4138cc3418f5, ioremap_nocache() sets the _PAGE_PWT > > flag. > > > > Lguest doesn't accept a guest pte with a _PWT flag and reports a "bad > > page table entry" in that case. > > > > I've removed check from lguest code and everything worked fine. Is > > this safe from the Lguest side ? > > yes, should be safe. Could you send a patch so that others can apply it > too? > Ofcourse :) : Accept guest _PAGE_PWT page table entries, otherwise lguest will always fail with a "bad page table entry" message. Signed-off-by: Ahmed S. Darwish --- diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c index 74b4cf2..952160b 100644 --- a/drivers/lguest/page_tables.c +++ b/drivers/lguest/page_tables.c @@ -178,8 +178,8 @@ static void release_pte(pte_t pte) static void check_gpte(struct lg_cpu *cpu, pte_t gpte) { - if ((pte_flags(gpte) & (_PAGE_PWT|_PAGE_PSE)) - || pte_pfn(gpte) >= cpu->lg->pfn_limit) + if ((pte_flags(gpte) & _PAGE_PSE) || + pte_pfn(gpte) >= cpu->lg->pfn_limit) kill_guest(cpu, "bad page table entry"); } Regards, -- Ahmed S. Darwish Homepage: http://darwish.07.googlepages.com Blog: http://darwish-07.blogspot.com