Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763751AbYCDLmk (ORCPT ); Tue, 4 Mar 2008 06:42:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754571AbYCDLmc (ORCPT ); Tue, 4 Mar 2008 06:42:32 -0500 Received: from mx1.redhat.com ([66.187.233.31]:56189 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753025AbYCDLmb (ORCPT ); Tue, 4 Mar 2008 06:42:31 -0500 Subject: Re: [RFC] use realmode code to reserve end-of-conventional-memory to 1MB From: Mark McLoughlin Reply-To: Mark McLoughlin To: Ian Campbell Cc: "H. Peter Anvin" , Alexander van Heukelum , Ingo Molnar , Alexander van Heukelum , Andi Kleen , Thomas Gleixner , Jeremy Fitzhardinge , LKML In-Reply-To: <1204240609.28798.33.camel@cthulhu.hellion.org.uk> References: <20080224174605.GA21661@mailshack.com> <47C22568.1010405@zytor.com> <1203958478.20033.1239002461@webmail.messagingengine.com> <20080225170134.GA15839@elte.hu> <20080225180750.GA31054@mailshack.com> <20080228131341.GA25213@mailshack.com> <20080228132822.GA25278@mailshack.com> <1204233131.28798.12.camel@cthulhu.hellion.org.uk> <47C72432.3010606@zytor.com> <1204240609.28798.33.camel@cthulhu.hellion.org.uk> Content-Type: text/plain Date: Tue, 04 Mar 2008 11:41:46 +0000 Message-Id: <1204630906.16613.4.camel@muff> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 (2.12.3-1.fc8) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1775 Lines: 50 On Thu, 2008-02-28 at 23:16 +0000, Ian Campbell wrote: > On Thu, 2008-02-28 at 13:14 -0800, H. Peter Anvin wrote: > > > > You need to set up your memory map more sensibly; it's not just the > > kernel, user space tries to access these areas too. > > Agreed, I think it's pure luck that Xen kernels have gotten away with it > in the past. > > The patch below seems like the right thing to do. It certainly boots in > a domU without the DMI problem (without any of the other related patches > such as Alexander's). Yep, this patch on its own fixes 2.6.25-rc3 DomU boot for me here. > x86/xen: Construct e820 map with a hole between 640K-1M. > > Signed-off-by: Ian Campbell > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: H. Peter Anvin > Cc: Jeremy Fitzhardinge > --- > arch/x86/xen/setup.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c > index 3bad477..2341492 100644 > --- a/arch/x86/xen/setup.c > +++ b/arch/x86/xen/setup.c > @@ -38,7 +38,8 @@ char * __init xen_memory_setup(void) > unsigned long max_pfn = xen_start_info->nr_pages; > > e820.nr_map = 0; > - add_memory_region(0, PFN_PHYS(max_pfn), E820_RAM); > + add_memory_region(0, LOWMEMSIZE(), E820_RAM); > + add_memory_region(HIGH_MEMORY, PFN_PHYS(max_pfn)-HIGH_MEMORY, E820_RAM); Seems to me to be the right thing to do ... Acked-by: Mark McLoughlin Cheers, Mark. -- 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/