Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758746AbYCEQCx (ORCPT ); Wed, 5 Mar 2008 11:02:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756521AbYCEQCc (ORCPT ); Wed, 5 Mar 2008 11:02:32 -0500 Received: from mx1.redhat.com ([66.187.233.31]:44721 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756247AbYCEQCb (ORCPT ); Wed, 5 Mar 2008 11:02:31 -0500 Date: Wed, 5 Mar 2008 12:59:31 -0300 From: Eduardo Habkost To: Ian Campbell Cc: "H. Peter Anvin" , Alexander van Heukelum , Ingo Molnar , Alexander van Heukelum , Andi Kleen , Thomas Gleixner , Jeremy Fitzhardinge , Mark McLoughlin , LKML Subject: Re: [RFC] use realmode code to reserve end-of-conventional-memory to 1MB Message-ID: <20080305155930.GI20230@blackpad> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1204240609.28798.33.camel@cthulhu.hellion.org.uk> X-Fnord: you can see the fnord User-Agent: Mutt/1.5.14 (2007-02-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2027 Lines: 53 On Thu, Feb 28, 2008 at 11:16:49PM +0000, Ian Campbell wrote: > > 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). > > However ddcprobe hangs when run -- need to investigate some more, vm86 > in general works ok (i.e. my vm86 test code passes). > > BTW Jeremy, the kernel doesn't use XENMEM_memory_map -- any reason other > than it not being useful at the time? These days the tools can push an > arbitrary e820 down for a guest which might be useful to support, > although nothing interesting is done with it today. > > Ian. > > 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); Won't this waste 300+ KB of Perfectly Good RAM? Or I understood it incorrectly? I am aware that it would take more work to tell all kernel code that it shouldn't look for BIOS data on this region when running as a domU guest, but it seems that it would be a better solution. -- Eduardo -- 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/