From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759217AbYE0U7q (ORCPT ); Tue, 27 May 2008 16:59:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758055AbYE0U7g (ORCPT ); Tue, 27 May 2008 16:59:36 -0400 Received: from www.tglx.de ([62.245.132.106]:43966 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757958AbYE0U7g (ORCPT ); Tue, 27 May 2008 16:59:36 -0400 Date: Tue, 27 May 2008 22:58:37 +0200 (CEST) From: Thomas Gleixner To: Jeremy Fitzhardinge cc: Yinghai Lu , Ingo Molnar , "H. Peter Anvin" , Andrew Morton , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] x86: extend e820 ealy_res support 32bit - fix #2 In-Reply-To: <483C70F9.2030901@goop.org> Message-ID: References: <200805110030.15510.yhlu.kernel@gmail.com> <200805180118.57863.yhlu.kernel@gmail.com> <200805211840.18619.yhlu.kernel@gmail.com> <200805251000.10205.yhlu.kernel@gmail.com> <483C70F9.2030901@goop.org> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 27 May 2008, Jeremy Fitzhardinge wrote: > Thomas Gleixner wrote: > > On Sun, 25 May 2008, Yinghai Lu wrote: > > > > > remove extra -1 in reseve_early calling > > > panic if can not find space for new RAMDISK > > > > > > > > > > Thanks, applied on top of the v2 update > > > > tglx > > > This patch is still required to make Xen boot with the e820 changes: Ok. This one was not in the queue you sent ? Will pick it up. Thanks, tglx > Subject: xen: boot via i386_start_kernel to get early reservations > > Boot Xen via i386_start_kernel so that all the early reservations are > made properly; without these, it will start using the kernel and > pagetables as early heap memory, which is a bit suboptimal. > > One tricky part is that reserve_early() will just panic if any of the > early reservations overlap any others. When a Xen domain is built, it > constructs the initial address space as: > > kernel text+data+bss > initrd > inital pagetable > > Therefore, when reserving the pagetable (from &_end to > init_pg_tables_end), it covers the whole initrd area. If it then > tries to reserve the initrd, it will panic because of the overlap. > > The simple fix here is to reserve INIT_PG_TABLE first, and then only > reserve the ramdisk if it doesn't overlap with the previous > reservations. A better/more complex fix might be to make > reserve_early() deal with overlapping reservations. > > Signed-off-by: Jeremy Fitzhardinge > --- > arch/x86/kernel/head32.c | 6 ++++-- > arch/x86/xen/enlighten.c | 2 +- > include/asm-x86/setup.h | 1 + > 3 files changed, 6 insertions(+), 3 deletions(-) > > =================================================================== > --- a/arch/x86/kernel/head32.c > +++ b/arch/x86/kernel/head32.c > @@ -66,6 +66,7 @@ void __init i386_start_kernel(void) > void __init i386_start_kernel(void) > { > reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA > BSS"); > + reserve_early(__pa_symbol(&_end), init_pg_tables_end, > "INIT_PG_TABLE"); > > #ifdef CONFIG_BLK_DEV_INITRD > /* Reserve INITRD */ > @@ -73,10 +74,11 @@ void __init i386_start_kernel(void) > u64 ramdisk_image = boot_params.hdr.ramdisk_image; > u64 ramdisk_size = boot_params.hdr.ramdisk_size; > u64 ramdisk_end = ramdisk_image + ramdisk_size; > - reserve_early(ramdisk_image, ramdisk_end, "RAMDISK"); > + if (ramdisk_end < __pa_symbol(&_text) || > + ramdisk_image >= init_pg_tables_end) > + reserve_early(ramdisk_image, ramdisk_end, "RAMDISK"); > } > #endif > - reserve_early(__pa_symbol(&_end), init_pg_tables_end, > "INIT_PG_TABLE"); > > reserve_ebda_region(); > > =================================================================== > --- a/arch/x86/xen/enlighten.c > +++ b/arch/x86/xen/enlighten.c > @@ -1264,5 +1264,5 @@ asmlinkage void __init xen_start_kernel( > } > > /* Start the world */ > - start_kernel(); > + i386_start_kernel(); > } > =================================================================== > --- a/include/asm-x86/setup.h > +++ b/include/asm-x86/setup.h > @@ -58,6 +58,7 @@ int __init copy_e820_map(struct e820entr > int __init copy_e820_map(struct e820entry *biosmap, int nr_map); > void __init add_memory_region(unsigned long long start, > unsigned long long size, int type); > +void __init i386_start_kernel(void); > > extern unsigned long init_pg_tables_end; > > >