Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752802AbdHJOqn (ORCPT ); Thu, 10 Aug 2017 10:46:43 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:34441 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752317AbdHJOql (ORCPT ); Thu, 10 Aug 2017 10:46:41 -0400 Date: Thu, 10 Aug 2017 16:46:37 +0200 From: Ingo Molnar To: Matt Fleming Cc: Stuart Hayes , Ard Biesheuvel , "H. Peter Anvin" , linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH] x86/efi: page align EFI ROM image ranges Message-ID: <20170810144637.qpqqr5rs3lhag6av@gmail.com> References: <4a28637c-d5ff-95ed-5bee-2b1e465f2d79@gmail.com> <20170804120650.GE8187@codeblueprint.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170804120650.GE8187@codeblueprint.co.uk> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4095 Lines: 91 * Matt Fleming wrote: > On Wed, 02 Aug, at 11:41:38AM, Stuart Hayes wrote: > > (Resend because I mistyped the maintainer's email address the first time.) > > > > The kernel's EFI stub locates and copies EFI ROM images into memory, > > which it allocates using the byte-granular EFI allocate_pool > > function. These memory ranges are then added to setup_data, and > > later to e820 (in e820__reserve_setup_data()). The e820 ranges are > > parsed to create nosave regions (in > > e820__register_nosave_regions()), but when non-page-aligned e820 > > regions are parsed, a nosave page is added at the beginning and end > > of each non-page-aligned region, which results in data not getting > > saved or restored during a hibernate/resume. This can result in > > random failures after a hibernate/resume. > > > > Round up the allocation size to a whole number of pages, and use EFI > > allocate_pages to ensure that the EFI ROM copy regions are > > page-aligned. > > > > On a system with six EFI ROM images, before the patch: > > > > e820: update [mem 0x64866020-0x6486e05f] usable ==> usable > > e820: update [mem 0x6147a020-0x61499c5f] usable ==> usable > > e820: update [mem 0x60fff020-0x6105785f] usable ==> usable > > e820: update [mem 0x60fa6020-0x60ffe85f] usable ==> usable > > e820: update [mem 0x60f4d020-0x60fa585f] usable ==> usable > > e820: update [mem 0x60ef4020-0x60f4c85f] usable ==> usable > > ... > > PM: Registered nosave memory: [mem 0x00000000-0x00000fff] > > PM: Registered nosave memory: [mem 0x000a0000-0x000fffff] > > PM: Registered nosave memory: [mem 0x60ef4000-0x60ef4fff] > > PM: Registered nosave memory: [mem 0x60f4c000-0x60f4cfff] > > PM: Registered nosave memory: [mem 0x60f4d000-0x60f4dfff] > > PM: Registered nosave memory: [mem 0x60fa5000-0x60fa5fff] > > PM: Registered nosave memory: [mem 0x60fa6000-0x60fa6fff] > > PM: Registered nosave memory: [mem 0x60ffe000-0x60ffefff] > > PM: Registered nosave memory: [mem 0x60fff000-0x60ffffff] > > PM: Registered nosave memory: [mem 0x61057000-0x61057fff] > > PM: Registered nosave memory: [mem 0x6147a000-0x6147afff] > > PM: Registered nosave memory: [mem 0x61499000-0x61499fff] > > PM: Registered nosave memory: [mem 0x64866000-0x64866fff] > > PM: Registered nosave memory: [mem 0x6486e000-0x6486efff] > > PM: Registered nosave memory: [mem 0x6cf6e000-0x6f3ccfff] > > > > After the patch: > > > > e820: update [mem 0x64866000-0x6486efff] usable ==> usable > > e820: update [mem 0x6147a000-0x61499fff] usable ==> usable > > e820: update [mem 0x60fff000-0x61057fff] usable ==> usable > > e820: update [mem 0x60fa6000-0x60ffefff] usable ==> usable > > e820: update [mem 0x60f4d000-0x60fa5fff] usable ==> usable > > e820: update [mem 0x60ef4000-0x60f4cfff] usable ==> usable > > ... > > PM: Registered nosave memory: [mem 0x00000000-0x00000fff] > > PM: Registered nosave memory: [mem 0x000a0000-0x000fffff] > > PM: Registered nosave memory: [mem 0x6cf6e000-0x6f3ccfff] > > > > Signed-off-by: Stuart Hayes > > --- > > > > --- linux-4.13-rc2/arch/x86/boot/compressed/eboot.c.orig 2017-08-01 12:12:04.696049106 -0400 > > +++ linux-4.13-rc2/arch/x86/boot/compressed/eboot.c 2017-08-01 12:11:33.120182236 -0400 > > @@ -235,7 +235,12 @@ __setup_efi_pci64(efi_pci_io_protocol_64 > > > > size = pci->romsize + sizeof(*rom); > > > > - status = efi_call_early(allocate_pool, EFI_LOADER_DATA, size, &rom); > > + /* > > + * Get whole pages because this will be added to e820. > > + */ > > + size = PAGE_ALIGN(size); > > + status = efi_call_early(allocate_pages, EFI_ALLOCATE_ANY_PAGES, > > + EFI_LOADER_DATA, (size >> PAGE_SHIFT), &rom); > > if (status != EFI_SUCCESS) { > > efi_printk(sys_table, "Failed to alloc mem for rom\n"); > > return status; > > > > Nice catch. The comment could do with a little more information, > including the fact that it's the e820 nosave code that expects > page-aligned ROM regions. > > Also, you'll need the same fix for __setup_efi_pci32(). Just a quick ping: is this fix being worked on? Thanks, Ingo