Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751453AbdCMHSX (ORCPT ); Mon, 13 Mar 2017 03:18:23 -0400 Received: from mail-wr0-f194.google.com ([209.85.128.194]:33119 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750763AbdCMHSP (ORCPT ); Mon, 13 Mar 2017 03:18:15 -0400 Date: Mon, 13 Mar 2017 08:18:10 +0100 From: Ingo Molnar To: "Kirill A. Shutemov" Cc: Linus Torvalds , Andrew Morton , x86@kernel.org, Thomas Gleixner , Ingo Molnar , Arnd Bergmann , "H. Peter Anvin" , Andi Kleen , Dave Hansen , Andy Lutomirski , Michal Hocko , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 21/26] x86/mm: add support of additional page table level during early boot Message-ID: <20170313071810.GA28726@gmail.com> References: <20170313055020.69655-1-kirill.shutemov@linux.intel.com> <20170313055020.69655-22-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170313055020.69655-22-kirill.shutemov@linux.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1307 Lines: 33 * Kirill A. Shutemov wrote: > This patch adds support for 5-level paging during early boot. > It generalizes boot for 4- and 5-level paging on 64-bit systems with > compile-time switch between them. > > Signed-off-by: Kirill A. Shutemov > --- > arch/x86/boot/compressed/head_64.S | 23 +++++++++-- > arch/x86/include/asm/pgtable.h | 2 +- > arch/x86/include/asm/pgtable_64.h | 6 ++- > arch/x86/include/uapi/asm/processor-flags.h | 2 + > arch/x86/kernel/espfix_64.c | 2 +- > arch/x86/kernel/head64.c | 40 +++++++++++++----- > arch/x86/kernel/head_64.S | 63 +++++++++++++++++++++-------- Ok, here I'd like to have a C version instead of further complicating an already complex assembly version... I.e. the existing setup code should be converted to C in one patch, and then another patch should add 5-level paging support to the C code. See how this was done for the 32-bit setup code already: 5a7670ee23f2 x86/boot/32: Convert the 32-bit pgtable setup code from assembly to C Also, please split it up into per boot path and topic, i.e. have a sparate patch for the Xen bits, the KASAN bits, the kexec extension, etc. Thanks, Ingo