Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756100AbcLBRxT (ORCPT ); Fri, 2 Dec 2016 12:53:19 -0500 Received: from terminus.zytor.com ([198.137.202.10]:56186 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752551AbcLBRxR (ORCPT ); Fri, 2 Dec 2016 12:53:17 -0500 User-Agent: K-9 Mail for Android In-Reply-To: <20161202160855.GA3307@gmail.com> References: <1476468318-24422-1-git-send-email-boris.ostrovsky@oracle.com> <1476468318-24422-3-git-send-email-boris.ostrovsky@oracle.com> <0b9894e4-753c-7e49-45a7-3ee5e82abe3e@oracle.com> <03294a9e-63b2-3cea-2dfe-808190f6fa0e@oracle.com> <20161202094554.GA28775@gmail.com> <20161202160855.GA3307@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Subject: Re: [PATCH 2/8] x86/head: Refactor 32-bit pgtable setup From: hpa@zytor.com Date: Fri, 02 Dec 2016 09:52:44 -0800 To: Ingo Molnar , Boris Ostrovsky CC: Thomas Gleixner , Ingo Molnar , david.vrabel@citrix.com, JGross@suse.com, roger.pau@citrix.com, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, Matt Fleming Message-ID: <3F5DA9BC-52BF-4025-AAB9-24C943BDB711@zytor.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1668 Lines: 51 On December 2, 2016 8:08:55 AM PST, Ingo Molnar wrote: > >* Boris Ostrovsky wrote: > >> On 12/02/2016 04:45 AM, Ingo Molnar wrote: >> > * Boris Ostrovsky wrote: >> > >> >> On 10/31/2016 08:33 AM, Boris Ostrovsky wrote: >> >>> >> >>> On 10/14/2016 02:05 PM, Boris Ostrovsky wrote: >> >>>> From: Matt Fleming >> >>>> >> >>>> The new Xen PVH entry point requires page tables to be setup by >the >> >>>> kernel since it is entered with paging disabled. >> >>>> >> >>>> Pull the common code out of head_32.S and into pgtable_32.S so >that >> >>>> setup_pgtable_32 can be invoked from both the new Xen entry >point and >> >>>> the existing startup_32 code. >> >>> >> >>> Ping to x86 maintainers. >> >> Pinging again. >> >> >> >> I will be re-sending this series at some point (it has been >delayed by >> >> some hypervisor changes that will be needed) but I'd like to hear >from >> >> x86 maintainers whether this will be acceptable before I post this >again. >> > Could this be done in C? >> >> I suppose it could be, I haven't thought about it. >> >> The goal here was to simply make existing startup code available to >others (Xen >> guest) without changes. Are you suggesting to build page tables in C >for the Xen >> guest only or to make startup_32 call new C code as well? > >My suggestion would be to transform the factored out assembly code to >C. > >Thanks, > > Ingo It is tricky to do so safely, because at this stage almost nothing of the C execution environment has been set up. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.