From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965106Ab3FTJN3 (ORCPT ); Thu, 20 Jun 2013 05:13:29 -0400 Received: from mail-ee0-f43.google.com ([74.125.83.43]:34296 "EHLO mail-ee0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755966Ab3FTJNZ (ORCPT ); Thu, 20 Jun 2013 05:13:25 -0400 Date: Thu, 20 Jun 2013 11:13:21 +0200 From: Ingo Molnar To: Matthew Garrett Cc: Borislav Petkov , Linux EFI , Matt Fleming , X86 ML , LKML , Borislav Petkov Subject: Re: [PATCH -v2 0/4] EFI 1:1 mapping Message-ID: <20130620091321.GB6811@gmail.com> References: <1371491416-11037-1-git-send-email-bp@alien8.de> <20130619125243.GD11209@gmail.com> <20130619130225.GA28311@pd.tnic> <20130619130434.GB24957@gmail.com> <20130619160804.GB27832@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130619160804.GB27832@srcf.ucam.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Matthew Garrett wrote: > On Wed, Jun 19, 2013 at 03:04:34PM +0200, Ingo Molnar wrote: > > * Borislav Petkov wrote: > > > And yet there are the Macs which reportedly cannot stomach this. > > > > Do we know why? > > I got lost in a maze of pointer arithmetic. There seems to be an > assumption that nvram writes should be forbidden if in runtime mode but > with pointers still below the phys/virt split, which obviously makes no > sense but hey. > > But, as always, the only reliable thing to do here is to behave as much > like Windows as possible. [...] Amen ... > [...] Which means performing the 1:1 mapping but maintaining the high > mapping, and passing the high values via SetVirtualAddressMap. Cool - and supposedly this will work in a Mac environment as well? Would be very nice to avoid fundamentally fragile system specific quirks for something as fundamental as the EFI runtime memory mapping model ... Thanks, Ingo