Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161176Ab3FTWgG (ORCPT ); Thu, 20 Jun 2013 18:36:06 -0400 Received: from terminus.zytor.com ([198.137.202.10]:51333 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161077Ab3FTWgE (ORCPT ); Thu, 20 Jun 2013 18:36:04 -0400 Message-ID: <51C383AC.4060706@zytor.com> Date: Thu, 20 Jun 2013 15:35:24 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130514 Thunderbird/17.0.6 MIME-Version: 1.0 To: Borislav Petkov CC: Matthew Garrett , James Bottomley , Ingo Molnar , Linux EFI , Matt Fleming , X86 ML , LKML , Borislav Petkov Subject: Re: [PATCH -v2 0/4] EFI 1:1 mapping References: <1371740019.2372.3.camel@dabdike> <20130620162916.GA25727@srcf.ucam.org> <1371746775.2372.11.camel@dabdike> <20130620165426.GB26214@srcf.ucam.org> <20130620170124.GA19877@pd.tnic> <20130620171210.GA26593@srcf.ucam.org> <20130620180808.GB19877@pd.tnic> <20130620181015.GA27833@srcf.ucam.org> <20130620181445.GA791@pd.tnic> <20130620181731.GA27960@srcf.ucam.org> <20130620184736.GC19877@pd.tnic> In-Reply-To: <20130620184736.GC19877@pd.tnic> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1088 Lines: 41 On 06/20/2013 11:47 AM, Borislav Petkov wrote: > > I guess we can do a top-down allocation, starting from the highest > virtual addresses: > > EFI_HIGHEST_ADDRESS > | > | size1 > | > --> region1 > | > | size2 > | > --> region2 > > ... > > and we make EFI_HIGHEST_ADDRESS be the same absolute number on every > system. > > hpa, is this close to what you had in mind? It would be prudent to > verify whether this will suit well with the kexec virtual space layout > though... > This would work really well, I think. The tricky part here is to pick a safe EFI_HIGHEST_ADDRESS as it is an ABI. My preference would be to make EFI_HIGHEST_ADDRESS = -4 GB, which is *not* what Windows uses, but will leave the high negative range clear, and allows a range where we can grow down without much risk of interfering with anything else. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/