Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758390Ab3FCO10 (ORCPT ); Mon, 3 Jun 2013 10:27:26 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:42896 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758040Ab3FCO1Z (ORCPT ); Mon, 3 Jun 2013 10:27:25 -0400 Message-ID: <1370269642.2910.4.camel@dabdike> Subject: Re: [PATCH 0/4] EFI 1:1 mapping From: James Bottomley To: Borislav Petkov Cc: Matthew Garrett , Linux EFI , Matt Fleming , Jiri Kosina , X86-ML , LKML , Borislav Petkov Date: Mon, 03 Jun 2013 07:27:22 -0700 In-Reply-To: <20130603081148.GB13607@nazgul.tnic> References: <1370177770-26661-1-git-send-email-bp@alien8.de> <20130602225620.GA5496@srcf.ucam.org> <20130603081148.GB13607@nazgul.tnic> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.8.2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1198 Lines: 25 On Mon, 2013-06-03 at 10:11 +0200, Borislav Petkov wrote: > On Sun, Jun 02, 2013 at 11:56:20PM +0100, Matthew Garrett wrote: > > I've just run Windows 8 under a hacked up copy of OVMF that dumps > > the data passed to SetVirtualAddressMap. It seems that Windows *is* > > mapping the runtime services to higher addresses - so presumably the > > 1:1 mapping is in addition to the virtual mapping. > > But but, once we call SetVirtualAddressMap with the set of addresses of > the runtime services, only those can be used after, right? If so, we > can't have both (this is at least my understanding)... That's correct. I think not calling SetVirtualAddressMap() and just using a 1:1 mapping is far safer (having looked at what tianocore does for SetVirtualAddressMap()). The chances are that all the UEFI bioses are only tested with windows, so the pointer chases it has to do to switch address maps only work with the operations windows does. James -- 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/