From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D66CAC433F5 for ; Thu, 17 Mar 2022 13:26:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234555AbiCQN16 (ORCPT ); Thu, 17 Mar 2022 09:27:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234596AbiCQN1v (ORCPT ); Thu, 17 Mar 2022 09:27:51 -0400 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C8DE16C0A5; Thu, 17 Mar 2022 06:26:34 -0700 (PDT) Received: from mail.ispras.ru (unknown [83.149.199.84]) by mail.ispras.ru (Postfix) with ESMTPSA id 784C840D4004; Thu, 17 Mar 2022 13:26:28 +0000 (UTC) MIME-Version: 1.0 Date: Thu, 17 Mar 2022 16:26:28 +0300 From: baskov@ispras.ru To: Matthew Garrett Cc: Ard Biesheuvel , Peter Jones , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , X86 ML , linux-efi , Linux Kernel Mailing List , bret.barkelew@microsoft.com Subject: Re: [PATCH RFC v2 0/2] Handle UEFI NX-restricted page tables In-Reply-To: <20220303204759.GA20294@srcf.ucam.org> References: <20220224154330.26564-1-baskov@ispras.ru> <20220228183044.GA18400@srcf.ucam.org> <9787f1c1948cc640e70a50e4b929f44f@ispras.ru> <20220303204759.GA20294@srcf.ucam.org> User-Agent: Roundcube Webmail/1.4.4 Message-ID: <9b8493626c3c6c0af415e0b277147f9e@ispras.ru> X-Sender: baskov@ispras.ru Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org On 2022-03-03 23:47, Matthew Garrett wrote: > > Ok. I think this should really go through the UEFI spec process - I > agree that from a strict interpretation of the spec, what this firmware > is doing is legitimate, but I don't like having a situation where we > have to depend on the DXE spec. > > How does Windows handle this? Just update the page tables itself for > any > regions it needs during boot? Sorry for delay. Windows is closed source, so we cannot give guarantees on its behavior, but this is our belief regarding its behavior. Added Bret Barkelew (bret.barkelew@microsoft.com) to the CC-list in case he can add something. Regarding the spec changes, we agree it is reasonable, but whether the spec changes or not it will take some time to update the edk2. Our first solution was safer in regards to the use of the services, yet as Ard suggested, using DXE services is much cleaner as long as it works. We can post it to edk2-devel, but our opinion is that these issues are independent. Thanks, Baskov Evgeniy