From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751086AbdE3Qjb (ORCPT ); Tue, 30 May 2017 12:39:31 -0400 Received: from mail-bn3nam01on0083.outbound.protection.outlook.com ([104.47.33.83]:30680 "EHLO NAM01-BN3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750821AbdE3Qj1 (ORCPT ); Tue, 30 May 2017 12:39:27 -0400 Authentication-Results: google.com; dkim=none (message not signed) header.d=none;google.com; dmarc=none action=none header.from=amd.com; Subject: Re: [PATCH v5 29/32] x86/mm: Add support to encrypt the kernel in-place To: Borislav Petkov CC: , , , , , , , , , , Rik van Riel , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Toshimitsu Kani , Arnd Bergmann , Jonathan Corbet , Matt Fleming , "Michael S. Tsirkin" , Joerg Roedel , Konrad Rzeszutek Wilk , Paolo Bonzini , Larry Woodman , Brijesh Singh , Ingo Molnar , Andy Lutomirski , "H. Peter Anvin" , Andrey Ryabinin , Alexander Potapenko , Dave Young , Thomas Gleixner , Dmitry Vyukov References: <20170418211612.10190.82788.stgit@tlendack-t1.amdoffice.net> <20170418212149.10190.70894.stgit@tlendack-t1.amdoffice.net> <20170518124626.hqyqqbjpy7hmlpqc@pd.tnic> <7e2ae014-525c-76f2-9fce-2124596db2d2@amd.com> <20170526162522.p7prrqqalx2ivfxl@pd.tnic> From: Tom Lendacky Message-ID: <33c075b1-71f6-b5d0-b1fa-d742d0659d38@amd.com> Date: Tue, 30 May 2017 11:39:07 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <20170526162522.p7prrqqalx2ivfxl@pd.tnic> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [165.204.78.1] X-ClientProxiedBy: MWHPR15CA0035.namprd15.prod.outlook.com (10.173.226.149) To MWHPR12MB1149.namprd12.prod.outlook.com (10.169.204.13) X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MWHPR12MB1149: 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25, 2017 at 05:24:27PM -0500, Tom Lendacky wrote: >> I guess I could do that, but this will probably only end up clearing a >> single PGD entry anyway since it's highly doubtful the address range >> would cross a 512GB boundary. > > Or you can compute how many 512G-covering, i.e., PGD entries there are > and clear just the right amnount. :^) > >> I can change the name. As for the use of ENTRY... without the >> ENTRY/ENDPROC combination I was receiving a warning about a return >> instruction outside of a callable function. It looks like I can just >> define the "sme_enc_routine:" label with the ENDPROC and the warning >> goes away and the global is avoided. It doesn't like the local labels >> (.L...) so I'll use the new name. > > Is that warning from objtool or where does it come from? Yes, it's from objtool: arch/x86/mm/mem_encrypt_boot.o: warning: objtool: .text+0xd2: return instruction outside of a callable function > > How do I trigger it locally I think having CONFIG_STACK_VALIDATION=y will trigger it. > >> The hardware will try to optimize rep movsb into large chunks assuming >> things are aligned, sizes are large enough, etc. so we don't have to >> explicitly specify and setup for a rep movsq. > > I thought the hw does that for movsq too? It does. Thanks, Tom >