From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id D1CA27D090 for ; Tue, 2 Oct 2018 16:37:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726572AbeJBXVu (ORCPT ); Tue, 2 Oct 2018 19:21:50 -0400 Received: from mail.skyhub.de ([5.9.137.197]:34574 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726233AbeJBXVu (ORCPT ); Tue, 2 Oct 2018 19:21:50 -0400 X-Virus-Scanned: Nedap ESD1 at mail.skyhub.de Received: from mail.skyhub.de ([127.0.0.1]) by localhost (blast.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id szLh2r-gqgaR; Tue, 2 Oct 2018 18:37:33 +0200 (CEST) Received: from zn.tnic (p200300EC2BC64F00329C23FFFEA6A903.dip0.t-ipconnect.de [IPv6:2003:ec:2bc6:4f00:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id BAEF61EC02D1; Tue, 2 Oct 2018 18:37:33 +0200 (CEST) Date: Tue, 2 Oct 2018 18:37:36 +0200 From: Borislav Petkov To: Dave Hansen , Yu-cheng Yu Cc: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue Subject: Re: [RFC PATCH v4 02/27] x86/fpu/xstate: Change some names to separate XSAVES system and user states Message-ID: <20181002163736.GD29601@zn.tnic> References: <20180921150351.20898-1-yu-cheng.yu@intel.com> <20180921150351.20898-3-yu-cheng.yu@intel.com> <20181002152903.GB29601@zn.tnic> <498c8824-9255-96be-71c2-3ebfa684a9d3@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <498c8824-9255-96be-71c2-3ebfa684a9d3@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Tue, Oct 02, 2018 at 09:30:52AM -0700, Dave Hansen wrote: > > Good point. However, "system" is more indicative; CET states are per-task and > > not "Supervisor". Do we want to go back to "Supervisor" or add comments? > > This is one of those things where the SDM language does not match what > we use in the kernel. I think it's fine to call them "system" or > "kernel" states to make it consistent with our existing in-kernel > nomenclature. > > I say add comments to clarify what the SDM calls it vs. what we do. So AFAIU, the difference is that XSAVES is a CPL0 insn. Thus the supervisor thing, I'd guess. Now it looks like CET uses XSAVES (from skimming the patchset forward) but then what our nomenclature is and how it all gets tied together, needs to be explained somewhere prominent so that we're all on the same page. This patch's commit message is not even close. So I'd very much appreciate a more verbose explanation, even if it repeats itself at places. Thx. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.