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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17B85C433E0 for ; Mon, 1 Mar 2021 10:42:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C36AC64E10 for ; Mon, 1 Mar 2021 10:42:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234639AbhCAKmG (ORCPT ); Mon, 1 Mar 2021 05:42:06 -0500 Received: from mga04.intel.com ([192.55.52.120]:50296 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234619AbhCAKlE (ORCPT ); Mon, 1 Mar 2021 05:41:04 -0500 IronPort-SDR: Rk9q/8hRGf7VkeAatb2r8/M67bXf7/ftm6qI2u/ebKzIzxHNvsSSeIDOl4WGgHbJ86lrLMzV1q 3IIQLWg3bWtg== X-IronPort-AV: E=McAfee;i="6000,8403,9909"; a="183979510" X-IronPort-AV: E=Sophos;i="5.81,215,1610438400"; d="scan'208";a="183979510" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Mar 2021 02:40:08 -0800 IronPort-SDR: GaiOkz5gyJCKZ91ddRGKNhnOfqGp7mrCPkU/lbJiKrSN64P232mI2W5THs8rmY6qLwNKbSNRJ8 H6dGUCRlxDhw== X-IronPort-AV: E=Sophos;i="5.81,215,1610438400"; d="scan'208";a="368557579" Received: from jscomeax-mobl.amr.corp.intel.com ([10.252.139.76]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Mar 2021 02:40:05 -0800 Message-ID: <7603ef673997b6674f785d333a4f263c749d2cf3.camel@intel.com> Subject: Re: [PATCH 02/25] x86/cpufeatures: Add SGX1 and SGX2 sub-features From: Kai Huang To: Borislav Petkov Cc: kvm@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org, seanjc@google.com, jarkko@kernel.org, luto@kernel.org, dave.hansen@intel.com, rick.p.edgecombe@intel.com, haitao.huang@intel.com, pbonzini@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Date: Mon, 01 Mar 2021 23:40:02 +1300 In-Reply-To: <20210301103043.GB6699@zn.tnic> References: <20210301100037.GA6699@zn.tnic> <3fce1dd2abd42597bde7ae9496bde7b9596b2797.camel@intel.com> <20210301103043.GB6699@zn.tnic> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.4 (3.38.4-1.fc33) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2021-03-01 at 11:30 +0100, Borislav Petkov wrote: > On Mon, Mar 01, 2021 at 11:19:15PM +1300, Kai Huang wrote: > > "sgx2" is useful because it adds additional functionality. > > Useful for what? SGX2 means "Enclave Dynamic Memory Management", which supports dynamically adding/removing EPC pages, plus changing page permission, after enclave is initialized. So it allows enclave author to write enclave in more flexible way, and also utilize EPC resource more efficiently. > > People have got to start explaining "why" something is useful and put > that "why" in the commit message. > Yes I can add "why" into commit message, but isn't the comment after X86_FEATURE_SGX2 enough? I think people who are interested in SGX will know what SGX2 is and why SGX2 is useful.