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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 A7ED2C433E0 for ; Sun, 21 Feb 2021 20:38:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 758F164E86 for ; Sun, 21 Feb 2021 20:38:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231322AbhBUUii (ORCPT ); Sun, 21 Feb 2021 15:38:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230280AbhBUUih (ORCPT ); Sun, 21 Feb 2021 15:38:37 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95EDEC061574; Sun, 21 Feb 2021 12:37:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description; bh=TodMQhTq+cGVVOCaD81EhvMNZtfQt3L+a/bV5YenmcA=; b=iErmknlTcb1M7IRQXgT7TBPyaO HSbSyds3TPXzWMgvu9MopiUz5HPxmmbw2d7UvJrSOLBQOzz9pEQNYJdtyaJuX1MbfBd5u059mn9k9 MdupbdNr4jSeVlQD7kVqELaqVmduU8KegPUIxqtNWZb6qoLD6z+pcMl6MUvlYwrgremIlMMocf4JW jVKX2d8seEIwUUcCAicqDqUEeJ84rpZ6lBOzwUa5BlDU8rs25zkak0hm7cW8Y7Xj+RKliYz+lAvXw tgZXyzTEuX5BGYG8BzqFLdLoLpGuSE65A0PRAvOMK2GIV4Fat8WWpCr8DNCnFibrqmYOQUa3XRgNP lCo8DIeA==; Received: from [2601:1c0:6280:3f0::d05b] by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1lDvUH-0000HV-J4; Sun, 21 Feb 2021 20:37:53 +0000 Subject: Re: [PATCH v4 22/22] x86/fpu/xstate: Introduce boot-parameters to control state component support To: "Bae, Chang Seok" Cc: Borislav Petkov , "luto@kernel.org" , "tglx@linutronix.de" , "mingo@kernel.org" , "x86@kernel.org" , "Brown, Len" , "Hansen, Dave" , "Liu, Jing2" , "Shankar, Ravi V" , "linux-kernel@vger.kernel.org" , "linux-doc@vger.kernel.org" References: <20210221185637.19281-1-chang.seok.bae@intel.com> <20210221185637.19281-23-chang.seok.bae@intel.com> <4862AEE9-1819-43A7-BF95-C02DB6E2D06D@intel.com> From: Randy Dunlap Message-ID: <40a65a30-ce41-6a51-50f4-34a0b0b1ef6f@infradead.org> Date: Sun, 21 Feb 2021 12:37:46 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <4862AEE9-1819-43A7-BF95-C02DB6E2D06D@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/21/21 12:10 PM, Bae, Chang Seok wrote: > On Feb 21, 2021, at 11:30, Randy Dunlap wrote: >> Can we tell people (in this Doc file) where to look up the values that can be >> used in xstate.enable and xstate.disable? > > Perhaps add something like this with the change below: > “See comment before function fpu__init_parse_early_param() in > arch/x86/kernel/fpu/init.c." Hi, I was thinking more along the lines of where can I find the value 0x60000 or BIT(22) or BIT(19), for example and see what they mean, even though it will likely be some abbreviation. > /* > * The kernel parameter "xstate.enable='mask'" and "xstate.disable='mask'" have a > * mask value in a subset of XFEATURE_MASK_CONFIGURABLE. > * > * The longest parameter is 22 octal number characters with '0' prefix and an extra > * '\0' for termination. > */ > #define MAX_XSTATE_MASK_CHARS 24 > > /** > * fpu__init_parse_early_param() - parse the xstate kernel parameters > * > * Parse them early because fpu__init_system() is executed before > * parse_early_param(). > */ > static void __init fpu__init_parse_early_param(void) thanks. -- ~Randy