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 4D41AC433FE for ; Mon, 21 Nov 2022 15:30:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232448AbiKUPaN (ORCPT ); Mon, 21 Nov 2022 10:30:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232445AbiKUP3y (ORCPT ); Mon, 21 Nov 2022 10:29:54 -0500 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13938DF80; Mon, 21 Nov 2022 07:29:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669044547; x=1700580547; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=0ocp0OORCesdWMSJVXSnmGTZ9TeQKI/Q0W1c3l/hfEc=; b=RB44sEk/538mMBQfzjhVtI1ojIeGhQxQ4OQlMuEhOSbNIG6BolrypVxl 4Q9AB42NSNFOauk0smPNG1ADTBH6FnCPZ6fBvi5oBTlOWnApOdIr+UWbQ ggfcmwtVD5id1OVsjBUVT93qHjnhqBpZG/MrS7nTetZuusAmj385581q9 4QdbMp/LbVjUae5Zgh9b6c41Jiq6LdzEQaqeisEICIPQ+ytER1nMacSj7 SYqjOc2cZq9rwjLYMW3YgnZCu5KdyiT3Dvk8+pvOvDzpBIz3Hg75PpKJK Zv2+JMYfc+bsLFRjNhYzVdg5FP2PtIYTbzaNtf046/HCubKkG9YeWzbiy w==; X-IronPort-AV: E=McAfee;i="6500,9779,10538"; a="377843943" X-IronPort-AV: E=Sophos;i="5.96,181,1665471600"; d="scan'208";a="377843943" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Nov 2022 07:29:06 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10538"; a="730043155" X-IronPort-AV: E=Sophos;i="5.96,181,1665471600"; d="scan'208";a="730043155" Received: from ticela-or-327.amr.corp.intel.com (HELO [10.209.6.63]) ([10.209.6.63]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Nov 2022 07:29:04 -0800 Message-ID: <6d7fae50-ef3c-dc1e-336c-691095007117@intel.com> Date: Mon, 21 Nov 2022 07:29:04 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: Re: [PATCH v4 1/6] x86: KVM: Advertise CMPccXADD CPUID to user space Content-Language: en-US To: Jiaxi Chen Cc: kvm@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, seanjc@google.com, pbonzini@redhat.com, ndesaulniers@google.com, alexandre.belloni@bootlin.com, peterz@infradead.org, jpoimboe@kernel.org, chang.seok.bae@intel.com, pawan.kumar.gupta@linux.intel.com, babu.moger@amd.com, jmattson@google.com, sandipan.das@amd.com, tony.luck@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, fenghua.yu@intel.com, keescook@chromium.org, nathan@kernel.org, linux-kernel@vger.kernel.org References: <20221118141509.489359-1-jiaxi.chen@linux.intel.com> <20221118141509.489359-2-jiaxi.chen@linux.intel.com> From: Dave Hansen In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 11/21/22 06:46, Jiaxi Chen wrote: > Features which has been enabled in kernel usually should be added to > /proc/cpuinfo. Features that the kernel *itself* is actually using always get in there. Things like "smep". But, things that the kernel "enables" but that only get used by userspace don't generally show up in /proc/cpuinfo. KVM is kinda a weird case. The kernel is making the feature available to guests, but it's not _using_ it in any meaningful way. To me, this seems much more akin to the features that are just available to userspace than something that the kernel is truly using. Also, these feature names are just long and ugly, and the "flags" line is already a human-*un*readable mess. I think we should just leave them out.