Received: by 10.213.65.68 with SMTP id h4csp927832imn; Sun, 25 Mar 2018 18:23:22 -0700 (PDT) X-Google-Smtp-Source: AG47ELs2eNNCEE/DQqKs8U7HBAiv+WmAluBQJ+KqhhY2N6UP/UPytJKcaM1FqWfpO1J1ilzsu6nD X-Received: by 10.99.97.149 with SMTP id v143mr27084285pgb.319.1522027402171; Sun, 25 Mar 2018 18:23:22 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1522027402; cv=none; d=google.com; s=arc-20160816; b=uvzM3tKNEx/WQN0s7Ga9CZkBKJcNm9lciHQ/ngCmJQIiIHZKXT3pXaCgnsaV7JpxMQ 2fBtzOg7LcqdyjpQvCsyUcmWBPslEsU2lxGWI8Jy3BQA7DekrhjiRP7OCseMv8prCCHg kTvuQnSfO9oVuKXHwEvmM0tBwXcEBEEuPUeiM4Z8488/582jG3XxIx+zukNge9f0cm4E vFDp4o7ZXjndQpQVnzXuWaPgRXZDVPahYnDgSZsuT+Pg5m7D1qNq+oQoMgzIr/vmxeP0 7aJrVv7DEUTIJDhurmUvlvTJj6sdmoALtG6OpIpxf6u8A3vpew5wf+9t0J4oxhQMqLOf eiOw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject:arc-authentication-results; bh=pEJ2kwSjWnvYVIY6Sln3IRTYq+kq1A61fP365nEOZjk=; b=drZxWwDgBTECVa0xutCFf/YP/ejN9JnOl5A2AzOBQbGXmbHNAyCt5efShk4h6zpubP jeSQPTLMQ1gGR35P63rhsTCQr0+1XdCzplDHFN07w2OqCslQVKMfL8K/BSppOorwHFAB +WULIrjecyV2NccqbckYZQ46NG9+Y4gPFvBIncGdePMSo+AS8+C2toDCohaqNLAp+ZdI ka8gOCmLV6i9B90vpnG8nYDEhHdUii4Kv7zM4FIwJIw6HioIlrV+H7HdEhvzHl+RIFM4 m7NdSJV11TbLWFc5fxmWTL6uwwnq0LJRzIIN+5lRv6yjR+Rv2LaIfXYIEAS4Jx4wHZug PdZg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id p26-v6si13879864pli.534.2018.03.25.18.23.07; Sun, 25 Mar 2018 18:23:22 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751087AbeCZBWP (ORCPT + 99 others); Sun, 25 Mar 2018 21:22:15 -0400 Received: from terminus.zytor.com ([198.137.202.136]:49605 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750832AbeCZBWO (ORCPT ); Sun, 25 Mar 2018 21:22:14 -0400 Received: from carbon-x1.hos.anvin.org (c-24-5-245-234.hsd1.ca.comcast.net [24.5.245.234] (may be forged)) (authenticated bits=0) by mail.zytor.com (8.15.2/8.15.2) with ESMTPSA id w2Q1Leje059999 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO); Sun, 25 Mar 2018 18:21:40 -0700 Subject: Re: [PATCH v3 1/2] x86, msr: allow rdmsr_safe_on_cpu() to schedule To: Borislav Petkov , Eric Dumazet Cc: Ingo Molnar , Eric Dumazet , x86 , lkml , Thomas Gleixner , Ingo Molnar , Hugh Dickins , Peter Zijlstra References: <20180323215818.127774-1-edumazet@google.com> <20180324080946.3db4xdkl5i6jx2rc@gmail.com> <336355a3-c11d-44fc-0642-671670980ac0@gmail.com> <20180325141242.GC21878@pd.tnic> From: "H. Peter Anvin" Message-ID: <69c614fb-5c3d-b1fb-99be-15dc8775483c@zytor.com> Date: Sun, 25 Mar 2018 18:21:34 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180325141242.GC21878@pd.tnic> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/25/18 07:12, Borislav Petkov wrote: > > So I'm wondering if poking at the hardware like that is a really optimal > design. Maybe it would be cleaner if the OS would provide properly > abstracted sysfs interfaces instead of raw MSRs. For a couple of > reasons: > It's most definitely not. -hpa