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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 18AD2C43218 for ; Tue, 11 Jun 2019 11:10:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E2DDA2080A for ; Tue, 11 Jun 2019 11:10:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388956AbfFKLKA (ORCPT ); Tue, 11 Jun 2019 07:10:00 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:37651 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388447AbfFKLJ7 (ORCPT ); Tue, 11 Jun 2019 07:09:59 -0400 Received: by mail-wr1-f66.google.com with SMTP id v14so12535870wrr.4 for ; Tue, 11 Jun 2019 04:09:59 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=Ewq00r0CEEYLXioP30O1q2BeCLR2SfDQByxI3ASmz30=; b=ar+FsVde5zUpYyHd+9ZM/eClx91VKz1DWgmNCdJLYqlf2HBGgM6bCM2vSPLruvU6aE FpxjYWElgMwV45K0uI06QS/HPlVd/ol+Rig4piJv/wC1OJztSX9NA8qo8vTnPBN5RvZ4 CBKV9P6WWKW3dPuumYfzzQdx35L/9ULYNuTIQ+AvHEMgjOywtrHThgmV8N5nzN/7Lup7 MXoyd/3WvD9/hv0rGismCeextTwUDHwt/vKss60cCb1BgOe8r51hIiSCYA7k6PmJRVo+ EzdJilP6k+L5DSHlKLrtxmbw3wFqEUgSlRBVYqMVEgQ0T2voVxAcx/I1sRjDuL1FmE3g Pj1Q== X-Gm-Message-State: APjAAAXPANpfY27FrGx83dekYlROdvW2WsILJ71s6bt43RHOEpUwHr1y aKX9UFTAQGonfzZ+MveY2vWnsg== X-Google-Smtp-Source: APXvYqzN/haxCNxgeICKR52OC0EvsGr/RwWKjb1vCrA8a/DvAOMqDb3jb86+FmbFRNs7K9cItb7HhA== X-Received: by 2002:a5d:6b49:: with SMTP id x9mr33023295wrw.170.1560251398314; Tue, 11 Jun 2019 04:09:58 -0700 (PDT) Received: from [192.168.10.150] ([93.56.166.5]) by smtp.gmail.com with ESMTPSA id c16sm11726088wrr.53.2019.06.11.04.09.54 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Tue, 11 Jun 2019 04:09:57 -0700 (PDT) Subject: Re: [PATCH v2 2/3] KVM: X86: Provide a capability to disable cstate msr read intercepts To: Wanpeng Li Cc: LKML , kvm , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Sean Christopherson , Liran Alon References: <1558418814-6822-1-git-send-email-wanpengli@tencent.com> <1558418814-6822-2-git-send-email-wanpengli@tencent.com> <627e4189-3709-1fb2-a9bc-f1a577712fe0@redhat.com> From: Paolo Bonzini Message-ID: Date: Tue, 11 Jun 2019 13:09:53 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: 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 11/06/19 09:38, Wanpeng Li wrote: > MSR_CORE_C1_RES is unreadable except for ATOM platform, so I think we > can avoid the complex logic to handle C1 now. :) I disagree. Linux uses it on all platforms is available, and virtual machines that don't pass mwait through _only_ have C1, so it would be less useful to have deep C-state residency MSRs and not C1 residency. But turbostat can get the information from sysfs, so what are these MSRs used for? Paolo