From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-6.0 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id ACC287D2EF for ; Wed, 29 May 2019 01:28:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725847AbfE2B2X (ORCPT ); Tue, 28 May 2019 21:28:23 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:35452 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725830AbfE2B2X (ORCPT ); Tue, 28 May 2019 21:28:23 -0400 Received: by mail-wr1-f65.google.com with SMTP id m3so467537wrv.2 for ; Tue, 28 May 2019 18:28:22 -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=Zy4dt0/WsQ2pPQWde6zfELpEkgD8cGRU5zkaONVLf7w=; b=TTasZ7FhUHJRW67E/WnmTlUTlgyfDE5feIfSPAcNeWM5629ZtxmVGbAt6DYJWGJQiQ 5KiHr4y44vqCjWMDhkkFgrinqOS1P0HaxeoKijKZGeNmrWrp9Hs0sBXJUr7/DIrN2+GE m/yc6SAmRqiaqyivab0mhpUbkOUjBHPlyk36JJwl/QTDOhHDFvo1+ASGWKm/3q5kBuqx PMFz4L4vZxZCyfUhWKkVHXC9154rzOlZ2Fn3tNadJhUOdc+/EocN/JmTYG/hlPnu8raE mWYYZsgl2X44ePMLgFN4Z6fGXHmYIGcT10zRgWHLbf9twifsmf46kZCHllptGaaWly2i kSvQ== X-Gm-Message-State: APjAAAV2p/55mj+aoUCeKku2HGS1713DGtxoKN2FKGIByJemtIZuIVwd GKHd85Ra/aKH4QtshsK3QmOfEw== X-Google-Smtp-Source: APXvYqwZYgBbYcOXL1jluAbtyuzMdx9moyE1uHZ1h1H51iIfrMrheEe0qRvL24XxCKchdTyl5TIvIA== X-Received: by 2002:adf:b64b:: with SMTP id i11mr7328142wre.205.1559093301578; Tue, 28 May 2019 18:28:21 -0700 (PDT) Received: from [192.168.10.150] ([93.56.166.5]) by smtp.gmail.com with ESMTPSA id r16sm11765117wrj.13.2019.05.28.18.28.20 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 May 2019 18:28:21 -0700 (PDT) Subject: Re: [PATCH v2 3/3] KVM: vmx: handle vm-exit for UMWAIT and TPAUSE To: Tao Xu , rkrcmar@redhat.com, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, sean.j.christopherson@intel.com Cc: x86@kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, jingqi.liu@intel.com References: <20190524075637.29496-1-tao3.xu@intel.com> <20190524075637.29496-4-tao3.xu@intel.com> From: Paolo Bonzini Message-ID: Date: Wed, 29 May 2019 03:28:19 +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: <20190524075637.29496-4-tao3.xu@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 24/05/19 09:56, Tao Xu wrote: > As the latest Intel 64 and IA-32 Architectures Software Developer's > Manual, UMWAIT and TPAUSE instructions cause a VM exit if the > “RDTSC exiting” and “enable user wait and pause” VM-execution controls > are both 1. > > This patch is to handle the vm-exit for UMWAIT and TPAUSE as invalid_op. KVM never enables RDTSC exiting, so this is not necessary. Paolo