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=-7.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 717F9C433DB for ; Fri, 5 Feb 2021 11:05:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C3FC64E34 for ; Fri, 5 Feb 2021 11:05:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231263AbhBELEi (ORCPT ); Fri, 5 Feb 2021 06:04:38 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:47691 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231949AbhBELCa (ORCPT ); Fri, 5 Feb 2021 06:02:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612522864; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hlQHxvz68herj6uUlAqo6cNNlISG8mBPX3iyJA1YfgY=; b=U2R7dq0veCLLFAVwqOxvVea3BPvYdvokhPTfULuAhI6A4XeySy63DjAVyJcnCbRVrkR6zX Wpn5bRZyNzi+n8f6hFmcNpvvdV3YNIGn1/hNYjea7bwdvNBMVohSoXQmT8Fiv/NzsjcCn4 xvWmheoU8pNCX+B64VpCHF2LcEveh0E= Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-311-1__g6rOUPPGlwnW1Za16rQ-1; Fri, 05 Feb 2021 06:01:02 -0500 X-MC-Unique: 1__g6rOUPPGlwnW1Za16rQ-1 Received: by mail-ed1-f69.google.com with SMTP id p18so6753401edr.20 for ; Fri, 05 Feb 2021 03:01:02 -0800 (PST) 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=hlQHxvz68herj6uUlAqo6cNNlISG8mBPX3iyJA1YfgY=; b=CbwhBSaVtCNPu0+2TL7s85Mt0kkkUtcZ0vUTg0MzKcPWzEVSOepGvpxVoeCVFGv8b9 5W0ErOPIlIwbAPNJey3/1PVOixVmfdO3XXalWRcuokUBWOp/lyNRC4py2Pwq3Hf7RTiZ khjSgPpUbSWCdFpPvSZVdZpTmrojo9K+pEmQiJpiOPsTKTLbcEYfq/jXRrQG9cU+3HQA PSY5fiAGPXIcEEodw5hWG6vTOeeJGejKX5Bv5YBEiDQVn5izKEjIiPIdn7qwzNbTdl0d TQjzG4qAelBWNpzoVmFFMuq+/H5ZxOfjz7HvkcT7dvatOORuhMwHuq/KP15plvb9GF4U XC0w== X-Gm-Message-State: AOAM531ZJGQ44T4h4OcoboV3ILcd1wOmnYeSUhrNHxA0sqGNEEtXl8sV AFvHBluZ4Rz66LtUP9QybBLnmbY3tgH6U9Ye/vW19/rpq0e0bmXxBG2TERVQwuIUFhOMF3tOhYf sdID7woqcPYdi X-Received: by 2002:a17:906:d84:: with SMTP id m4mr3483453eji.437.1612522861733; Fri, 05 Feb 2021 03:01:01 -0800 (PST) X-Google-Smtp-Source: ABdhPJy4F1t/R+DPSOQFVqV3fjaYushABxmKmxDzt7PERmONeplKqUD5cGkaLMtwig78BxPe+5fXxw== X-Received: by 2002:a17:906:d84:: with SMTP id m4mr3483425eji.437.1612522861540; Fri, 05 Feb 2021 03:01:01 -0800 (PST) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id x25sm3802377edv.65.2021.02.05.03.00.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 05 Feb 2021 03:01:00 -0800 (PST) Subject: Re: [PATCH v2 4/4] KVM: x86: Expose Architectural LBR CPUID and its XSAVES bit To: "Xu, Like" , Sean Christopherson Cc: Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Like Xu References: <20210203135714.318356-1-like.xu@linux.intel.com> <20210203135714.318356-5-like.xu@linux.intel.com> <8321d54b-173b-722b-ddce-df2f9bd7abc4@redhat.com> <219d869b-0eeb-9e52-ea99-3444c6ab16a3@intel.com> From: Paolo Bonzini Message-ID: <7698fd6c-94da-e352-193f-e09e002a8961@redhat.com> Date: Fri, 5 Feb 2021 12:00:59 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 05/02/21 09:16, Xu, Like wrote: > Hi Paolo, > > I am wondering if it is acceptable for you to > review the minor Architecture LBR patch set without XSAVES for v5.12 ? > > As far as I know, the guest Arch LBR  can still work without XSAVES > support. I dopn't think it can work. You could have two guests on the same physical CPU and the MSRs would be corrupted if the guests write to the MSR but they do not enable the LBRs. Paolo