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 AE24BC433F5 for ; Tue, 11 Jan 2022 06:24:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348156AbiAKGY3 (ORCPT ); Tue, 11 Jan 2022 01:24:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58504 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232725AbiAKGY2 (ORCPT ); Tue, 11 Jan 2022 01:24:28 -0500 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0184CC06173F; Mon, 10 Jan 2022 22:24:28 -0800 (PST) Received: by mail-pj1-x102a.google.com with SMTP id o3so5311089pjs.1; Mon, 10 Jan 2022 22:24:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:content-language:from:to:cc :references:organization:subject:in-reply-to :content-transfer-encoding; bh=3AbMTJp+scsKh0PggMwmUYkYlbPH3KwJj4i9E8ycZus=; b=SjEVfTOPNfLbvyaLoZBhlW1cPZ8y3zwopX3SVU4XBsORjJcIQGHCjq5ilXJtz9MiU8 I3y8QKRPdLSarRP9v2A+0MX9za9oiWj1/r4DT0OrvGTdsaomGd6/cpzHtJrl6YWYP4l5 vm/VZJAQfAoWtkMld1EG5dFbxTAsti7osbFCqLU/+4ZEysy7HUEpv/1YW1OVwHX2pTNO Thx89yf4AocS7nBta1afPnifDkRHWJ31suQq1zg+y/nRPLDB8Ybq9vxuSGL5MsYiKLdf llQiQpUipB1Tk3KZ9uE659S2Azmn/wFLvD43FIG/vKFmt2a0a884cpueCVv0579uPkTT YV0g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent :content-language:from:to:cc:references:organization:subject :in-reply-to:content-transfer-encoding; bh=3AbMTJp+scsKh0PggMwmUYkYlbPH3KwJj4i9E8ycZus=; b=jlRnRMNm1b7m908XOWlDPgjqXgY18y50CrV0W9Vd6mh5cSWBrd1qVHJlUxwy80ytYv Xp16uVCf8GYXqkk46E19yzaxA7EzqeABDC7QN86PYucr1zxahtax4l3+XvURP8x2aC/U HwjfLxAyRz7kQtXoPItJlE7RclLvMZKZsKh6ifnAE3uiP6aWv7jIz24oMCUGT3HMb5Ey 2ntLlvfRuaTaCjvNm2vIgerKI439+nSJyiHEmquwKTxXI4KIHHNzd/56GdL/Ge5eQuNv 3pqa4rsQvdl/TZFIe/h7gCpeIR60209IzMcs1V7d8DmweUqJDVyzBPzJxFDGy/ihmPhV hN8Q== X-Gm-Message-State: AOAM533OIeAFvYGr7aUNiEK21ZXAu31eomgvJrm9D9B3T2nEoe6j0tar mho0HKtOAd4x+EN1po0Ozy0= X-Google-Smtp-Source: ABdhPJyMOI8YNb/db8KbqDSWdvKtuKA21LtGDqvTisPX8uzizPF3zy6gNnhenH5IgGaC9okRtFNRIA== X-Received: by 2002:a17:902:e752:b0:14a:4743:be6e with SMTP id p18-20020a170902e75200b0014a4743be6emr3058956plf.122.1641882267503; Mon, 10 Jan 2022 22:24:27 -0800 (PST) Received: from [192.168.255.10] ([103.7.29.32]) by smtp.gmail.com with ESMTPSA id 20sm4390445pge.68.2022.01.10.22.24.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 10 Jan 2022 22:24:27 -0800 (PST) Message-ID: Date: Tue, 11 Jan 2022 14:24:18 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.4.1 Content-Language: en-US From: Like Xu To: Sean Christopherson , Paolo Bonzini Cc: Jim Mattson , Wanpeng Li , Vitaly Kuznetsov , Joerg Roedel , x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org References: <20220110034747.30498-1-likexu@tencent.com> <80b40829-0d25-eb84-7bd7-f21685daeb20@gmail.com> Organization: Tencent Subject: Re: [PATCH v2] KVM: x86/pt: Ignore all unknown Intel PT capabilities In-Reply-To: <80b40829-0d25-eb84-7bd7-f21685daeb20@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/1/2022 12:20 pm, Like Xu wrote: >> And is there any possibility of a malicious user/guest using features to cause >> problems in the host?  I.e. does KVM need to enforce that the guest can't enable >> any unsupported features? > > If a user space is set up with features not supported by KVM, it owns the risk > itself. I seem to have misunderstood it. KVM should prevent and stop any malicious guest from destroying other parts on the host, is this the right direction ? > > AFAI, the guest Intel PT introduces a great attack interface for the host and > we only use the guest supported PT features in a highly trusted environment. > > I agree that more uncertainty and fixes can be triggered in the security motive, > not expecting too much from this patch. :D