Received: by 2002:a25:e74b:0:0:0:0:0 with SMTP id e72csp2050954ybh; Tue, 14 Jul 2020 14:23:45 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxt7c1db50eYGOEzFTSzd9Fp3Jzj/5PAZI4livnRhQqubpZzM2qmlNe9QAc4tFcfnlnmbaA X-Received: by 2002:a05:6402:1605:: with SMTP id f5mr6955439edv.8.1594761825759; Tue, 14 Jul 2020 14:23:45 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1594761825; cv=none; d=google.com; s=arc-20160816; b=sNH3O/o+APp4ahmYS5gNmc44bJW+5KjTbcn3JH0PrmBNe6AfvB7w17wxAdwjNmX4j8 J454kwZaSW4mBZTP6h2AbLyUczJVDzax3IvZuic1bV/aF4VxxwXoTuC8XxI8dH2CeE7h YXE+HNWf8zVVea5GptEteth+vTmVot1sj18gV2MUCuuHKkMPvVgPKsqhjmsbPwXrLmJ2 YwDYG60trwP0yK1qQlz7Ex9DvHFLJ0brZkIF98DAgk3DLlHhcHQ9a/RkjOJXNPwVj68B MF4beLKeNs+9PM7rZRajG4HM19JBhDAeLkSH3wOhFWiUbVL5I1jZbMAHu+bwaUjz2ewA QD+Q== 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:autocrypt:from:references:cc:to:subject:ironport-sdr :ironport-sdr; bh=7klGSSRJxOvk3Hh746gDynXKICXodQtP3gT2jlsNgbY=; b=F1YSgBhodbWRBLkU2YIDf5vJ54eJpFHwWD6a1v4dkzxN2SFQ2EQ3nSw179YjAmk0Yh GaHjgyEo7VTTwMyCo72NBv1fDnHyOZRUmRSorta7j+5PsCGNZwwBJJvpUouszM4RhwTO Eo51vI1C8HyVZH7aRC1P6b8plB7WMNsrPTR8Zy+vynqBE66UP8zKEVswpsrhs7pZDOHc q5Zp4wBUBjQQuw0ninLXADoNQaSiKTLCXVQ0nfD7x6JmXqFs69j1ZJoqIplu60FTi0VN M8GMvLFmA85tESl3S2v5nCpWhqHvGL60AeswsfUdN6KnKAFjI8XG/AWPBnlbY/7kDVEl O1NQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id lz15si11108423ejb.406.2020.07.14.14.23.19; Tue, 14 Jul 2020 14:23:45 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728153AbgGNVVG (ORCPT + 99 others); Tue, 14 Jul 2020 17:21:06 -0400 Received: from mga04.intel.com ([192.55.52.120]:9623 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726446AbgGNVVG (ORCPT ); Tue, 14 Jul 2020 17:21:06 -0400 IronPort-SDR: fenFSfNQSgG9WS28fs+PQlCF5Au78wb2LSAdXxk6zAqoNpDh6XTecnt0uLhw87nOgAPgC/BIUb bzb9Enxqx2Rg== X-IronPort-AV: E=McAfee;i="6000,8403,9682"; a="146539647" X-IronPort-AV: E=Sophos;i="5.75,352,1589266800"; d="scan'208";a="146539647" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jul 2020 14:21:04 -0700 IronPort-SDR: gBvhmRoYJoxT7k39MOhf5H7gydOnQ21Hct6f9tvw9mmsVBO82OshZnuQYJDUcX4SIoFineWgFn e3u4xCPShJrw== X-IronPort-AV: E=Sophos;i="5.75,352,1589266800"; d="scan'208";a="459835098" Received: from calinapo-mobl.amr.corp.intel.com (HELO [10.255.6.204]) ([10.255.6.204]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jul 2020 14:21:00 -0700 Subject: Re: [PATCH] x86/bugs/multihit: Fix mitigation reporting when KVM is not in use To: Pawan Gupta Cc: Sean Christopherson , Borislav Petkov , Thomas Gleixner , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Tony Luck , "Gomez Iglesias, Antonio" , Andy Lutomirski , Peter Zijlstra , Fenghua Yu , Dave Hansen , Vincenzo Frascino , Josh Poimboeuf , Anthony Steinhauser , Mike Rapoport , Mark Gross , Waiman Long , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Jonathan Corbet References: <267631f4db4fd7e9f7ca789c2efaeab44103f68e.1594689154.git.pawan.kumar.gupta@linux.intel.com> <20200714014540.GH29725@linux.intel.com> <099d6985-9e9f-1d9f-7098-58a9e26e4450@intel.com> <20200714191759.GA7116@guptapadev.amr> <20200714210442.GA10488@guptapadev.amr> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; keydata= xsFNBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC oAiUXvGAOxPDsB/P6UEOISPpLl5IuYsSwAeZGkdQ5g6m1xq7AlDJQZddhr/1DC/nMVa/2BoY 2UnKuZuSBu7lgOE193+7Uks3416N2hTkyKUSNkduyoZ9F5twiBhxPJwPtn/wnch6n5RsoXsb ygOEDxLEsSk/7eyFycjE+btUtAWZtx+HseyaGfqkZK0Z9bT1lsaHecmB203xShwCPT49Blxz VOab8668QpaEOdLGhtvrVYVK7x4skyT3nGWcgDCl5/Vp3TWA4K+IofwvXzX2ON/Mj7aQwf5W iC+3nWC7q0uxKwwsddJ0Nu+dpA/UORQWa1NiAftEoSpk5+nUUi0WE+5DRm0H+TXKBWMGNCFn c6+EKg5zQaa8KqymHcOrSXNPmzJuXvDQ8uj2J8XuzCZfK4uy1+YdIr0yyEMI7mdh4KX50LO1 pmowEqDh7dLShTOif/7UtQYrzYq9cPnjU2ZW4qd5Qz2joSGTG9eCXLz5PRe5SqHxv6ljk8mb ApNuY7bOXO/A7T2j5RwXIlcmssqIjBcxsRRoIbpCwWWGjkYjzYCjgsNFL6rt4OL11OUF37wL QcTl7fbCGv53KfKPdYD5hcbguLKi/aCccJK18ZwNjFhqr4MliQARAQABzShEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gPGRhdmVAc3I3MS5uZXQ+wsF7BBMBAgAlAhsDBgsJCAcDAgYVCAIJ CgsEFgIDAQIeAQIXgAUCTo3k0QIZAQAKCRBoNZUwcMmSsMO2D/421Xg8pimb9mPzM5N7khT0 2MCnaGssU1T59YPE25kYdx2HntwdO0JA27Wn9xx5zYijOe6B21ufrvsyv42auCO85+oFJWfE K2R/IpLle09GDx5tcEmMAHX6KSxpHmGuJmUPibHVbfep2aCh9lKaDqQR07gXXWK5/yU1Dx0r VVFRaHTasp9fZ9AmY4K9/BSA3VkQ8v3OrxNty3OdsrmTTzO91YszpdbjjEFZK53zXy6tUD2d e1i0kBBS6NLAAsqEtneplz88T/v7MpLmpY30N9gQU3QyRC50jJ7LU9RazMjUQY1WohVsR56d ORqFxS8ChhyJs7BI34vQusYHDTp6PnZHUppb9WIzjeWlC7Jc8lSBDlEWodmqQQgp5+6AfhTD kDv1a+W5+ncq+Uo63WHRiCPuyt4di4/0zo28RVcjtzlGBZtmz2EIC3vUfmoZbO/Gn6EKbYAn rzz3iU/JWV8DwQ+sZSGu0HmvYMt6t5SmqWQo/hyHtA7uF5Wxtu1lCgolSQw4t49ZuOyOnQi5 f8R3nE7lpVCSF1TT+h8kMvFPv3VG7KunyjHr3sEptYxQs4VRxqeirSuyBv1TyxT+LdTm6j4a mulOWf+YtFRAgIYyyN5YOepDEBv4LUM8Tz98lZiNMlFyRMNrsLV6Pv6SxhrMxbT6TNVS5D+6 UorTLotDZKp5+M7BTQRUY85qARAAsgMW71BIXRgxjYNCYQ3Xs8k3TfAvQRbHccky50h99TUY sqdULbsb3KhmY29raw1bgmyM0a4DGS1YKN7qazCDsdQlxIJp9t2YYdBKXVRzPCCsfWe1dK/q 66UVhRPP8EGZ4CmFYuPTxqGY+dGRInxCeap/xzbKdvmPm01Iw3YFjAE4PQ4hTMr/H76KoDbD cq62U50oKC83ca/PRRh2QqEqACvIH4BR7jueAZSPEDnzwxvVgzyeuhwqHY05QRK/wsKuhq7s UuYtmN92Fasbxbw2tbVLZfoidklikvZAmotg0dwcFTjSRGEg0Gr3p/xBzJWNavFZZ95Rj7Et db0lCt0HDSY5q4GMR+SrFbH+jzUY/ZqfGdZCBqo0cdPPp58krVgtIGR+ja2Mkva6ah94/oQN lnCOw3udS+Eb/aRcM6detZr7XOngvxsWolBrhwTQFT9D2NH6ryAuvKd6yyAFt3/e7r+HHtkU kOy27D7IpjngqP+b4EumELI/NxPgIqT69PQmo9IZaI/oRaKorYnDaZrMXViqDrFdD37XELwQ gmLoSm2VfbOYY7fap/AhPOgOYOSqg3/Nxcapv71yoBzRRxOc4FxmZ65mn+q3rEM27yRztBW9 AnCKIc66T2i92HqXCw6AgoBJRjBkI3QnEkPgohQkZdAb8o9WGVKpfmZKbYBo4pEAEQEAAcLB XwQYAQIACQUCVGPOagIbDAAKCRBoNZUwcMmSsJeCEACCh7P/aaOLKWQxcnw47p4phIVR6pVL e4IEdR7Jf7ZL00s3vKSNT+nRqdl1ugJx9Ymsp8kXKMk9GSfmZpuMQB9c6io1qZc6nW/3TtvK pNGz7KPPtaDzvKA4S5tfrWPnDr7n15AU5vsIZvgMjU42gkbemkjJwP0B1RkifIK60yQqAAlT YZ14P0dIPdIPIlfEPiAWcg5BtLQU4Wg3cNQdpWrCJ1E3m/RIlXy/2Y3YOVVohfSy+4kvvYU3 lXUdPb04UPw4VWwjcVZPg7cgR7Izion61bGHqVqURgSALt2yvHl7cr68NYoFkzbNsGsye9ft M9ozM23JSgMkRylPSXTeh5JIK9pz2+etco3AfLCKtaRVysjvpysukmWMTrx8QnI5Nn5MOlJj 1Ov4/50JY9pXzgIDVSrgy6LYSMc4vKZ3QfCY7ipLRORyalFDF3j5AGCMRENJjHPD6O7bl3Xo 4DzMID+8eucbXxKiNEbs21IqBZbbKdY1GkcEGTE7AnkA3Y6YB7I/j9mQ3hCgm5muJuhM/2Fr OPsw5tV/LmQ5GXH0JQ/TZXWygyRFyyI2FqNTx4WHqUn3yFj8rwTAU1tluRUYyeLy0ayUlKBH ybj0N71vWO936MqP6haFERzuPAIpxj2ezwu0xb1GjTk4ynna6h5GjnKgdfOWoRtoWndMZxbA z5cecg== Message-ID: Date: Tue, 14 Jul 2020 14:20:59 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200714210442.GA10488@guptapadev.amr> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/14/20 2:04 PM, Pawan Gupta wrote: >> I see three inputs and four possible states (sorry for the ugly table, >> it was this or a spreadsheet :): >> >> X86_FEATURE_VMX CONFIG_KVM_* hpage split Result Reason >> N x x Not Affected No VMX >> Y N x Not affected No KVM >> Y Y Y Mitigated hpage split >> Y Y N Vulnerable > Thank you. > > Just a note... for the last 2 cases kernel wont know about "hpage split" > mitigation until KVM is loaded. So for these cases reporting at boot > will be "Vulnerable" and would change to "Mitigated" once KVM is loaded > and deploys the mitigation. This is the current behavior. That's OK with me, because it's actually pretty closely tied to reality. You are literally "vulnerable" until you've committed to a mitigation and that doesn't happen until KVM is loaded. When are we going to force kvm to be built in, again? ;)