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[23.128.96.18]) by mx.google.com with ESMTP id kk8si2561643ejc.404.2021.03.31.15.14.17; Wed, 31 Mar 2021 15:14:40 -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 S232585AbhCaWMF (ORCPT + 99 others); Wed, 31 Mar 2021 18:12:05 -0400 Received: from mga04.intel.com ([192.55.52.120]:52036 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229787AbhCaWL7 (ORCPT ); Wed, 31 Mar 2021 18:11:59 -0400 IronPort-SDR: 2zR3dTDCXYto8bp9C1C/RXDBx/T68F3WuR2Qk3TC1aIqBRIzDoQr8effLKQ37WFW/OBE87GhMl R55M1/17MOmw== X-IronPort-AV: E=McAfee;i="6000,8403,9940"; a="189869170" X-IronPort-AV: E=Sophos;i="5.81,295,1610438400"; d="scan'208";a="189869170" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Mar 2021 15:11:58 -0700 IronPort-SDR: N30Tvd6mL2JKMavIC8UXiVqwB/LVBQ8TLvIaN0u+So0DHsmwYzbL3do0kqqQoVbZy42iTzz7iM V8r65CZJ4KYg== X-IronPort-AV: E=Sophos;i="5.81,295,1610438400"; d="scan'208";a="418877305" Received: from algolden-mobl1.amr.corp.intel.com (HELO [10.209.172.7]) ([10.209.172.7]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Mar 2021 15:11:58 -0700 Subject: Re: [PATCH v4 1/1] x86/tdx: Handle MWAIT, MONITOR and WBINVD To: Sean Christopherson Cc: Kuppuswamy Sathyanarayanan , Peter Zijlstra , Andy Lutomirski , Andi Kleen , Kirill Shutemov , Kuppuswamy Sathyanarayanan , Dan Williams , Raj Ashok , linux-kernel@vger.kernel.org References: <2FE32855-EA5D-44E4-AACC-25E9B1476547@amacapital.net> <5d961c25-3dee-4a5d-4bba-a97d157a5a49@intel.com> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/31/21 3:06 PM, Sean Christopherson wrote: > I've no objection to a nice message in the #VE handler. What I'm objecting to > is sanity checking the CPUID model provided by the TDX module. If we don't > trust the TDX module to honor the spec, then there are a huge pile of things > that are far higher priority than MONITOR/MWAIT. In other words: Don't muck with CPUID or the X86_FEATURE at all. Don't check it to comply with the spec. If something doesn't comply, we'll get a #VE at *SOME* point. We don't need to do belt-and-suspenders programming here. That sounds sane to me.