Received: by 2002:a05:6a10:9848:0:0:0:0 with SMTP id x8csp3909114pxf; Mon, 29 Mar 2021 15:14:58 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwRtDaUjOvFwlnx0EDONAQRXEulStA8z/cT19JztGHPDNH65Pyi5bYuLgqMXOdYR7Avbn+0 X-Received: by 2002:a05:6402:4241:: with SMTP id g1mr31065501edb.331.1617056097938; Mon, 29 Mar 2021 15:14:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1617056097; cv=none; d=google.com; s=arc-20160816; b=X7dm9v9BzsEqj491XOC7qXygKZZO5rCrqYITae63yYV32WMsFzE7wLvHw4FwV2XK5d CBkOwnf77fpaJwKi1IaUSYD8xh+Tiu1a4B/kojMUN1jThgpSyFIjQPEEOvefT/55A8eK efJdrPhYJsjx56F+mw+LztD85jmqUWJUxspw91vYSpupOO1NUlOI7Ty4jB6Uu9SU5gBM 1iLgP1CtmOVxzMYswL+qFlRoR4Dl5nAjXW9sK9rhGtXNePf4vZ+6kZhDKF/mIYUXslNu tpOLhOAD4/J6eniPQ9XPU2HWOEsGE1TMx8YUILhk/vyyCpFevR7aTS7AqSZ9d6pL6VNE 7OSA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence: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=z6xHU2zUDJNiJRM5BA+dcI/sWzO30Cc6jJSpigHvT20=; b=zLfNw+X0zFdfUS/rj5N9Bg7rDcurknpKIG/P6tIVzJGNYMbkuUcfTGW5tMpAQB96zZ GklSykz3ZCe/lPz0UJa1LLUZJ9PrQDZ9cODXmbpKNDjid8jP45eV3Ql+nyJLP50aSkFA xxE8WFwikAPCmgo8dwRw+6IbU7aH8zatnKNwPjZY3rfVYJJeP3by7ETuQiqdtwZ3xlOl VAKSVgV4+IcjM+bE45oC7PaZcvFI+Rh/1wOMtFLODovgxjnQl8kjNfWN1bEjW8Y0i5xs vhZQc+7T2qHZ814OxdFpqHXE/gj0ITCtd4WmdCXy0VlixuOtdfOKo6BHAQuMP/5REsvm 24Qg== 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 ly21si13864411ejb.128.2021.03.29.15.14.34; Mon, 29 Mar 2021 15:14:57 -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 S231246AbhC2WNI (ORCPT + 99 others); Mon, 29 Mar 2021 18:13:08 -0400 Received: from mga04.intel.com ([192.55.52.120]:64343 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230329AbhC2WM6 (ORCPT ); Mon, 29 Mar 2021 18:12:58 -0400 IronPort-SDR: QJUx8o6ef5kaDmFo2TXg16eaqLFvmB4jOh7JdXoiAOXzkgr95Sa7T4Grq0PHDS8+QlP1wBCbC0 Sm8ZPNNRPRpw== X-IronPort-AV: E=McAfee;i="6000,8403,9938"; a="189388133" X-IronPort-AV: E=Sophos;i="5.81,289,1610438400"; d="scan'208";a="189388133" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Mar 2021 15:12:58 -0700 IronPort-SDR: W3mNV5rWHpz6yPpF4v74lBWjQFBVOOrRySejGHs4AlyN65T1TeESoZYnM1Bfc+W8LetE5Azinh xE2c+4EEW9Pg== X-IronPort-AV: E=Sophos;i="5.81,289,1610438400"; d="scan'208";a="411297203" Received: from jmwolcot-mobl.amr.corp.intel.com (HELO [10.209.158.84]) ([10.209.158.84]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Mar 2021 15:12:57 -0700 Subject: Re: [PATCH v2 1/1] x86/tdx: Handle MWAIT, MONITOR and WBINVD To: "Kuppuswamy, Sathyanarayanan" , Peter Zijlstra , Andy Lutomirski Cc: Andi Kleen , Kirill Shutemov , Kuppuswamy Sathyanarayanan , Dan Williams , Raj Ashok , Sean Christopherson , linux-kernel@vger.kernel.org References: <91C0F6F1-B8C3-4130-B903-C63CD4B87F3F@amacapital.net> <498f078c-5196-a608-7f1a-8425ff056135@intel.com> <8e02ce39-f672-e652-b314-418b7ec5f52a@linux.intel.com> 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: <0356a84a-765e-b20b-2efd-c5d94fc2347e@intel.com> Date: Mon, 29 Mar 2021 15:12:57 -0700 User-Agent: Mozilla/5.0 (X11; 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 3/29/21 3:09 PM, Kuppuswamy, Sathyanarayanan wrote: >>>>> +    case EXIT_REASON_MWAIT_INSTRUCTION: >>>>> +        /* MWAIT is supressed, not supposed to reach here. */ >>>>> +        WARN(1, "MWAIT unexpected #VE Exception\n"); >>>>> +        return -EFAULT; >>>> >>>> How is MWAIT "supppressed"? >>> I am clearing the MWAIT feature flag in early init code. We should also >>> disable this feature in firmware. >>> setup_clear_cpu_cap(X86_FEATURE_MWAIT); >> >> I'd be more explicit about that.  Maybe even reference the code that >> clears the X86_FEATURE. > This change is part of the same patch. Right, but if someone goes and looks at the switch() statement in 10 years is it going to be obvious how MWAIT was "suppressed"?