From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C93578BE0; Thu, 4 Jul 2024 00:18:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720052308; cv=none; b=i323qMFQuwhhOMIpyMBuYD1RLU1/ApQx0CMkr3k0hdW9Dr639eHhsm6Coqli6F/Pb1juEuhd1e3hDB53fQxMj/jQw/g6pJMezsgY8pZoJmnV+xxTd4+1QBoH+9MZHEKLkVoTlFR9xXRDNdquVA97qscElxV6qUx/bpEJCD/JJYQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720052308; c=relaxed/simple; bh=i0ViCIuBLg0Rqk2p1YuOSavskC5l8UhLrUhRelfhk9I=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=J7T+d2Vb0UhIrCJ1w4Xbfcf1X4DWbbIKiM4YSTn3IB4jOiG4wjwpauJmtMTMj+qhChyC+FSv03r03WT/RwLAylZRwNsTNhs0ScaklmvhTuNDnAJMvFVcGoU1VBuR1STCEU1V9YmUaQMSctwX4WkOJCkeeBSFhxx0YchLE/F1W1w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=efdlBI++; arc=none smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="efdlBI++" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1720052307; x=1751588307; h=message-id:date:mime-version:subject:to:references:from: in-reply-to:content-transfer-encoding; bh=i0ViCIuBLg0Rqk2p1YuOSavskC5l8UhLrUhRelfhk9I=; b=efdlBI++frfop4NSelNg6SqGhQZfr9Xd+5HqfJOGzPW+F2pEdsaM+TER uC4l1S/LeVsgo7Pm84ya4Udsyn3SyqToOGTEAJFuiQOjtc+g5yl94BmU5 45sVYxVKCuRU84k+HuTSmgptWgRmmlOQ1mZveiGiyukYVuhc3kIDfKFV2 DNFpD7v5bTm+utqNrt4b24anV1Ma/3qtHVG/DhxZ6Rc85mDNGDjQSfBfn CYCGMqEeCylZazjPk7au1XvZ8DpEzc4DXWdhB4wqUYoGa1P4KkrcFc2S4 a/YhLp4bRnYAKzgVs9EiC9op/39BSpkU2tPsK7M8YQCShOCMNSyCT9C4h A==; X-CSE-ConnectionGUID: nG1vjwz3Tl2j1OPVX8unDw== X-CSE-MsgGUID: Fnh0yGrmQlu2r64qglWV8A== X-IronPort-AV: E=McAfee;i="6700,10204,11122"; a="12384908" X-IronPort-AV: E=Sophos;i="6.09,183,1716274800"; d="scan'208";a="12384908" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jul 2024 17:18:26 -0700 X-CSE-ConnectionGUID: W+rMsJLlQL657Kuuwq9o3g== X-CSE-MsgGUID: AjOX1b/PSGu8e6jcgbnIHA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,183,1716274800"; d="scan'208";a="46206031" Received: from dgramcko-desk.amr.corp.intel.com (HELO [10.124.223.221]) ([10.124.223.221]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jul 2024 17:18:25 -0700 Message-ID: <33874bf0-c115-4185-85ef-684794de3c8e@intel.com> Date: Wed, 3 Jul 2024 17:18:22 -0700 Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/2] Support userspace hypercalls for TDX To: Tim Merrifield , "Kirill A . Shutemov" , Dave Hansen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Xin Li , Ard Biesheuvel , Kai Huang , Kevin Loughlin , Thomas Zimmermann , Rick Edgecombe , Kees Cook , Mike Rapoport , Brian Gerst , linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, Ajay Kaher , Alexey Makhalov , Broadcom internal kernel review list , virtualization@lists.linux.dev, alex.james@broadcom.com, doug.covelli@broadcom.com, jeffrey.sheldon@broadcom.com References: From: Dave Hansen Content-Language: en-US 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/aCccJK18ZwNjFhqr4MliQARAQABzUVEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gKEludGVsIFdvcmsgQWRkcmVzcykgPGRhdmUuaGFuc2VuQGludGVs LmNvbT7CwXgEEwECACIFAlQ+9J0CGwMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEGg1 lTBwyZKwLZUP/0dnbhDc229u2u6WtK1s1cSd9WsflGXGagkR6liJ4um3XCfYWDHvIdkHYC1t MNcVHFBwmQkawxsYvgO8kXT3SaFZe4ISfB4K4CL2qp4JO+nJdlFUbZI7cz/Td9z8nHjMcWYF IQuTsWOLs/LBMTs+ANumibtw6UkiGVD3dfHJAOPNApjVr+M0P/lVmTeP8w0uVcd2syiaU5jB aht9CYATn+ytFGWZnBEEQFnqcibIaOrmoBLu2b3fKJEd8Jp7NHDSIdrvrMjYynmc6sZKUqH2 I1qOevaa8jUg7wlLJAWGfIqnu85kkqrVOkbNbk4TPub7VOqA6qG5GCNEIv6ZY7HLYd/vAkVY E8Plzq/NwLAuOWxvGrOl7OPuwVeR4hBDfcrNb990MFPpjGgACzAZyjdmYoMu8j3/MAEW4P0z F5+EYJAOZ+z212y1pchNNauehORXgjrNKsZwxwKpPY9qb84E3O9KYpwfATsqOoQ6tTgr+1BR CCwP712H+E9U5HJ0iibN/CDZFVPL1bRerHziuwuQuvE0qWg0+0SChFe9oq0KAwEkVs6ZDMB2 P16MieEEQ6StQRlvy2YBv80L1TMl3T90Bo1UUn6ARXEpcbFE0/aORH/jEXcRteb+vuik5UGY 5TsyLYdPur3TXm7XDBdmmyQVJjnJKYK9AQxj95KlXLVO38lczsFNBFRjzmoBEACyAxbvUEhd GDGNg0JhDdezyTdN8C9BFsdxyTLnSH31NRiyp1QtuxvcqGZjb2trDVuCbIzRrgMZLVgo3upr MIOx1CXEgmn23Zhh0EpdVHM8IKx9Z7V0r+rrpRWFE8/wQZngKYVi49PGoZj50ZEifEJ5qn/H Nsp2+Y+bTUjDdgWMATg9DiFMyv8fvoqgNsNyrrZTnSgoLzdxr89FGHZCoSoAK8gfgFHuO54B lI8QOfPDG9WDPJ66HCodjTlBEr/Cwq6GruxS5i2Y33YVqxvFvDa1tUtl+iJ2SWKS9kCai2DR 3BwVONJEYSDQaven/EHMlY1q8Vln3lGPsS11vSUK3QcNJjmrgYxH5KsVsf6PNRj9mp8Z1kIG qjRx08+nnyStWC0gZH6NrYyS9rpqH3j+hA2WcI7De51L4Rv9pFwzp161mvtc6eC/GxaiUGuH BNAVP0PY0fqvIC68p3rLIAW3f97uv4ce2RSQ7LbsPsimOeCo/5vgS6YQsj83E+AipPr09Caj 0hloj+hFoqiticNpmsxdWKoOsV0PftcQvBCCYuhKbZV9s5hjt9qn8CE86A5g5KqDf83Fxqm/ vXKgHNFHE5zgXGZnrmaf6resQzbvJHO0Fb0CcIohzrpPaL3YepcLDoCCgElGMGQjdCcSQ+Ci FCRl0Bvyj1YZUql+ZkptgGjikQARAQABwsFfBBgBAgAJBQJUY85qAhsMAAoJEGg1lTBwyZKw l4IQAIKHs/9po4spZDFyfDjunimEhVHqlUt7ggR1Hsl/tkvTSze8pI1P6dGp2XW6AnH1iayn yRcoyT0ZJ+Zmm4xAH1zqKjWplzqdb/dO28qk0bPso8+1oPO8oDhLm1+tY+cOvufXkBTm+whm +AyNTjaCRt6aSMnA/QHVGSJ8grrTJCoACVNhnXg/R0g90g8iV8Q+IBZyDkG0tBThaDdw1B2l asInUTeb9EiVfL/Zjdg5VWiF9LL7iS+9hTeVdR09vThQ/DhVbCNxVk+DtyBHsjOKifrVsYep WpRGBIAu3bK8eXtyvrw1igWTNs2wazJ71+0z2jMzbclKAyRHKU9JdN6Hkkgr2nPb561yjcB8 sIq1pFXKyO+nKy6SZYxOvHxCcjk2fkw6UmPU6/j/nQlj2lfOAgNVKuDLothIxzi8pndB8Jju KktE5HJqUUMXePkAYIxEQ0mMc8Po7tuXdejgPMwgP7x65xtfEqI0RuzbUioFltsp1jUaRwQZ MTsCeQDdjpgHsj+P2ZDeEKCbma4m6Ez/YWs4+zDm1X8uZDkZcfQlD9NldbKDJEXLIjYWo1PH hYepSffIWPyvBMBTW2W5FRjJ4vLRrJSUoEfJuPQ3vW9Y73foyo/qFoURHO48AinGPZ7PC7TF vUaNOTjKedrqHkaOcqB185ahG2had0xnFsDPlx5y In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/3/24 16:35, Tim Merrifield wrote: > VMCALL and VMMCALL instructions are used by x86 guests to request services > from the host VMM. Both VMCALL and VMMCALL are not restricted to CPL 0. > This allows userspace software like open-vm-tools to communicate directly > with the VMM. Could we please be frank and transparent about what you actually want here and how you expect this mechanism to be used? ... > This patchset introduces a new x86 process control flag to address this > concern. By setting the TIF_COCO_USER_HCALL thread information flag, the > process opts in to user-level hypercalls. The process, and anything it fork()s or execve()s, right? This inheritance model seems more suited to wrapping a tiny helper app around an existing binary, a la: prctl(ARCH_SET_COCO_USER_HCALL); execve("/existing/binary/that/i/surely/did/not/audit", ...); ... as opposed to something that you set in new versions of open-vm-tools after an extensive audit and a bug fixing campaign to clean up everything that the audit found.