From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (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 15A75407CCC for ; Mon, 15 Jun 2026 16:05:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781539534; cv=none; b=C0KQyu780A1wlWy0rUpVrKda1Ws61UdpBA9UGg4IXMQWSoC2jMmtHeSvdi5KHZXRTIeemgjgmIPQHloiQscIGWvXWnX8XCult6x+1IX/iYOWwSgsacmG0pP+pKNZTH92YAnCmDGIzPF0wlbWgx4Ly/eK+aYswKo9jTBAWsmHig8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781539534; c=relaxed/simple; bh=8Xglb0VN4Knikj/QNg75wE2/nmnV9n4uzhX1MLj9t7E=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=lRTONPLNsUMTBJFTP5aEEYmjspGgpgYqFQAnVnadQcvX/eVqZIyiktUsIm28NEWLGvqEqsPzFsbC3P8ZmkUmzJLacugOxdplJHvevEPPnShRqX+27lvTnDN0GsHBU9XZnymHzRPsJAK4gQT/kHh6J5QNoET8TdnIBc1qGG01BOU= 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=Wd83GgNF; arc=none smtp.client-ip=192.198.163.11 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="Wd83GgNF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1781539533; x=1813075533; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=8Xglb0VN4Knikj/QNg75wE2/nmnV9n4uzhX1MLj9t7E=; b=Wd83GgNFF3aDgSqpt3cL9yyQ3iBt3LRT+c9WivEk4unhSafF+oMqTyBH CiId5aIiKphNPiJioJHRiGYdK6LezaGG5A501khv9bolBUpDR6+impZ2z BnB9FurnxFHPKc0yCBGqb07MsLyRaq/6+KW1b4uNx0tP7dbho9TU0/JX5 5SS+qPSZByWe4eAwtq4/bH8WU3aSlHS1JGxTA7S8selbQkIKiyJyO3KMb vxOomf1SNUCR2016sae1J7r6v56yXEgihiT8zuJz+GG89kMRwJo6sTSwU BvyQ99dlgqypChUJ4DbCZmtSRVGTUcnhIVeB65whV18CcCTGGueXBojmL Q==; X-CSE-ConnectionGUID: r0fVWoaYQJmTpB6X2vHIgQ== X-CSE-MsgGUID: /w40hK9eQtW+CLGZSXH8HA== X-IronPort-AV: E=McAfee;i="6800,10657,11818"; a="92844133" X-IronPort-AV: E=Sophos;i="6.24,206,1774335600"; d="scan'208";a="92844133" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jun 2026 09:05:32 -0700 X-CSE-ConnectionGUID: 9LCrFjFoQ9Si0kPc9ahtjw== X-CSE-MsgGUID: 0/taGEr3TBO1rbn6FXFYkg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,206,1774335600"; d="scan'208";a="285627829" Received: from bradocaj-mobl.ger.corp.intel.com (HELO [10.125.111.24]) ([10.125.111.24]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jun 2026 09:05:31 -0700 Message-ID: Date: Mon, 15 Jun 2026 09:05:33 -0700 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 01/15] x86/virt/tdx: Read global metadata for TDX Module Extensions To: "Dan Williams (nvidia)" , Xu Yilun , kas@kernel.org, rick.p.edgecombe@intel.com, x86@kernel.org, peter.fang@intel.com Cc: linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, sohil.mehta@intel.com, yilun.xu@intel.com, baolu.lu@linux.intel.com, zhenzhong.duan@intel.com, xiaoyao.li@intel.com References: <20260522034128.3144354-1-yilun.xu@linux.intel.com> <20260522034128.3144354-2-yilun.xu@linux.intel.com> <6a2c863a681d6_9b85510064@djbw-dev.notmuch> 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: <6a2c863a681d6_9b85510064@djbw-dev.notmuch> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/12/26 15:20, Dan Williams (nvidia) wrote: >> Check TDX_FEATURES0 before reading these metadata. If a feature is >> advertised, a failure in reading associated metadata causes the entire >> TDX initialization to fail, otherwise skip. > Others already commented on the patch ordering, so I will just comment > on the changelog to recommend referring back to the "any available > extension, all the time" implementation policy rather than saying "Linux > requires" which is ambiguous. One other note on this: the current Linux policy of "any available extension, all the time" is the simplest possible functional policy. If Linux has one policy, I think that's the one it should have. That said, I'm open to the idea that users might desire other policies. We should absolutely explore them another day in another series.