From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 1E3A12D6409 for ; Mon, 5 Jan 2026 16:04:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767629065; cv=none; b=bvzW0MPilvtl0b91lJToA5/sqXE3ZSz7y5QAJ3k0QbL7y07bgLWe7xzseY820xXu4uTBk0p1mBbzxL9eVFXVLLRNzHVxgc9gmh7d+0Ywwr5VGeOMlknszSQrHWXc9+QF2EQnP7LVSN5nhV7nTbsr0NUufNlI6I/7P1K6BDuwDnw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767629065; c=relaxed/simple; bh=iY7eBrdjpKt6iDhe4qpuZUhWdA5JIJvxPNw5JJ556Cg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=A8dqZp9S5UuGf1n5dmFK8t9F5RJLqyF58tBq8kyZ4gfi9sRA5qGspEj9N4IUV1U0Tuol+KXvY/zBofkLKTx77Vm+DCy8hQn5kWF83O8nkDjzopUvrbxoomQSVjNs/4uJZvQds0cRgXZmqQfngIoIgXJwQRkIvYZlZGKxyunJss4= 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=kNmFpa8f; arc=none smtp.client-ip=198.175.65.10 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="kNmFpa8f" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1767629063; x=1799165063; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=iY7eBrdjpKt6iDhe4qpuZUhWdA5JIJvxPNw5JJ556Cg=; b=kNmFpa8f+Df1uJbTdysHaI3Vxl0biS6jfnNN2IulUt21JEWkv54xlpJE 346H9cy6CMvobim4K85egUbZr3YWB/Yq2ZXYW6Rgngyo1tuViAMpvzF/t 1SL0/fizQgB4FjoJTFcvuIOplQRsMxLf1D2Ir95FuGhTe4MvCkQ2HwJIt 3NF9DEd9mIMOibSZj9ONWxrfUMvh4Onnu7T/8xqyrJqeDY2bgKpxxRwIN fw6ppiFD9HLjrHS0ehpbsbicwTFLru+GEIOsOvU87Py4m5bAM5cKv8oYa TuA7Lt084qFQfje7oa/nlycnXDStkqvDD731pD6QhsxhRN37aak9mlFcE A==; X-CSE-ConnectionGUID: jKrLqbBfQPWKvXgeybA3yA== X-CSE-MsgGUID: BCo6AZukSLmMggmf2tIaHQ== X-IronPort-AV: E=McAfee;i="6800,10657,11662"; a="86413912" X-IronPort-AV: E=Sophos;i="6.21,203,1763452800"; d="scan'208";a="86413912" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2026 08:04:22 -0800 X-CSE-ConnectionGUID: cyBssC4yRSy/VRGn4IP/pA== X-CSE-MsgGUID: LsGiFLM8Sbiv6knOXIY5DQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,203,1763452800"; d="scan'208";a="239906954" Received: from sghuge-mobl2.amr.corp.intel.com (HELO [10.125.109.25]) ([10.125.109.25]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2026 08:04:22 -0800 Message-ID: Date: Mon, 5 Jan 2026 08:04:21 -0800 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 v2 0/3] Expose TDX Module version To: Kiryl Shutsemau , Chao Gao Cc: kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, x86@kernel.org, vishal.l.verma@intel.com, kai.huang@intel.com, dan.j.williams@intel.com, yilun.xu@linux.intel.com, vannapurve@google.com, Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Ingo Molnar , Rick Edgecombe , Thomas Gleixner References: <20260105074350.98564-1-chao.gao@intel.com> Content-Language: en-US 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/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 1/5/26 02:38, Kiryl Shutsemau wrote: >> To address this issue, this series exposes the TDX Module version as >> sysfs attributes of the tdx_host device [*] and also prints it in dmesg >> to keep a record. > The version information is also useful for the guest. Maybe we should > provide consistent interface for both sides? Could you elaborate a bit on what constitutes consistency here? Do you mean simply ensuring that the TDX module version _is_ exposed on both hosts and guests, like in: /sys/devices/faux/tdx_host/version and (making this one up): /sys/devices/faux/tdx_guest/version Note the "host" vs. "guest" ^^^^^ Or, that the TDX module version be exposed in the *same* ABI in both host and guest, like: /sys/devices/faux/tdx/version Generally, I find myself really wanting to know how this fits into the larger picture. Using this "faux" device really seems novel and TDX-specific. Should it be? What are other CPU vendors doing for this? SEV? CCA? S390? How are their firmware versions exposed? What about other things in the Intel world like CPU microcode or the billion other chunks of firmware? How about hypervisors? Do they expose their versions to guests with an explicit ABI? Are those exposed to userspace? For instance, I hear a lot of talk about updating the TDX module. But is this interface consistent with doing updates? Long term, I was hoping that TDX firmware could get treated like any other blob of modern firmware and have fwupd manage it, so I asked: https://chatgpt.com/share/695be06c-3d40-8012-97c9-2089fc33cbb3 My read on your approach here is that our new LLM overlords might consider it the "last resort".