From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17F1AC4332F for ; Thu, 9 Nov 2023 16:50:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343565AbjKIQub (ORCPT ); Thu, 9 Nov 2023 11:50:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229916AbjKIQu3 (ORCPT ); Thu, 9 Nov 2023 11:50:29 -0500 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B8EF171A; Thu, 9 Nov 2023 08:50:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1699548627; x=1731084627; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=VyVhtf+NykkTPIVinfE56gh7ZbmN9guPJS5K2mzlesM=; b=NOLhb0vKxBSUyTb5Hyk+UZHkGnHuD5UAr8/H8DZ+LXQpU0jrte3lx9rF Z0MLAR2uz0jCJezF0hDtkCuqIF/GLfXOueMrH08TKLzp9sdLsHihKc9Cx GqmUL9sCU8+/kKpwn7sxIvpZN0d2QNzwmDXEVM0ak6O80P9S+VvnPTndk T/1zmKM00NmA6h/76Ul1lEFbLofYqFEV4AsYiGtH2g4kpB4/qOIAESnMA 2pof9ZgonEsw0W0dB+MFJgZ5OP0zR6MekNyFZ4FVFuVhV6+NJXiT87oFX NgIDZf4c0wrrtYsZYjK8CI0zOqMGOWbAQKCEWpc8IMwSFCIBvu6hwzCvT g==; X-IronPort-AV: E=McAfee;i="6600,9927,10889"; a="8679260" X-IronPort-AV: E=Sophos;i="6.03,289,1694761200"; d="scan'208";a="8679260" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Nov 2023 08:50:27 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10889"; a="756930772" X-IronPort-AV: E=Sophos;i="6.03,289,1694761200"; d="scan'208";a="756930772" Received: from tiwariv-mobl.amr.corp.intel.com (HELO [10.212.165.194]) ([10.212.165.194]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Nov 2023 08:50:25 -0800 Message-ID: Date: Thu, 9 Nov 2023 08:50:25 -0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] x86/mm: Check cc_vendor when printing memory encryption info Content-Language: en-US To: Jeremi Piotrowski , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , linux-kernel@vger.kernel.org, Michael Kelley , Dexuan Cui Cc: linux-hyperv@vger.kernel.org, stefan.bader@canonical.com, tim.gardner@canonical.com, roxana.nicolescu@canonical.com, cascardo@canonical.com, kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, kirill.shutemov@linux.intel.com, sashal@kernel.org References: <1699546489-4606-1-git-send-email-jpiotrowski@linux.microsoft.com> <16ea75a9-8c94-4665-ae04-32d08aa4ebb2@intel.com> <58abbc79-64d4-41f9-9fd2-1de7826fbbf6@linux.microsoft.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/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: <58abbc79-64d4-41f9-9fd2-1de7826fbbf6@linux.microsoft.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/9/23 08:35, Jeremi Piotrowski wrote: > On 09/11/2023 17:25, Dave Hansen wrote: >> On 11/9/23 08:14, Jeremi Piotrowski wrote: >> ... >>> pr_info("Memory Encryption Features active:"); >>> >>> - if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) { >>> + if (cc_vendor == CC_VENDOR_INTEL) { >>> pr_cont(" Intel TDX\n"); >>> return; >>> } >> >> Why aren't these guests setting X86_FEATURE_TDX_GUEST? > > They could if we can confirm that the code gated behind > cpu_feature_enabled(X86_FEATURE_TDX_GUEST) is correct when running with TD partitioning. Let me elaborate a bit on my question. X86_FEATURE_TDX_GUEST is set based on some specific gunk that shows up in CPUID in TDX guests. I *believe* it's in one of the CPUID leaves that the VMM has no control over. So, first, what in practice is keeping tdx_early_init() from running on these "TD partitioning" systems? Because it's either not running, or I'm misreading the code horribly. > It still makes sense to have these prints based on the cc_xxx abstractions. I'm not sure I'm following. For instance, let's say that someone came up with a nutty reason to do MKTME in Linux. We'd need a host-side contraption that sets CC_ATTR_MEM_ENCRYPT and so forth. It would also, obviously, set cc_vendor=CC_VENDOR_INTEL just like host-side SME sets cc_vendor=CC_VENDOR_AMD. Then we'd have to go back and disentangle all the places where we assumed CC_VENDOR_INTEL==TDX. That, combined with this patch's apparent disregard for why X86_FEATURE_TDX_GUEST isn't getting set makes me think that the big picture was not considered here and this patch represents the quickest hack to get the right spew out to dmesg that is desired.