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 94BF934575A for ; Wed, 11 Feb 2026 18:40:22 +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=1770835223; cv=none; b=nR0Hn9IQ8RtXQxV7uvoWd471RBXli3En/zOyTcMZM1h3l/C/77nMrvX8zgZM+ZP5VfP509aaCwIg7DCkm0kPKnDk/FeMvgy4L8NJ+4XLwHykH9IAxQGzyx14ioUxQz7SJnDqhc6QYcermIxqztVp3KKTbvP4gkrz7FDXanrbng0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770835223; c=relaxed/simple; bh=PqEcofzPtPVvbjGcrGrQhO7/g5Iq0a4LO4O8aFl5YTE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tDgciupehyc9WlOUQqIiG2GQhIrNXTo5bgiKOG2pe6p9C6TFcGDDVtjachtdJ2Ywo7++qrjyJJeHeL0pAxXRgSnK5XavynOgHIkNH4QPyRcpMsvrjAaFP0StKQA9xX0k+lyLZoeeGdhjjG5fbGjOkgLt5AYHZkdzEGHYM6zFgn4= 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=WkHHZR8o; 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="WkHHZR8o" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1770835222; x=1802371222; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=PqEcofzPtPVvbjGcrGrQhO7/g5Iq0a4LO4O8aFl5YTE=; b=WkHHZR8oldY3vuDwS0jE97XMfgCqNwNOiIziuVRPc0LhkZIdR78yNUem B3AzK2XKB/K2zuOm023TjAmwcQ+K3pv0QlYWgRzLjQuo7VB9q378ALjqG ggGuM79aCevCHUK2DPu85wQthW1gmEVWF/4pDULhhaOhx7X7Dg85TtySN qEzXmCjK3AilSKVrCZM0J4hbkNxLuSZQSTV74dz02n2YXzHb4p2mgIzYY JzcqFL85eOZO3NJR5DLs+Urhaa5YxUWRzMcAPt590YGxdH5bcUKxQ1xNb grtxkoSNz2tQwGqTnhaa21WVKZW4wFtjSQSFdDdDviJCtEuyKEUrLzj12 Q==; X-CSE-ConnectionGUID: k/+9FrW5Rh2LEhLaeiAvPw== X-CSE-MsgGUID: FlS0cGuFSMiIAPw70BsVzw== X-IronPort-AV: E=McAfee;i="6800,10657,11698"; a="82630683" X-IronPort-AV: E=Sophos;i="6.21,285,1763452800"; d="scan'208";a="82630683" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Feb 2026 10:40:22 -0800 X-CSE-ConnectionGUID: oLw9SjP4SMqgMv5H7vqmoA== X-CSE-MsgGUID: HHI+uBJYRuq/08c+bw0jpg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,285,1763452800"; d="scan'208";a="211334157" Received: from sghuge-mobl2.amr.corp.intel.com (HELO [10.125.108.146]) ([10.125.108.146]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Feb 2026 10:40:22 -0800 Message-ID: Date: Wed, 11 Feb 2026 10:40:21 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 4/6] x86/cpu: Add platform ID to CPU info structure To: Borislav Petkov , Dave Hansen Cc: linux-kernel@vger.kernel.org, sohil.mehta@intel.com, zhao1.liu@intel.com, "H. Peter Anvin" , Ingo Molnar , Jon Kohler , Pawan Gupta , "Peter Zijlstra (Intel)" , Thomas Gleixner , Tony Luck , x86@kernel.org References: <20260206231438.720FF4E3@davehans-spike.ostc.intel.com> <20260206231445.2D569730@davehans-spike.ostc.intel.com> <20260208213735.GCaYkCHz1cxp-Ivm7L@fat_crate.local> 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: <20260208213735.GCaYkCHz1cxp-Ivm7L@fat_crate.local> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/8/26 13:37, Borislav Petkov wrote: > On Fri, Feb 06, 2026 at 03:14:45PM -0800, Dave Hansen wrote: >> diff -puN arch/x86/include/asm/processor.h~cpu-x86_stepping arch/x86/include/asm/processor.h >> --- a/arch/x86/include/asm/processor.h~cpu-x86_stepping 2026-02-06 15:14:23.528790212 -0800 >> +++ b/arch/x86/include/asm/processor.h 2026-02-06 15:14:23.567791582 -0800 >> @@ -140,6 +140,8 @@ struct cpuinfo_x86 { >> __u32 x86_vfm; >> }; >> __u8 x86_stepping; >> + /* Intel-only. 3 bits: */ >> + __u8 x86_platform_id; > Can we call this something more generic so that we can do: > > /* On Intel: platform ID > /* On AMD: something else > > so that we can use this on both vendors? > > I don't have any usage in mind on AMD now but it might come in handy some day. I'm racking my brain but having a hard time coming up with a good name that would work for unknown future AMD things. ;) Any suggestions? I'm not married to the name in any way. I could prefix it with 'intel_' to make it more clear that someone _can_ do a union in the future, like we do with "Hardware defined CPU-type". Or we could do: union { u8 intel_platform_id; u8 amd_unused; }; to make it utterly clear that it's free for use on AMD if someone goes looking for AMD-usable space.