From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) (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 61BE8C8F0; Sun, 1 Mar 2026 00:33:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.21 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772325198; cv=none; b=LDsz60SP86mr0kbvHDlOMbZTY1FXCy2qsRQeFDmJvb2cVzu3v/yG8t5nzqaQUWEPLjPjc0NpNbqU+3oq9EV8mX5NUTiHDRTyMCJ8N34dA54TRZCD0vTzYWB5CMdfFETCeX+l96w/YeoOh0xsaETFZfhfKkdrxF+1/WmaNVl7goQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772325198; c=relaxed/simple; bh=RjVMdUwVgUTKPDzRUPPSggtxyOQ+VjLTRUYEoujXp4k=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=NH0E16AtARTRscY6vtJYSzWBZUb3Zxj4x7QZUZjldxQGNK/M/78VRgXr4b489BVgUyAPKKUkjU7yjsqk6DHIBNLhx5XCjWxCGpHcWd4junnUIZJVY+a/6PKjShd8A/Th0PLQGWViOZDSBIzEhFE46X6cKBKPDfLD0pHoMJeJmu4= 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=F2NLtyHU; arc=none smtp.client-ip=198.175.65.21 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="F2NLtyHU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1772325196; x=1803861196; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=RjVMdUwVgUTKPDzRUPPSggtxyOQ+VjLTRUYEoujXp4k=; b=F2NLtyHUoYEj2PER7z0P0KNxDCiXdRv+IAlVlPwYLEGPZucr5nEbnlbo 1E9FZmzSK9p5jN60RIsx7hOxDRPQQMXCFhuMF4vSxuMnGcdfbQ8tWzyYS prI5lC8oUFR+dNKrOFfumrMvvRCWBUgogspLJVsEoglTaniuTDMdKi8/G FY3ufSRSh0+IgudoBQ/eywkyaMOhjvOurdHNjTvMC2txN7jo0Rot9TZU2 t51VjjRxBqi1w25OEqrTNg1NGuG+AiLePAj8/FdJqeF+YtubHc3Kt0XA2 flb7QbuIY5pexeONa3lDrldlMt7IY3YO5LLGZnCGHbMdda9lkKZd59/Zp A==; X-CSE-ConnectionGUID: 6/LgceagSA6UHF2RjEbudg== X-CSE-MsgGUID: m99FjHosS5+xKJLm+SFPQg== X-IronPort-AV: E=McAfee;i="6800,10657,11715"; a="73245741" X-IronPort-AV: E=Sophos;i="6.21,317,1763452800"; d="scan'208";a="73245741" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Feb 2026 16:33:16 -0800 X-CSE-ConnectionGUID: /KJcsrUTTP6nfrSiSUAQBg== X-CSE-MsgGUID: B9brrkSmR2OPjMKiA6+ysQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,317,1763452800"; d="scan'208";a="222238064" Received: from sghuge-mobl2.amr.corp.intel.com (HELO [10.125.108.27]) ([10.125.108.27]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Feb 2026 16:33:16 -0800 Message-ID: <72356849-27d0-46c7-b659-c1a3b260de8c@intel.com> Date: Sat, 28 Feb 2026 16:33:18 -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] x86/cpu/centaur: Disable X86_FEATURE_FSGSBASE on Zhaoxin C4600 To: Yao Zi , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Andrew Cooper , "H. Peter Anvin" Cc: x86@kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20260228173704.62460-1-me@ziyao.cc> 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: <20260228173704.62460-1-me@ziyao.cc> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/28/26 09:37, Yao Zi wrote: > Let's disable the feature on this problematic CPU and warn the user > about the quirk. x86_model_id is used to match the platform to avoid > unexpectedly breaking other CentaurHauls cores with conflicting > family/model ID. Wait a sec. There are lots of different microarchitectures with the same family/model and no other way to identify them but the model id string? We've used string in a handful of places, but it's an absolute last resort. Are you *sure* there's no stepping or anything? I kinda think we should keep this like all the other vendors and keep it to model/family/stepping. If the vendor has grouped too many non-vulnerable CPUs under that, then ... this is going to be a good learning to bring back to the CPU design team. If you're changing the CPU in a way that it's possible to regress things, you *need* to bump the model or stepping. Period. If you don't, the baby might get thrown out with the bathwater. Please resend this with a normal x86_match_cpu() and x86_cpu_id[] array.