From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) (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 E758E1C3BF0 for ; Tue, 14 Jan 2025 16:41:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736872910; cv=none; b=UaJxd2w4gGybm77/U5SM69IH9d1dnrxX6deGxQxyVvC2fmxrFAaxC+QTzj0tSQN6SLaX8rptnRqY3zh0RNiqDv1AT5qMLG7SjlaryypdFRaufkDajVmbMVmfy6RwB4wcQiVTzgLHmlfIm6oN14y9eJcK21om83hmLZ9Did7orxI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736872910; c=relaxed/simple; bh=EfInt1WsjltaOU3Tdef5m9ZTLvgXmxAH6LIZx1mqUSo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jyNYDk+Q6oZsfmvjZp/aNvdopd1WTmLDsibfgrm/5/HxDXNFBspUiGK8PTsn2hfviiQx5IfS8TZlRya+64XzRAj9Cf547U3DAIPJa/RQFNC7oZnj+BqE68yf3Xn+4oa8nN1VNU395bJJ0kEoIKNTGgqfa4CLQlIeqwbRa1yvK34= 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=F3E4GQXp; arc=none smtp.client-ip=198.175.65.15 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="F3E4GQXp" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1736872909; x=1768408909; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=EfInt1WsjltaOU3Tdef5m9ZTLvgXmxAH6LIZx1mqUSo=; b=F3E4GQXpUWbYJzr8W2JDwmKJCEIWGBRredNNj8jvkjSPFIwOC4w/0f5n 2lWqlWh2rk6sekO/U/gD8l1+EygB0my8vyMFPcC0Z0A9ybQU4TrxYgksm RmGvvVF/6jaHcA078mEbgYbOKaSSw350LWiWQKVtoaJVfhgpeijsPIghU znecMNppsZJ919vvgROF+T16yiRc3f80WVe2FEsyE5MjSIZeiV+mQNpzn tI4DHbb/VDOztb68OAbaxl+q3mgsIrEtae2ZMmgNenKmX9agUO3oS7RqK m1j2oBpwOJMIS0hGWKcqcixmCHP3wP0kzdgi0SEX6FNSU/JY426pIbPyU w==; X-CSE-ConnectionGUID: rU+PF0B5R/++FQKCZylGXg== X-CSE-MsgGUID: Uy3KqbVBTIi533dfnSpoUw== X-IronPort-AV: E=McAfee;i="6700,10204,11315"; a="40857532" X-IronPort-AV: E=Sophos;i="6.12,314,1728975600"; d="scan'208";a="40857532" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jan 2025 08:41:49 -0800 X-CSE-ConnectionGUID: pyLrUZ68QN6e8ETTFQrzlw== X-CSE-MsgGUID: ffjdQEQzT6KRv3wxHsBjiA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,199,1725346800"; d="scan'208";a="109841501" Received: from ssimmeri-mobl2.amr.corp.intel.com (HELO [10.124.223.199]) ([10.124.223.199]) by ORVIESA003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jan 2025 08:41:47 -0800 Message-ID: <3350ece7-9eab-404c-8cad-f0a307781068@intel.com> Date: Tue, 14 Jan 2025 08:41:48 -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 v4 05/12] x86/mm: add INVLPGB support code To: Tom Lendacky , Rik van Riel , x86@kernel.org Cc: linux-kernel@vger.kernel.org, bp@alien8.de, peterz@infradead.org, dave.hansen@linux.intel.com, zhengqi.arch@bytedance.com, nadav.amit@gmail.com, kernel-team@meta.com, linux-mm@kvack.org, akpm@linux-foundation.org, jannh@google.com References: <20250112155453.1104139-1-riel@surriel.com> <20250112155453.1104139-6-riel@surriel.com> <685632f2-44a4-a7fd-063b-1d426896f297@amd.com> <7045d1666ac5722820a43fffa7f2e6fb3c2eb485.camel@surriel.com> <5085e0aa-5921-40c2-c018-c947b98f5152@amd.com> <6737e3d6-65fa-46b3-9413-e26f4ba8efdd@intel.com> <0e20a86c-bc4f-2774-3cf7-4424af7becad@amd.com> <0e3f94d0-0d2f-b815-009d-e2e3da375727@amd.com> 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: <0e3f94d0-0d2f-b815-009d-e2e3da375727@amd.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 1/14/25 08:30, Tom Lendacky wrote: >> Let me remove it again, now that we seem to have a >> consensus that a panic is preferable to a wrong >> TLB flush. > I believe the instruction will #GP if any of the ECX[30:16] reserved > bits are non-zero (although the APM doesn't document that), in addition > to ECX[15:0] being greater than allowed. But what if 0x80000000 is > passed in. That would set ECX[31] with a zero count field, which is > valid for the instruction, but the input is obviously bogus. > > I think the safest thing to do is make the extra_count parameter an > unsigned int and check if it is greater than invlpgb_count_max. Not sure > what to actually do at that point, though... panic()? WARN() with full > TLB flush? How about we give 'extra_count' a type that can't bleed over into the stride bits: static inline void __invlpgb(unsigned long asid, unsigned long pcid, unsigned long addr, u16 extra_count, bool pmd_stride, u8 flags) plus a check on CPUID 8000_0008h EDX[15:0] to make sure it's not 0xffff.