From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.15]) (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 4B135352092; Tue, 26 Aug 2025 14:22:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756218130; cv=none; b=Fln8xyRJ4qzjwHNanRDb4NocxRXpHSN6UJpn5nsiI57c/BjfmVpM847eXbJ27eTEF2TIMPjS7qS1X41VcOzrzT8ji4rImtZHW6afnFm1147rv8iyRikhEQuv7Id+aulkkTWdX66f3311MvWtVAUyRQWvGon9hCeQ6voZJOjJABo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756218130; c=relaxed/simple; bh=6be6FgDroGrcOGdtSfbCYCG2K25/DGBhTGRyV792SPA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=coMrm2K42jjYduZetyoFhTgV9mCKUdoyhPLddx8sC02eixApbuOiOCCmldRw0vjFfg86uPI4GvD0UjPGOORd4UPIg260yLzowxTsneVSqNTQOScYeccNUzXCdqyd75eTZASDWdll0/mxikN5pG8GpY0PpYJ/zMnLoaBCiJL0bc4= 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=CVY8AevA; arc=none smtp.client-ip=192.198.163.15 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="CVY8AevA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1756218129; x=1787754129; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=6be6FgDroGrcOGdtSfbCYCG2K25/DGBhTGRyV792SPA=; b=CVY8AevAd0oQX+tk789t7BEt7Q6fUZuG360IccTDf41Ai62Yxw6dnoEE OZFxahRsUXHMuw9Kb4uZAVyq77mVXRuTOqRU4h98uzOFZPQz+TRsnOWAA vM2QNF448QJrM1IaXPCvZqmadU1FuPi6KjrmlBR8rHL25gO9WFe5X7sRk cW1xfyf5XyP34uc+QuYeuCYf3YdQD9a3xD5O96EF4dcdte3cWfKBMhgAq U38Fn90uG4fmLzevx/m+JAw2lmfTVHSYJEQr9QXExj0JgXpKBKnKjHSno 2t5Uq455Bh7ntDEWANx/iU7/2QcaoXk3KtnlX7acwtahZDzTIhOKEco3E A==; X-CSE-ConnectionGUID: Byo8NECpQCqkyXXUbFjbuw== X-CSE-MsgGUID: hUEzRRdRQ7qNfSZhj0NmeQ== X-IronPort-AV: E=McAfee;i="6800,10657,11534"; a="58553302" X-IronPort-AV: E=Sophos;i="6.18,214,1751266800"; d="scan'208";a="58553302" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2025 07:22:08 -0700 X-CSE-ConnectionGUID: 7vZQSYnUTSmwsbbAIMJXxQ== X-CSE-MsgGUID: Adp2GUc5RcmriVSq9IMjmw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,214,1751266800"; d="scan'208";a="200531746" Received: from ldmartin-desk2.corp.intel.com (HELO [10.125.109.16]) ([10.125.109.16]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2025 07:22:07 -0700 Message-ID: Date: Tue, 26 Aug 2025 07:22:06 -0700 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 v3 1/1] iommu/sva: Invalidate KVA range on kernel TLB flush To: Baolu Lu , "Tian, Kevin" , Jason Gunthorpe Cc: Joerg Roedel , Will Deacon , Robin Murphy , Jann Horn , Vasant Hegde , Alistair Popple , Peter Zijlstra , Uladzislau Rezki , Jean-Philippe Brucker , Andy Lutomirski , "Lai, Yi1" , "iommu@lists.linux.dev" , "security@kernel.org" , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" , vishal.moola@gmail.com, Matthew Wilcox References: <20250806052505.3113108-1-baolu.lu@linux.intel.com> <20250806155223.GV184255@nvidia.com> <20250806160904.GX184255@nvidia.com> <62d21545-9e75-41e3-89a3-f21dda15bf16@intel.com> <4a8df0e8-bd5a-44e4-acce-46ba75594846@linux.intel.com> <20250807195154.GO184255@nvidia.com> <87bfc80e-258e-4193-a56c-3096608aec30@linux.intel.com> <9a649ff4-55fe-478a-bfd7-f3287534499a@intel.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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/25/25 19:49, Baolu Lu wrote: >> The three separate lists are needed because we're handling three >> distinct types of page deallocation. Grouping the pages this way allows >> the workqueue handler to free each type using the correct function. > > Please allow me to add more details. Right, I know why it got added this way: it was the quickest way to hack together a patch that fixes the IOMMU issue without refactoring anything. I agree that you have three cases: 1. A full on 'struct ptdesc' that needs its destructor run 2. An order-0 'struct page' 3. A higher-order 'struct page' Long-term, #2 and #3 probably need to get converted over to 'struct ptdesc'. They don't look _that_ hard to convert to me. Willy, Vishal, any other mm folks: do you agree? Short-term, I'd just consolidate your issue down to a single list. #1: For 'struct ptdesc', modify pte_free_kernel() to pass information in to pagetable_dtor_free() to tell it to use the deferred page table free list. Do this with a bit in the ptdesc or a new argument to pagetable_dtor_free(). #2. Just append these to the deferred page table free list. Easy. #3. The biggest hacky way to do this is to just treat the higher-order non-compound page and put the pages on the deferred page table free list one at a time. The other way to do it is to track down how this thing got allocated in the first place and make sure it's got __GFP_COMP metadata. If so, you can just use __free_pages() for everything. Yeah, it'll take a couple patches up front to refactor some things. But that refactoring will make things more consistent instead of adding adding complexity to deal with the inconsistency.