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 8BC2B24290C; Tue, 29 Apr 2025 16:12:06 +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=1745943128; cv=none; b=FWkKn/Tx0n9HnB4KRWlORG3LV9EUrdq6XSrirp9W9oRMXuiEpQSuvoURSjnhZupivt/K0/wvnYmCGX5RFK2qN5xyme2HKgUCoGBxXZgLvpUQbbb36A/PCSh6FTBNTTdyVySESvmDWK9XR/A1nZzWxC0ei/1ZiZmrG5sxsvLOaj4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745943128; c=relaxed/simple; bh=/RPzRSwGYU/TqtNWAxnjSN65OBBFBuTwX8sdhARd81w=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=k6bJrDJuaYTG+rMAVcT9uie9BSjz3QE7EwuzniKow1XpdFKsM1ZZuwEhPwb2jNxyeDy5B/LTFX7NYY4Olc4uo3nim8JGciiaUGWkb3brFid7j8fQa3yO7aX3c7BFrB3hDGWAbbzR684GW7sBhvxYQntLAPpTvg668vqAB70Pkgg= 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=Mvk6iBAL; 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="Mvk6iBAL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1745943127; x=1777479127; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=/RPzRSwGYU/TqtNWAxnjSN65OBBFBuTwX8sdhARd81w=; b=Mvk6iBALOLCZMosSJXieogMcnz9NHLIl+14RWfaCSZOIgGuJ+WCPKP7C 0wpEUVRn0GchdbJsWYGXz9hdPR32X+WM9K4yBu43Dw+gtMrHkt/Zby2k9 ohyLluqm2hZeXp9Yeoa/4fJTfwKSN3f//TUataX0eNNd4FefDHndunXjo 3GqIwhgrB7M1S8buFxCQ6CfK+/vivQrLIjcKH7z35bsX00ngqlaYJUh1E sJhrptC46uH5sIFWCs5C7TIzmAcD4/wRl3RnR7DYmFQ/tpYW5rnKbedal TwuJRQwx4QXCxObwXTq6bCFp/mQQi2vFlyAN5DOwxXEylE2MUCiY6qdzb w==; X-CSE-ConnectionGUID: GM4nj81wQUSqlpCQh7Zx5A== X-CSE-MsgGUID: jIUOFBzgRu+PP0xpTB/5GQ== X-IronPort-AV: E=McAfee;i="6700,10204,11418"; a="51243422" X-IronPort-AV: E=Sophos;i="6.15,249,1739865600"; d="scan'208";a="51243422" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Apr 2025 09:12:06 -0700 X-CSE-ConnectionGUID: b38aJ8qqSqC5eqNimrxdFQ== X-CSE-MsgGUID: 1d8Et1s7SmqzvGll9TJyYw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,249,1739865600"; d="scan'208";a="134856497" Received: from sramkris-mobl1.amr.corp.intel.com (HELO [10.124.223.107]) ([10.124.223.107]) by orviesa008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Apr 2025 09:12:00 -0700 Message-ID: Date: Tue, 29 Apr 2025 09:11:57 -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 v5 00/25] context_tracking,x86: Defer some IPIs until a user->kernel transition To: Valentin Schneider , linux-kernel@vger.kernel.org, virtualization@lists.linux.dev, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, linux-perf-users@vger.kernel.org, kvm@vger.kernel.org, linux-arch@vger.kernel.org, linux-modules@vger.kernel.org, linux-trace-kernel@vger.kernel.org, rcu@vger.kernel.org, linux-hardening@vger.kernel.org, linux-kselftest@vger.kernel.org, bpf@vger.kernel.org Cc: Juri Lelli , Marcelo Tosatti , Yair Podemsky , Josh Poimboeuf , Daniel Wagner , Petr Tesarik , Nicolas Saenz Julienne , Frederic Weisbecker , "Paul E. McKenney" , Dave Hansen , Sean Christopherson , Juergen Gross , Ajay Kaher , Alexey Makhalov , Broadcom internal kernel review list , Russell King , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , Pawan Gupta , Paolo Bonzini , Arnd Bergmann , Jason Baron , Steven Rostedt , Ard Biesheuvel , Luis Chamberlain , Petr Pavlu , Sami Tolvanen , Daniel Gomez , Naveen N Rao , Anil S Keshavamurthy , "David S. Miller" , Masami Hiramatsu , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman , Kees Cook , Shuah Khan , Masahiro Yamada , Alice Ryhl , Miguel Ojeda , "Mike Rapoport (Microsoft)" , Rong Xu , Rafael Aquini , Song Liu , Andrii Nakryiko , Dan Carpenter , Brian Gerst , "Kirill A. Shutemov" , Benjamin Berg , Vishal Annapurve , Randy Dunlap , John Stultz , Tiezhu Yang References: <20250429113242.998312-1-vschneid@redhat.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: <20250429113242.998312-1-vschneid@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit I don't think we should do this series. If folks want this functionality, they should get a new CPU that can flush the TLB without IPIs.