From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (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 1E16C3EDACC for ; Wed, 20 May 2026 17:38:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779298723; cv=none; b=b8U8u83AwiwWUYQ5ySuzpx53aGlyMHvZ8N4yBfbR8JkOMXl4fkcXDf9eTfAj1+wWmdj4amxXYjxHYfDq6a5PT0wgkQbbdM07YQ9DWTOllc0iSl+27cGEFdkjrI9xmoHIQBTzfh2WBQ9hJGOLRQuwaoQA6/aO6Yd4CR2jdalIGhc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779298723; c=relaxed/simple; bh=vyFbmDoVPWkmerrHBrMGWkfgzBdsP+tG7jDlcj5Sg2k=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=umhJ9cTF0bg02J85Bb3y/cMP+z8yjP6T4Vnp44U1RjkhSRFhCf+/s94Y7d/PyZAQK9CvMk7FUZm4AgjXWaz3+j5Ub4IhMVY6iGmAJE6gO1tDu8ODYf1ZhWyE2JFRyJqaQUO13jU8Ox5tGVG+saiCOL6kVGom+EMyYUw5sYo7FI8= 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=mxisXGDK; arc=none smtp.client-ip=192.198.163.13 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="mxisXGDK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1779298722; x=1810834722; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=vyFbmDoVPWkmerrHBrMGWkfgzBdsP+tG7jDlcj5Sg2k=; b=mxisXGDK4xBEt1JXcF/+BbQXYSYef885KGsoTn3FBf7kzBTwbln9y4w/ Z9D5qGjWZZC34L53UH+NXB6qTLsmWfcjlI2L2F4V+wnDQUxZe5rn3YOqb pGRRA/Cgr9YpTDpi0vqFLnzOsukNmmYEqSAh5xlGL8oE8qnpIZz6BHxDQ 5qp7D4PxcsSbJzLPwGl4dJ3Sj9dhOanLksQ683xZ12AWdhE3yb74xZm+7 hvvJ9KZFClbRFwvzMc8VAkHG2Wi4zWGyS7KuKLUS9cuMrKtbSZ2oxqR/1 fcMN+YEqjcScFhVWNqK6eQRJZ99ORxMhzlaOjVDI1u9Ni3hk47Ty0UD+L Q==; X-CSE-ConnectionGUID: HXAiITVlS1m6RxxRl89wew== X-CSE-MsgGUID: AkbdBYU3Tu63ABMbtcdlUw== X-IronPort-AV: E=McAfee;i="6800,10657,11792"; a="82785840" X-IronPort-AV: E=Sophos;i="6.23,244,1770624000"; d="scan'208";a="82785840" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 May 2026 10:38:42 -0700 X-CSE-ConnectionGUID: BzcvtHkGQj2Xe11/ywkNSQ== X-CSE-MsgGUID: G5QdqfqrQ6akAcjjynBOow== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,244,1770624000"; d="scan'208";a="244250611" Received: from spandruv-mobl5.amr.corp.intel.com (HELO [10.125.109.190]) ([10.125.109.190]) by ORVIESA003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 May 2026 10:38:41 -0700 Message-ID: <509e8669-b052-437a-8896-69ac71dafde5@intel.com> Date: Wed, 20 May 2026 10:38:46 -0700 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v10 15/25] x86/virt/seamldr: Abort updates after a failed step To: Chao Gao , kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org Cc: binbin.wu@linux.intel.com, dave.hansen@linux.intel.com, djbw@kernel.org, ira.weiny@intel.com, kai.huang@intel.com, kas@kernel.org, nik.borisov@suse.com, paulmck@kernel.org, pbonzini@redhat.com, reinette.chatre@intel.com, rick.p.edgecombe@intel.com, sagis@google.com, seanjc@google.com, tony.lindgren@linux.intel.com, vannapurve@google.com, vishal.l.verma@intel.com, yilun.xu@linux.intel.com, xiaoyao.li@intel.com, yan.y.zhao@intel.com, Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" References: <20260520133909.409394-1-chao.gao@intel.com> <20260520133909.409394-16-chao.gao@intel.com> 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: <20260520133909.409394-16-chao.gao@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/20/26 06:38, Chao Gao wrote: > +static void ack_state(struct update_ctrl *ctrl, int result) > { > raw_spin_lock(&ctrl->lock); > > + ctrl->num_failed += !!result; > ctrl->num_ack++;...> @@ -239,8 +242,8 @@ static int do_seamldr_install_module(void *seamldr_params) > break; > } > > - ack_state(&update_ctrl); > - } while (curstate != MODULE_UPDATE_DONE); > + ack_state(&update_ctrl, ret); > + } while (curstate != MODULE_UPDATE_DONE && !READ_ONCE(update_ctrl.num_failed)); The READ_ONCE() is cute. But it's not really effective. It's also overly-complicated. update_ctrl.num_failed is just a single. Nothing cares if it is 1 or 2 or 999. So why have a count? Any reason this won't work? if (result) set_bit(0, ctrl->failed); ... and on the read side: test_bit(0, &update_ctrl.failed) That's 100% non-ambiguous. It doesn't have a counter where one isn't needed. It also can't even theoretically be messed up by the compiler.