From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 62A71C25B78 for ; Tue, 4 Jun 2024 16:28:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=LIxwrU3nVB+P6vBfeh79kkn3l1i9mwzBZgnXeNgy9BE=; b=Yop9OZ6LCP0wZg 1PzwbDkXy1nSCYWcaPk2zBsUzYJ5TFJn7tRdF+5wmbw2Foz9FF7wanZoPqA89XKVGPKq0eRJ4avd7 XFPcX1idbfPzr1CTso4Myp/r+ZFWK4vXffQp8GN/h3iaITV7/RwBuuByUFyNC8p3o0FJweKl/UvoW Ds4QuNTBMkwaPBG4M5yYo508rzzHIGGf36ZKFUXii8KVP7sBimE99PZSAqXeOxFCaKlErVXMMxYCR 8bA4c4n5TTkaYZVrXFwDGPTaRXCyd9Eaeue5MX0vdP+UXlD37OdY78lhwXKrZdL/7ZqkQnYtHQ2CW IB9CrPI8hFZ87TtWfXDA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sEX13-000000037Pp-3ckz; Tue, 04 Jun 2024 16:28:05 +0000 Received: from mgamail.intel.com ([192.198.163.8]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sEX10-000000037P2-1ulz for kexec@lists.infradead.org; Tue, 04 Jun 2024 16:28:04 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1717518483; x=1749054483; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=/lnf6CYK7u74rxaN3J//73iP7uRLzgmeeUan2mDXC58=; b=NuRpy5Q6GMQ5nM0/AfRw2PDsQtzPZcC2l/agxlE9SFiC8hNM6gYn8CII XnJQSje9TjtG7aTvCkOO+laCQPXGqXGycHavZW3Ty2ETD5q5Jc7wQiqWb MmZdxjeMDw4cpwflvjlAvoPRNJHJRJxSnUwGC2IG8CFXFQUj/cSbiAMd/ PKw6CIxlAHJLiua3yb19C7Df+jVjIEzUEHkHFO4stBuzymNno9yAX9o8D 7JNBlGjJFzmPTXmyS1drB41M0E+jDwn2JjfCuB+X3pJ8ve2lfSDvvNyEp NYyHhMSKuJg7IX7e+JECfVHdPu8jlTsJ5Qa3lbFNLB9CYuVWXs2344XPj w==; X-CSE-ConnectionGUID: IIG3jJaTS9ayRDlZ2gFnEQ== X-CSE-MsgGUID: JTQFMN6HTg+ZiTonpRl/+w== X-IronPort-AV: E=McAfee;i="6600,9927,11093"; a="31615680" X-IronPort-AV: E=Sophos;i="6.08,214,1712646000"; d="scan'208";a="31615680" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Jun 2024 09:28:02 -0700 X-CSE-ConnectionGUID: 2bpf4B91TpKpUNHk9CEgqw== X-CSE-MsgGUID: Ur5EqPltQjyX9vlxq9vRCg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,214,1712646000"; d="scan'208";a="37230836" Received: from cdpresto-mobl2.amr.corp.intel.com.amr.corp.intel.com (HELO [10.125.108.218]) ([10.125.108.218]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Jun 2024 09:28:00 -0700 Message-ID: <68943e0b-8d82-42de-8f09-058e97d9a392@intel.com> Date: Tue, 4 Jun 2024 09:27:59 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCHv11 11/19] x86/tdx: Convert shared memory back to private on kexec To: "Kirill A. Shutemov" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "Rafael J. Wysocki" , Peter Zijlstra , Adrian Hunter , Kuppuswamy Sathyanarayanan , Elena Reshetova , Jun Nakajima , Rick Edgecombe , Tom Lendacky , "Kalra, Ashish" , Sean Christopherson , "Huang, Kai" , Ard Biesheuvel , Baoquan He , "H. Peter Anvin" , "K. Y. Srinivasan" , Haiyang Zhang , kexec@lists.infradead.org, linux-hyperv@vger.kernel.org, linux-acpi@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, Tao Liu References: <20240528095522.509667-1-kirill.shutemov@linux.intel.com> <20240528095522.509667-12-kirill.shutemov@linux.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: <20240528095522.509667-12-kirill.shutemov@linux.intel.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240604_092802_634109_E58BE1EF X-CRM114-Status: GOOD ( 10.00 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On 5/28/24 02:55, Kirill A. Shutemov wrote: > +/* Stop new private<->shared conversions */ > +static void tdx_kexec_begin(bool crash) > +{ > + /* > + * Crash kernel reaches here with interrupts disabled: can't wait for > + * conversions to finish. > + * > + * If race happened, just report and proceed. > + */ > + if (!set_memory_enc_stop_conversion(!crash)) > + pr_warn("Failed to stop shared<->private conversions\n"); > +} I don't like having to pass 'crash' in here. If interrupts are the problem we have ways of testing for those directly. If it's being in an oops that's a problem, we have 'oops_in_progress' for that. In other words, I'd much rather this function (or better yet set_memory_enc_stop_conversion() itself) use some existing API to change its behavior in a crash rather than have the context be passed down and twiddled through several levels of function calls. There are a ton of these in the console code: if (oops_in_progress) foo_trylock(); else foo_lock(); To me, that's a billion times more clear than a 'wait' argument that gets derives from who-knows-what that I have to trace through ten levels of function calls. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec