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 X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6AA27C433ED for ; Thu, 20 May 2021 00:42:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 393E06112F for ; Thu, 20 May 2021 00:42:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230109AbhETAoJ (ORCPT ); Wed, 19 May 2021 20:44:09 -0400 Received: from mga11.intel.com ([192.55.52.93]:23486 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229498AbhETAoI (ORCPT ); Wed, 19 May 2021 20:44:08 -0400 IronPort-SDR: G38rjGFrGFMmIzzq9zSCNC2FIEZ1lw/drxLgd6EpiBa3jQzXLFvPUTldfqmz/ybLwpYqjAWJvF O/yBrfwJ7Q4w== X-IronPort-AV: E=McAfee;i="6200,9189,9989"; a="198020388" X-IronPort-AV: E=Sophos;i="5.82,313,1613462400"; d="scan'208";a="198020388" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 May 2021 17:42:48 -0700 IronPort-SDR: TzleCD93hzaPE30Lz10g4uMxhaIwdyf3PTd+7AgAJv1TskKUfgnh170Od6xUu2Y47a9tPldA0l fa7nnbaIzsOw== X-IronPort-AV: E=Sophos;i="5.82,313,1613462400"; d="scan'208";a="411964025" Received: from ccheung-mobl.amr.corp.intel.com (HELO skuppusw-mobl5.amr.corp.intel.com) ([10.212.97.108]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 May 2021 17:42:47 -0700 Subject: Re: [RFC v2-fix 1/1] x86/boot: Add a trampoline for APs booting in 64-bit mode To: Dan Williams Cc: Peter Zijlstra , Andy Lutomirski , Dave Hansen , Tony Luck , Andi Kleen , Kirill Shutemov , Kuppuswamy Sathyanarayanan , Raj Ashok , Sean Christopherson , Linux Kernel Mailing List , Sean Christopherson , Kai Huang References: <20210518005404.258660-1-sathyanarayanan.kuppuswamy@linux.intel.com> <861a316c-09f6-5969-6238-e402fca917db@linux.intel.com> From: "Kuppuswamy, Sathyanarayanan" Message-ID: <2977129b-c568-8ce5-9a85-31473096719f@linux.intel.com> Date: Wed, 19 May 2021 17:42:44 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/19/21 5:40 PM, Dan Williams wrote: > I would clarify how the boot code uses this: > > "When a bootloader hands off to the kernel in 32-bit mode an IDT with > a 2-byte limit and 4-byte base is needed. When a boot loader hands off > to a kernel 64-bit mode the base address extends to 8-bytes. Reserve > enough space for either scenario." I will add it. Thanks. -- Sathyanarayanan Kuppuswamy Linux Kernel Developer