Received: by 2002:a05:6a10:206:0:0:0:0 with SMTP id 6csp1918716pxj; Wed, 19 May 2021 17:44:02 -0700 (PDT) X-Google-Smtp-Source: ABdhPJw8MpcI11tfY3oyf345K/AcMlMscY++2SI1XzmG7idM/cZwdudXXSvGzxZ08TdhgbBfcpYP X-Received: by 2002:a17:906:b0d:: with SMTP id u13mr1811350ejg.159.1621471442390; Wed, 19 May 2021 17:44:02 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1621471442; cv=none; d=google.com; s=arc-20160816; b=McXQi0wtEAXT7MUVhixI6Yn/tQ5kUdPkVt9edpP42ouJ5+v6cKP3k/Wr/K6z1/CuLT KmoGsi8ZPoiTGah1VdmG+Xgih59LJ/Lra6+zs4/LFUJzHn5SxyQcTpGGEqshjLcvc2JL kUvEGYB81+MOhHGozum67FdjuO94nKXbz+JMqB1mpc5p7l2+HScA3tYpjTKVHNBaf73v o1jC66ZCfP1Q1CY9TLIPHWK1ZOcOQQXPWefkXYJwEKSXsENQINfVrS8V6kqJK5wfcozH WPgvZdP28gaMCWN9mUA5xRwuVyJ+FL4r8YHLbjpSCzOnM8JHxez2H1RfSAh5QFuZHiP+ qjRw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:content-language :in-reply-to:mime-version:user-agent:date:message-id:from:references :cc:to:subject:ironport-sdr:ironport-sdr; bh=kAEMK0L4HhWtBhvhCFUedKiGyDvEyQ9eKIUnLVk0cDM=; b=eN6C+/5R+vDONM3l0rrfHbjHuvrX+n6Wdzp5qQQ/HOJ0ns3zJudhRSt/foMhBkUgSj DcXqGys8KhEJKWNSqYDmz1aTRi2N/OQVYkXXvjrDoPT3u3RleOCAVzIZKi29g0JGPTmx GbgKMZMEp6yzMF1LzQre4UUrqUryfDUKSmQmqv6PcohPcYiv6+1tpgB1c6s+LHzyptpR ad7T0OJ2hPpN/tNoZj57AYm08xCm258uPaIjeCJ1sE1XsPBCGkXwxRvsZkFKUOL6r+KV Qwi0D91u7cstKhjTY1jv4CYbJl0RpMBugvPUYuF180DE4UAof1Teko9y817fKFy8Inav YO8Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id j25si805272edr.84.2021.05.19.17.43.37; Wed, 19 May 2021 17:44:02 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229953AbhETAoI (ORCPT + 99 others); Wed, 19 May 2021 20:44:08 -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