Received: by 2002:ac0:a5a6:0:0:0:0:0 with SMTP id m35-v6csp2112971imm; Mon, 3 Sep 2018 19:43:42 -0700 (PDT) X-Google-Smtp-Source: ANB0VdaaNYKROEtkGm1r/+2JZGq3ioZ1XE/T2NevbJl+BihJSn/tl1036q6DovS77+0l7hKimOyU X-Received: by 2002:a62:da0b:: with SMTP id c11-v6mr32733284pfh.68.1536029022132; Mon, 03 Sep 2018 19:43:42 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1536029022; cv=none; d=google.com; s=arc-20160816; b=iq1ic6MAFWXAvNCXznJ9NysdHdUZmFtj1D994s085d8DegwAr0ym3EFf/Pmrfsv+yT 611zXZuV29R0a2Jini87KZMzEPf7NfmbpADvG1dwXqOY1wLwmZPsJ4Cr96pKTnnKEw8f J/ClWZ+SO6yvfPmcH7Kdt1U9D8J6qGXsUbfF5dkEqQ9UOfDcUIkCWzmweF5TY1f8mwYJ beDKLvAGcxBPIesg0awJZi6ImEAaq+rYWiMhX5cMhtBHh7UKVpHv6y6RHCwg8pEMbN0+ 9oucVnwBF9crZIiyQfgJaj2sSBc0pdjcMsDq2HXEf0DDePTsBZ1m9q0em6jbCqvIDYLR Yu/g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject:arc-authentication-results; bh=Q29vh2duVX+7KaCbF1RMsrSvfwMPv5KI62eWZEj/ouM=; b=1LvjqSGAzHxgIkBew7I62LqCjC+SFOJWjVt4xk4Kff8YeI2D54nUZmwBrRW9S394r/ RLK4XKtzQnI9S35L1pXAMpm58crp+NfcSAbevSZN//NCnTDjEMZwfspF8IVxh4g+anct m2mhATHfCUts3N9dTIAwy7WVHTBBsWLjZotG5UcctREqzNvDDtTe6pzc/UOLbfStImmR TTTGBe1jhM5lUbKOcZQ+YbPbnqWTTxHFul6b4VKqSzy95LSuuHzp014pg/pM+NpqI17o 4t03S6Uk2jren1ssYNd9+BQXYrOA2JvnY4OHCKCHQCocdGEfAuU4oGJYZaM/xR4QMTR1 7XyA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 31-v6si3500217pld.145.2018.09.03.19.43.27; Mon, 03 Sep 2018 19:43:42 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726335AbeIDHFU (ORCPT + 99 others); Tue, 4 Sep 2018 03:05:20 -0400 Received: from terminus.zytor.com ([198.137.202.136]:38665 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725990AbeIDHFU (ORCPT ); Tue, 4 Sep 2018 03:05:20 -0400 Received: from carbon-x1.hos.anvin.org (c-24-5-245-234.hsd1.ca.comcast.net [24.5.245.234] (may be forged)) (authenticated bits=0) by mail.zytor.com (8.15.2/8.15.2) with ESMTPSA id w842fYfL3526055 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO); Mon, 3 Sep 2018 19:41:35 -0700 Subject: Re: [PATCH 1/3] x86/boot: Add bit fields into xloadflags for 5-level kernel checking To: Baoquan He , tglx@linutronix.de, mingo@kernel.org, kirill.shutemov@linux.intel.com Cc: x86@kernel.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org References: <20180829141624.13985-1-bhe@redhat.com> <20180829141624.13985-2-bhe@redhat.com> From: "H. Peter Anvin" Message-ID: <6ea94875-ae07-6220-eb3e-d3f830cdac03@zytor.com> Date: Mon, 3 Sep 2018 19:41:29 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180829141624.13985-2-bhe@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I don't understand why there is any reason not to always enter the target kernel in 4-level mode. There certainly is no point whatsoever in having two xloadflags: the only thing that could possibly matter is whether or not the kernel in question *can* be entered in 5-level mode should that ever be necessary. -hpa