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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 38D9CC43218 for ; Fri, 26 Apr 2019 10:16:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF1A72077B for ; Fri, 26 Apr 2019 10:16:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726155AbfDZKQl (ORCPT ); Fri, 26 Apr 2019 06:16:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58948 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725935AbfDZKQl (ORCPT ); Fri, 26 Apr 2019 06:16:41 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4C4D23082B4D; Fri, 26 Apr 2019 10:16:41 +0000 (UTC) Received: from localhost (ovpn-12-17.pek2.redhat.com [10.72.12.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9360E600C7; Fri, 26 Apr 2019 10:16:38 +0000 (UTC) Date: Fri, 26 Apr 2019 18:16:35 +0800 From: Baoquan He To: Borislav Petkov Cc: "H. Peter Anvin" , Junichi Nomura , dyoung@redhat.com, Kairui Song , Thomas Gleixner , linux-kernel@vger.kernel.org, Chao Fan , "x86@kernel.org" , "kexec@lists.infradead.org" Subject: Re: [RFC PATCH] kexec, x86/boot: map systab region in identity mapping before accessing it Message-ID: <20190426101635.GQ3584@localhost.localdomain> References: <20190419101733.GA10324@zn.tnic> <20190419105014.GE11060@MiWiFi-R3L-srv> <20190419112801.GB10324@zn.tnic> <20190419113621.GD10324@zn.tnic> <20190422143346.GD3584@localhost.localdomain> <20190422151723.GD21457@zn.tnic> <20190426095134.GP3584@localhost.localdomain> <20190426095800.GB4608@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190426095800.GB4608@zn.tnic> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Fri, 26 Apr 2019 10:16:41 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/26/19 at 11:58am, Borislav Petkov wrote: > On Fri, Apr 26, 2019 at 05:51:34PM +0800, Baoquan He wrote: > > I can make a patch to add a bit into xloadflags, to indicate that this > > is kexec-ed kernel. It can help to differentiate kexec-ed kernel from > > kdump kernel. > > From the recent snafu, the only thing we needed is to differentiate > between the *first* kernel and the following kernel(s) which has been > started/loaded using a kexec syscall. OK. To make sure I got it, the loader type 0xD is enough for this, right? It's fine to me, we can add it later if needed. I remember there's an issue in intel/amd iommu, in which we need differentiate between kexec/kdump kernel, but not very sure. I will check it when I have time to work on that. Thanks Baoquan