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=-2.3 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 E264EC43382 for ; Thu, 27 Sep 2018 02:06:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 86C0021508 for ; Thu, 27 Sep 2018 02:06:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 86C0021508 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727245AbeI0IWp (ORCPT ); Thu, 27 Sep 2018 04:22:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35411 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726682AbeI0IWp (ORCPT ); Thu, 27 Sep 2018 04:22:45 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 407ACC05B1EF; Thu, 27 Sep 2018 02:06:53 +0000 (UTC) Received: from localhost (ovpn-8-19.pek2.redhat.com [10.72.8.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A7F9F5DD92; Thu, 27 Sep 2018 02:06:50 +0000 (UTC) Date: Thu, 27 Sep 2018 10:06:47 +0800 From: Baoquan He To: lijiang Cc: linux-kernel@vger.kernel.org, joro@8bytes.org, mingo@redhat.com, ebiederm@xmission.com, hpa@zytor.com, tglx@linutronix.de, Dave Young , "Lendacky, Thomas" , kexec@lists.infradead.org Subject: Re: [PATCH 1/4 v8] x86/ioremap: add a function ioremap_encrypted() to remap kdump old memory Message-ID: <20180927020647.GH2555@MiWiFi-R3L-srv> References: <20180907081805.368-1-lijiang@redhat.com> <20180907081805.368-2-lijiang@redhat.com> <20180926022123.GA2555@MiWiFi-R3L-srv> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Thu, 27 Sep 2018 02:06:53 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Lianbo, On 09/26/18 at 05:34pm, lijiang wrote: > When SME is enabled on AMD machine, the memory is encrypted in the first > kernel. In this case, SME also needs to be enabled in kdump kernel, and > we have to remap the old memory with the memory encryption mask. > > Here we only talk about the case that SME is active in the first kernel, > and only care it's active too in kdump kernel. there are four cases we > need considered. > > a. dump vmcore > It is encrypted in the first kernel, and needs be read out in kdump > kernel. > > b. crash notes > When dumping vmcore, the people usually need to read the useful > information from notes, and the notes is also encrypted. > > c. iommu device table > It is allocated by kernel, need fill its pointer into mmio of amd iommu. > It's encrypted in the first kernel, need read the old content to analyze > and get useful information. > > d. mmio of amd iommu > Register reported by amd firmware, it's not RAM, we don't encrypt in > both the first kernel and kdump kernel. > > To achieve the goal, the solution is: > 1. add a new bool parameter "encrypted" to __ioremap_caller() > It is a low level function, and check the newly added parameter, if it's > true and in kdump kernel, will remap the memory with sme mask. > > 2. add a new function ioremap_encrypted() to explicitly passed in a "true" > value for "encrypted". > For above a, b, c, we will call ioremap_encrypted(); > > 3. adjust all existed ioremap wrapper functions, passed in "false" for > encrypted to make them an before. > > ioremap_encrypted()\ > ioremap_cache() | > ioremap_prot() | > ioremap_wt() |->__ioremap_caller() > ioremap_wc() | > ioremap_uc() | > ioremap_nocache() / Thanks, I think it's better. Since no code change, just patch log improvement, maybe you can repost a series and carry both Tom and Joerg's ACK.