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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 9FE5BC43382 for ; Thu, 27 Sep 2018 05:12:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6240E21566 for ; Thu, 27 Sep 2018 05:12:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6240E21566 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 S1727259AbeI0L2v (ORCPT ); Thu, 27 Sep 2018 07:28:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54304 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726469AbeI0L2u (ORCPT ); Thu, 27 Sep 2018 07:28:50 -0400 Received: from smtp.corp.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E6A5285A01; Thu, 27 Sep 2018 05:12:27 +0000 (UTC) Received: from localhost.localdomain (ovpn-12-101.pek2.redhat.com [10.72.12.101]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6E627A2791; Thu, 27 Sep 2018 05:12:19 +0000 (UTC) Subject: Re: [PATCH 1/4 v8] x86/ioremap: add a function ioremap_encrypted() to remap kdump old memory To: Baoquan He 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 References: <20180907081805.368-1-lijiang@redhat.com> <20180907081805.368-2-lijiang@redhat.com> <20180926022123.GA2555@MiWiFi-R3L-srv> <20180927020647.GH2555@MiWiFi-R3L-srv> From: lijiang Message-ID: Date: Thu, 27 Sep 2018 13:12:16 +0800 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: <20180927020647.GH2555@MiWiFi-R3L-srv> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Thu, 27 Sep 2018 05:12:28 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2018年09月27日 10:06, Baoquan He 写道: > 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. > Thank you, Baoquan. I will resend a series, and add Tom's Reviewed-by for all patches, also add Joerg's Acked-by for patch 3/4. Thanks. Lianbo