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 4A12EECDFBB for ; Fri, 20 Jul 2018 09:55:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 084CC2064D for ; Fri, 20 Jul 2018 09:55:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 084CC2064D 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 S1730139AbeGTKmp (ORCPT ); Fri, 20 Jul 2018 06:42:45 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:36870 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727167AbeGTKmo (ORCPT ); Fri, 20 Jul 2018 06:42:44 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8F5AE40776C2; Fri, 20 Jul 2018 09:55:15 +0000 (UTC) Received: from localhost.localdomain (ovpn-12-74.pek2.redhat.com [10.72.12.74]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 625FE1C640; Fri, 20 Jul 2018 09:55:07 +0000 (UTC) Subject: Re: [PATCH 1/5 V5] Add a function(ioremap_encrypted) for kdump when AMD sme enabled To: Borislav Petkov , Dave Young Cc: bhe@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, ebiederm@xmission.com, joro@8bytes.org, thomas.lendacky@amd.com, kexec@lists.infradead.org, iommu@lists.linux-foundation.org References: <4ae1cfb5-0a4b-2aac-2575-024e2c74826f@redhat.com> <895db996-febd-d50c-91af-4f1ef3d27bd8@redhat.com> <20180703111428.GB5748@zn.tnic> <4fbb843b-9597-a48b-8b6f-00e354b91950@redhat.com> <20180709092901.GA22182@nazgul.tnic> <20180713170857.GB17896@nazgul.tnic> <33453712-9b0b-e8b9-08a6-de09e0806dd6@redhat.com> <20180720052304.GA9146@dhcp-128-65.nay.redhat.com> <20180720073245.GA26926@nazgul.tnic> From: lijiang Message-ID: <562d8611-750d-3624-1a1b-df21f39812d6@redhat.com> Date: Fri, 20 Jul 2018 17:55:04 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <20180720073245.GA26926@nazgul.tnic> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 20 Jul 2018 09:55:15 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 20 Jul 2018 09:55:15 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'lijiang@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2018年07月20日 15:32, Borislav Petkov 写道: > On Fri, Jul 20, 2018 at 01:23:04PM +0800, Dave Young wrote: >>> Here, it doesn't need to dump MMIO space of the previous kernel, when the >>> kdump kernel boot, the MMIO address will be remapped in decryption manners, >>> but the MMIO address don't belong to the range of the crash reserved memory, >>> for the kdump kernel, the MMIO space(address) and IOMMU device table(address) >>> are outside address, whereas, the IOMMU device table is encrypted in the first >>> kernel, the kdump kernel will need to copy the content of IOMMU device table >>> from the first kernel when the kdump kernel boot, so the IOMMU device table will >>> be remapped in encryption manners. > > -ENOFCKINGPARSE > > I believe you're the only one who understands that humongous sentence.Sorry for this. > How about using a fullstop from time to time. And WTF is "encryption > manners"? > >>> So some of them require to be remapped in encryption manners, and some(address) >>> require to be remapped in decryption manners. > >> There could be some misunderstanding here. > > Hell yeah there's a misunderstanding! > > Can you folks first relax, sit down and explain the whole problem in > *plain* English using *simple* sentences. *Not* like the unparseable > mess above. Use simple, declaratory sentences and don't even try to > sound fancy: > > "The first kernel boots. It's memory is encrypted... Now, the second > kernel boots. It must do A because of B. In order to do A, it needs to > do C. Because D..." > > And so on. Explain what the problem is first. Then explain the proposed > solution. Explain *why* it needs to be done this way. > > When you've written your explanation, try to read it as someone who > doesn't know kdump and *think* hard whether your explanation makes > sense. If it doesn't, fix it and read it again. Rinse and repeat. Until > it is clear to unenlightened readers too. > Thanks for your advice, I will rewrite the log and send them again. > It is about time this hurried throwing of half-baked patches at > maintainers and seeing what sticks, stops! >