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=-6.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 85A47C433E0 for ; Thu, 30 Jul 2020 06:05:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 695632084D for ; Thu, 30 Jul 2020 06:05:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728644AbgG3GFc (ORCPT ); Thu, 30 Jul 2020 02:05:32 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:33950 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725892AbgG3GFb (ORCPT ); Thu, 30 Jul 2020 02:05:31 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06U5Wafr139489; Thu, 30 Jul 2020 02:05:18 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 32k9qv9guh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 30 Jul 2020 02:05:18 -0400 Received: from m0098410.ppops.net (m0098410.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 06U5j1N9025907; Thu, 30 Jul 2020 02:05:18 -0400 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 32k9qv9gt7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 30 Jul 2020 02:05:17 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06U65Fdq005152; Thu, 30 Jul 2020 06:05:15 GMT Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by ppma04ams.nl.ibm.com with ESMTP id 32gcy4nupm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 30 Jul 2020 06:05:15 +0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06U65CPF31064358 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 30 Jul 2020 06:05:12 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 05A31A406F; Thu, 30 Jul 2020 06:05:12 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 499B2A4065; Thu, 30 Jul 2020 06:05:08 +0000 (GMT) Received: from [9.102.24.129] (unknown [9.102.24.129]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 30 Jul 2020 06:05:08 +0000 (GMT) Subject: Re: [RESEND PATCH v5 00/11] ppc64: enable kdump support for kexec_file_load syscall To: piliu , Michael Ellerman , Andrew Morton Cc: kernel test robot , Laurent Dufour , Dave Young , Thiago Jung Bauermann , Mahesh J Salgaonkar , Sourabh Jain , Vivek Goyal , Petr Tesarik , linuxppc-dev , Kexec-ml , lkml , Eric Biederman , Mimi Zohar , Nayna Jain References: <159579157320.5790.6748078824637688685.stgit@hbathini> <23911b9d-7534-031c-6f98-80f90439c834@redhat.com> From: Hari Bathini Message-ID: Date: Thu, 30 Jul 2020 11:35:07 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <23911b9d-7534-031c-6f98-80f90439c834@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-07-30_03:2020-07-29,2020-07-30 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 phishscore=0 clxscore=1015 bulkscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 malwarescore=0 priorityscore=1501 lowpriorityscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007300042 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28/07/20 8:02 am, piliu wrote: > > > On 07/27/2020 03:36 AM, Hari Bathini wrote: >> Sorry! There was a gateway issue on my system while posting v5, due to >> which some patches did not make it through. Resending... >> >> This patch series enables kdump support for kexec_file_load system >> call (kexec -s -p) on PPC64. The changes are inspired from kexec-tools >> code but heavily modified for kernel consumption. >> >> The first patch adds a weak arch_kexec_locate_mem_hole() function to >> override locate memory hole logic suiting arch needs. There are some >> special regions in ppc64 which should be avoided while loading buffer >> & there are multiple callers to kexec_add_buffer making it complicated >> to maintain range sanity and using generic lookup at the same time. >> >> The second patch marks ppc64 specific code within arch/powerpc/kexec >> and arch/powerpc/purgatory to make the subsequent code changes easy >> to understand. >> >> The next patch adds helper function to setup different memory ranges >> needed for loading kdump kernel, booting into it and exporting the >> crashing kernel's elfcore. >> >> The fourth patch overrides arch_kexec_locate_mem_hole() function to >> locate memory hole for kdump segments by accounting for the special >> memory regions, referred to as excluded memory ranges, and sets >> kbuf->mem when a suitable memory region is found. >> >> The fifth patch moves walk_drmem_lmbs() out of .init section with >> a few changes to reuse it for setting up kdump kernel's usable memory >> ranges. The next patch uses walk_drmem_lmbs() to look up the LMBs >> and set linux,drconf-usable-memory & linux,usable-memory properties >> in order to restrict kdump kernel's memory usage. >> >> The seventh patch updates purgatory to setup r8 & r9 with opal base >> and opal entry addresses respectively to aid kernels built with >> CONFIG_PPC_EARLY_DEBUG_OPAL enabled. The next patch setups up backup >> region as a kexec segment while loading kdump kernel and teaches >> purgatory to copy data from source to destination. >> >> Patch 09 builds the elfcore header for the running kernel & passes >> the info to kdump kernel via "elfcorehdr=" parameter to export as >> /proc/vmcore file. The next patch sets up the memory reserve map >> for the kexec kernel and also claims kdump support for kdump as >> all the necessary changes are added. >> >> The last patch fixes a lookup issue for `kexec -l -s` case when >> memory is reserved for crashkernel. >> >> Tested the changes successfully on P8, P9 lpars, couple of OpenPOWER >> boxes, one with secureboot enabled, KVM guest and a simulator. >> >> v4 -> v5: >> * Dropped patches 07/12 & 08/12 and updated purgatory to do everything >> in assembly. Hello Pingfan, Sorry, I missed out on responding to this. > I guess you achieve this by carefully selecting instruction to avoid > relocation issue, right? Yes. No far branching or reference to data from elsewhere. Thanks Hari