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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 F3C0DC433DF for ; Wed, 1 Jul 2020 18:20:30 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AF60B206A1 for ; Wed, 1 Jul 2020 18:20:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AF60B206A1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49xqK84SkhzDqbp for ; Thu, 2 Jul 2020 04:20:28 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 49xqGh70FNzDqDl for ; Thu, 2 Jul 2020 04:18:20 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) by bilbo.ozlabs.org (Postfix) with ESMTP id 49xqGh3Pl4z8tXv for ; Thu, 2 Jul 2020 04:18:20 +1000 (AEST) Received: by ozlabs.org (Postfix) id 49xqGh2mPyz9sTT; Thu, 2 Jul 2020 04:18:20 +1000 (AEST) Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; helo=mx0b-001b2d01.pphosted.com; envelope-from=hbathini@linux.ibm.com; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 49xqGg65Lsz9sPF for ; Thu, 2 Jul 2020 04:18:19 +1000 (AEST) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 061I3AKg069652; Wed, 1 Jul 2020 14:18:13 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 320s23dsbg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 01 Jul 2020 14:18:13 -0400 Received: from m0098417.ppops.net (m0098417.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 061IICwq116143; Wed, 1 Jul 2020 14:18:12 -0400 Received: from ppma02fra.de.ibm.com (47.49.7a9f.ip4.static.sl-reverse.com [159.122.73.71]) by mx0a-001b2d01.pphosted.com with ESMTP id 320s23dsay-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 01 Jul 2020 14:18:12 -0400 Received: from pps.filterd (ppma02fra.de.ibm.com [127.0.0.1]) by ppma02fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 061IGdL4011473; Wed, 1 Jul 2020 18:18:10 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma02fra.de.ibm.com with ESMTP id 31wwr7teqx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 01 Jul 2020 18:18:10 +0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 061IGlgD54133104 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 1 Jul 2020 18:16:47 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2C58B42061; Wed, 1 Jul 2020 18:18:07 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5625E42059; Wed, 1 Jul 2020 18:18:04 +0000 (GMT) Received: from [9.102.31.46] (unknown [9.102.31.46]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 1 Jul 2020 18:18:04 +0000 (GMT) Subject: Re: [PATCH 04/11] ppc64/kexec_file: avoid stomping memory used by special regions To: Dave Young References: <159319825403.16351.7253978047621755765.stgit@hbathini.in.ibm.com> <159319831192.16351.17443438699302756548.stgit@hbathini.in.ibm.com> <20200701074012.GA4496@dhcp-128-65.nay.redhat.com> From: Hari Bathini Message-ID: <6e96ae5a-91fd-726e-1eda-314f2317d8b4@linux.ibm.com> Date: Wed, 1 Jul 2020 23:48:03 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200701074012.GA4496@dhcp-128-65.nay.redhat.com> Content-Type: text/plain; charset=utf-8 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=2020-07-01_09:2020-07-01, 2020-07-01 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 clxscore=1015 impostorscore=0 phishscore=0 suspectscore=0 mlxlogscore=999 cotscore=-2147483648 mlxscore=0 spamscore=0 priorityscore=1501 bulkscore=0 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2007010126 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Pingfan Liu , Kexec-ml , Petr Tesarik , lkml , Sourabh Jain , Mahesh J Salgaonkar , linuxppc-dev , Vivek Goyal , Andrew Morton , Mimi Zohar , Thiago Jung Bauermann , Eric Biederman Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 01/07/20 1:10 pm, Dave Young wrote: > Hi Hari, > On 06/27/20 at 12:35am, Hari Bathini wrote: >> crashkernel region could have an overlap with special memory regions >> like opal, rtas, tce-table & such. These regions are referred to as >> exclude memory ranges. Setup this ranges during image probe in order >> to avoid them while finding the buffer for different kdump segments. >> Implement kexec_locate_mem_hole_ppc64() that locates a memory hole >> accounting for these ranges. Also, override arch_kexec_add_buffer() >> to locate a memory hole & later call __kexec_add_buffer() function >> with kbuf->mem set to skip the generic locate memory hole lookup. >> >> Signed-off-by: Hari Bathini >> --- >> arch/powerpc/include/asm/crashdump-ppc64.h | 10 + >> arch/powerpc/include/asm/kexec.h | 7 - >> arch/powerpc/kexec/elf_64.c | 7 + >> arch/powerpc/kexec/file_load_64.c | 292 ++++++++++++++++++++++++++++ >> 4 files changed, 312 insertions(+), 4 deletions(-) >> create mode 100644 arch/powerpc/include/asm/crashdump-ppc64.h >> > [snip] >> /** >> + * get_exclude_memory_ranges - Get exclude memory ranges. This list includes >> + * regions like opal/rtas, tce-table, initrd, >> + * kernel, htab which should be avoided while >> + * setting up kexec load segments. >> + * @mem_ranges: Range list to add the memory ranges to. >> + * >> + * Returns 0 on success, negative errno on error. >> + */ >> +static int get_exclude_memory_ranges(struct crash_mem **mem_ranges) >> +{ >> + int ret; >> + >> + ret = add_tce_mem_ranges(mem_ranges); >> + if (ret) >> + goto out; >> + >> + ret = add_initrd_mem_range(mem_ranges); >> + if (ret) >> + goto out; >> + >> + ret = add_htab_mem_range(mem_ranges); >> + if (ret) >> + goto out; >> + >> + ret = add_kernel_mem_range(mem_ranges); >> + if (ret) >> + goto out; >> + >> + ret = add_rtas_mem_range(mem_ranges, false); >> + if (ret) >> + goto out; >> + >> + ret = add_opal_mem_range(mem_ranges, false); >> + if (ret) >> + goto out; >> + >> + ret = add_reserved_ranges(mem_ranges); >> + if (ret) >> + goto out; >> + >> + /* exclude memory ranges should be sorted for easy lookup */ >> + sort_memory_ranges(*mem_ranges); >> +out: >> + if (ret) >> + pr_err("Failed to setup exclude memory ranges\n"); >> + return ret; >> +} > > I'm confused about the "overlap with crashkernel memory", does that mean > those normal kernel used memory could be put in crashkernel reserved There are regions that could overlap with crashkernel region but they are not normal kernel used memory though. These are regions that kernel and/or f/w chose to place at a particular address for real mode accessibility and/or memory layout between kernel & f/w kind of thing. > memory range? If so why can't just skip those areas while crashkernel > doing the reservation? crashkernel region has a dependency to be in the first memory block for it to be accessible in real mode. Accommodating this requirement while addressing other requirements would mean something like what we have now. A list of possible special memory regions in crashkernel region to take care of. I have plans to split crashkernel region into low & high to have exclusive regions for crashkernel, even if that means to have two of them. But that is for another day with its own set of complexities to deal with... Thanks Hari