From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933300AbdKGLkK (ORCPT ); Tue, 7 Nov 2017 06:40:10 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54022 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932716AbdKGLkE (ORCPT ); Tue, 7 Nov 2017 06:40:04 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 6309B1366 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=bhe@redhat.com Date: Tue, 7 Nov 2017 19:39:56 +0800 From: Baoquan He To: Jiri Bohac Cc: David Airlie , Dave Young , Vivek Goyal , Bjorn Helgaas , Toshi Kani , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , linux-kernel@vger.kernel.org, kexec@lists.infradead.org, Borislav Petkov Subject: Re: [PATCH] x86/kexec: Exclude GART aperture from vmcore Message-ID: <20171107113956.GC3669@x1> References: <20171103172822.4ty6yjhewroe4z4j@dwarf.suse.cz> <20171106024143.GA3669@x1> <20171106090155.p7jhe2m57whfxma3@dwarf.suse.cz> <20171106092729.GB3669@x1> <20171106095638.7iwlyjmlom3tqelt@dwarf.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171106095638.7iwlyjmlom3tqelt@dwarf.suse.cz> User-Agent: Mutt/1.7.0 (2016-08-17) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 07 Nov 2017 11:40:04 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/06/17 at 10:56am, Jiri Bohac wrote: > On Mon, Nov 06, 2017 at 05:27:29PM +0800, Baoquan He wrote: > > > 00100000-c7e7ffff : System RAM > > > 0b000000-0b792eb5 : Kernel code > > > 0b792eb6-0bd5d47f : Kernel data > > > 0c274000-0c3c8fff : Kernel bss > > > b7000000-c6ffffff : Crash kernel > > > > It's weird, gart aperture located in crashkernel region? > > Ooops! I sent you a /proc/iomem from a different boot than the > dmesg, whith different crashkernel= commandline. Sorry, this is > the correct /proc/iomem: > > > 00000000-00000fff : Reserved > 00001000-0009d7ff : System RAM > 0009d800-0009ffff : Reserved > 000a0000-000bffff : PCI Bus 0000:00 > 000c0000-000cafff : PCI Bus 0000:00 > 000c0000-000cafff : Video ROM > 000cb000-000ccfff : Adapter ROM > 000ce000-000fffff : Reserved > 000f0000-000fffff : System ROM > 00100000-c7e7ffff : System RAM AGP: Mapping aperture over RAM [mem 0xb8000000-0xbbffffff] (65536KB) So on this system, gart is located inside 00100000-c7e7ffff : System RAM. I saw you defined the variable as xx_stolen_xx, does it mean that the memory region where aperture located will be stolen from memory domain? I am wondering if it will cause error when access this region from direct mapping since allocate_aperture() is called in pci_iommu_alloc(), while in setup_arch() we have built the direct mapping for all system ram. Did I miss anything? Anyway, if it should be excluded from crash memory region, can we dig it away from /proc/iomem so that it's a hole in /proc/vmcore? Like this, we don't worry about the user space kexec utility either. Could be I still don't get it, may need to read the code of gart. Thanks Baoquan > c3000000-c77fffff : Crash kernel > c7e80000-c7e8afff : ACPI Tables > c7e8b000-c7e8cfff : ACPI Non-volatile Storage > c7e8d000-c7ffffff : Reserved > c8000000-ce0fffff : PCI Bus 0000:00 > c8000000-c80003ff : IOAPIC 1 > c8014000-c80143ff : 0000:00:11.0 > c8014000-c80143ff : ahci > c8014400-c80144ff : 0000:00:12.2 > c8014400-c80144ff : ehci_hcd > c8014800-c80148ff : 0000:00:13.2 > c8014800-c80148ff : ehci_hcd > c8015000-c8015fff : 0000:00:12.0 > c8015000-c8015fff : ohci_hcd > c8016000-c8016fff : 0000:00:12.1 > c8016000-c8016fff : ohci_hcd > c8017000-c8017fff : 0000:00:13.0 > c8017000-c8017fff : ohci_hcd > c8018000-c8018fff : 0000:00:13.1 > c8018000-c8018fff : ohci_hcd > c8019000-c8019fff : 0000:00:14.5 > c8019000-c8019fff : ohci_hcd > ca000000-cdffffff : PCI Bus 0000:01 > ca000000-cbffffff : 0000:01:00.0 > ca000000-cbffffff : bnx2 > cc000000-cdffffff : 0000:01:00.1 > cc000000-cdffffff : bnx2 > ce000000-ce0fffff : PCI Bus 0000:02 > ce000000-ce00ffff : 0000:02:06.0 > d0000000-d7ffffff : PCI Bus 0000:00 > d0000000-d7ffffff : PCI Bus 0000:02 > d0000000-d7ffffff : 0000:02:06.0 > e0000000-efffffff : Reserved > e0000000-efffffff : pnp 00:00 > e0000000-e02fffff : PCI MMCONFIG 0000 [bus 00-02] > fec00000-fec0ffff : Reserved > fec00000-fec003ff : IOAPIC 0 > fec10000-fec1001f : pnp 00:05 > fed00000-fed003ff : HPET 2 > fed00000-fed003ff : PNP0103:00 > fed40000-fed45000 : PCI Bus 0000:00 > fee00000-fee00fff : Local APIC > fee00000-fee00fff : Reserved > fee00000-fee00fff : pnp 00:00 > fff00000-ffffffff : Reserved > fff00000-ffffffff : pnp 00:05 > 100000000-837ffffff : System RAM > 4df000000-4df792eb5 : Kernel code > 4df792eb6-4dfd5d47f : Kernel data > 4e0274000-4e03c8fff : Kernel bss > 831000000-8374fffff : Crash kernel > > Sorry for the confusion! > > -- > Jiri Bohac > SUSE Labs, Prague, Czechia >