From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from host81-137-131-225.in-addr.btopenworld.com ([81.137.131.225] helo=zimbra.overnetdata.com) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1X5BLA-00083i-4c for kexec@lists.infradead.org; Thu, 10 Jul 2014 10:12:37 +0000 Message-ID: <53BE66C5.6090604@overnetdata.com> Date: Thu, 10 Jul 2014 11:11:17 +0100 From: Anthony Wright MIME-Version: 1.0 Subject: Re: Can't load bzImage crashkernel on xen system with 32 bit kernel References: <53BBC94B.8060905@overnetdata.com> <20140710074713.GA23099@dhcp-17-89.nay.redhat.com> In-Reply-To: <20140710074713.GA23099@dhcp-17-89.nay.redhat.com> Content-Type: multipart/mixed; boundary="------------020202040908070200000808" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: WANG Chao Cc: kexec@lists.infradead.org This is a multi-part message in MIME format. --------------020202040908070200000808 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hi Chao, Thanks for looking at this. On 10/07/2014 08:47, WANG Chao wrote: > Hi, Anthony > > On 07/08/14 at 11:34am, Anthony Wright wrote: >> After successfully modifying kexec-tools to get it to load a crashkernel >> on a standard 32 bit linux 3.10.17 kernel, I tried to get it to load the >> same crashkernel on the same 32 bit linux kernel running under xen >> 4.4.0, but get the error "Cannot load ". >> >> I've patched the code to include some diagnostics, and the problem is >> caused by add_memmap() reporting that it's been called with overlapping >> memory. >> >> It's called twice, the first time it's called with: >> address: 0x00000000 >> size: 0x0009f800 >> type: 0 >> >> This comes from info->backup_src_* >> >> The second time it is passed >> address: 0x00000000 >> size: 0x00000000 >> type: 0 >> >> This is derived from the crash_reserved_mem[] array, which has one >> element with the values: >> start: 0x0000000000000000 (16 0's) >> end: 0xffffffffffffffff (16 f's) > Why it looks like that? crashkernel memory region shouldn't be that > extreme. Is it something to do with xen 4.4.0? The xen hypervisor is 64 bit, but the Dom0 linux kernel is 32 bit. I realise this is a bit of a strange combination, but we run this way for historical reasons. > Maybe there's something wrong when it retrieves crashkernel reserved > region. How you does your /proc/iomem look like? > > Turn on debug option (-d) would be helpful too. I've attached a copy of /proc/iomem and the output of kexec with the -d flag. >> The problem isn't caused by the zero size because the maths in >> add_memmap, uses size to calculate end which overflows back again, and >> (partially) cancels out the error. The problem is caused by the two >> memory blocks being based at 0x0, causing the blocks to overlap. > The overflow issue should be easy to fix once we figure out why the > crash_reserved_mem[] has a element like that. > > Thanks > WANG Chao thanks, Anthony. --------------020202040908070200000808 Content-Type: text/plain; charset=windows-1252; name="iomem" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="iomem" 00000000-00000fff : reserved 00001000-0009efff : System RAM 0009f000-0009f7ff : RAM buffer 0009f800-000fffff : reserved 000a0000-000bffff : PCI Bus 0000:00 000c0000-000cebff : Video ROM 000d0000-000dffff : PCI Bus 0000:00 000f0000-000fffff : System ROM 00100000-cff9ffff : System RAM 01000000-015897cd : Kernel code 015897ce-0182debf : Kernel data 018e6000-019bbfff : Kernel bss 18000000-1fffffff : Crash kernel cffa0000-cffaffff : ACPI Tables cffb0000-cffdffff : ACPI Non-volatile Storage cffe0000-cfffffff : reserved d0000000-dfffffff : PCI Bus 0000:00 d0000000-dfffffff : PCI Bus 0000:01 d0000000-dfffffff : 0000:01:05.0 e0000000-efffffff : PCI MMCONFIG 0000 [bus 00-ff] e0000000-efffffff : pnp 00:0c f0000000-febfffff : PCI Bus 0000:00 fdf00000-fdffffff : PCI Bus 0000:03 fdff8000-fdffbfff : 0000:03:00.0 fdff8000-fdffbfff : r8169 fdfff000-fdffffff : 0000:03:00.0 fdfff000-fdffffff : r8169 fe7f4000-fe7f7fff : 0000:00:14.2 fe7fa000-fe7fafff : 0000:00:14.5 fe7fa000-fe7fafff : ohci_hcd fe7fb000-fe7fbfff : 0000:00:13.1 fe7fb000-fe7fbfff : ohci_hcd fe7fc000-fe7fcfff : 0000:00:13.0 fe7fc000-fe7fcfff : ohci_hcd fe7fd000-fe7fdfff : 0000:00:12.1 fe7fd000-fe7fdfff : ohci_hcd fe7fe000-fe7fefff : 0000:00:12.0 fe7fe000-fe7fefff : ohci_hcd fe7ff400-fe7ff4ff : 0000:00:13.2 fe7ff400-fe7ff4ff : ehci_hcd fe7ff800-fe7ff8ff : 0000:00:12.2 fe7ff800-fe7ff8ff : ehci_hcd fe7ffc00-fe7fffff : 0000:00:11.0 fe7ffc00-fe7fffff : ahci fe800000-fe9fffff : PCI Bus 0000:01 fe800000-fe8fffff : 0000:01:05.0 fe9f0000-fe9fffff : 0000:01:05.0 fea00000-feafffff : PCI Bus 0000:02 feaff800-feafffff : 0000:02:00.0 feaff800-feafffff : firewire_ohci feb00000-febfffff : PCI Bus 0000:03 febe0000-febfffff : 0000:03:00.0 fec00000-fec003ff : IOAPIC 0 fec10000-fec1001f : pnp 00:08 fee00000-feefffff : reserved fee00000-fee00fff : Local APIC fee00000-fee00fff : pnp 00:07 ffb80000-ffbfffff : pnp 00:08 fff00000-ffffffff : reserved 100000000-21fffffff : System RAM fd00000000-ffffffffff : reserved --------------020202040908070200000808 Content-Type: text/x-log; name="kexec-debug.log" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="kexec-debug.log" kernel: 0xb6dbb008 kernel_size: 0x3b09f0 MEMORY RANGES 0000000000000100-000000000009f7ff (0) 000000000009f800-000000000009ffff (1) 00000000000e7000-00000000000fffff (1) 0000000000100000-00000000cff9ffff (0) 00000000cffa0000-00000000cffaffff (2) 00000000cffb0000-00000000cffdffff (3) 00000000cffe0000-00000000cfffffff (1) 00000000fee00000-00000000feefffff (1) 00000000fff00000-00000000ffffffff (1) 0000000100000000-000000021fffffff (0) 000000fd00000000-000000ffffffffff (1) bzImage is relocatable get_backup_area: 0000000000000000-000000000009f7ff : System RAM CRASH MEMORY RANGES 0000000000000000-000000000009f7ff (0) 000000000009f800-ffffffffffffffff (1) 00000000000e7000-ffffffffffffffff (1) 0000000000100000-ffffffffffffffff (0) 0000000038000000-ffffffffffffffff (0) 00000000cffa0000-ffffffffffffffff (2) 00000000cffb0000-ffffffffffffffff (3) 00000000cffe0000-ffffffffffffffff (1) 00000000fee00000-ffffffffffffffff (1) 00000000fff00000-ffffffffffffffff (1) 0000000100000000-ffffffffffffffff (0) 000000fd00000000-ffffffffffffffff (1) 0000000000000000-000000ffffffffff (0) Memmap after adding segment 0000000000000000-000000000009f7ff (0) Cannot load /boot/master/XenMaster-6.9.0/kernel --------------020202040908070200000808 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec --------------020202040908070200000808--