Re: [Xen-devel] [PATCH v2] xen, kdump: handle pv domain in paddr_vmcoreinfo_note()

[Petr Tesarik]

On Tue, 11 Apr 2017 15:00:58 +0200
Daniel Kiper <daniel.kiper@xxxxxxxxxx> wrote:

> On Tue, Apr 11, 2017 at 02:45:43PM +0200, Juergen Gross wrote:
> > On 03/04/17 14:42, Daniel Kiper wrote:
> > > On Fri, Mar 31, 2017 at 12:14:38PM +0200, Juergen Gross wrote:
> > >> For kdump to work correctly it needs the physical address of
> > >> vmcoreinfo_note. When running as dom0 this means the virtual address
> > >> has to be translated to the related machine address.
> > >>
> > >> paddr_vmcoreinfo_note() is meant to do the translation via
> > >> __pa_symbol() only, but being attributed "weak" it can be replaced
> > >> easily in Xen case.
> > >>
> > >> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> > >
> > > Have you tested this patch with latest crash tool? Do dom0 and Xen
> > > hypervisor analysis work without any issue (at least basic commands
> > > like dmesg, bt, ps, etc.)? If yes for both you can add:
> > >
> > > Reviewed-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
> >
> > So can I add your R-b: now?
> 
> My R-b is still valid. Though, let's wait for Petr's Tested-by. He
> did makedumpfile tests but I asked him to do crash tool tests too.
> I think it is important.

Tested-by: Petr Tesarik <ptesarik@xxxxxxxx>

I copied the complete /proc/vmcore to a directory on disk. Exactly
as expected, crash works both without the patch and with the patch, as
it does not use VMCOREINFO at all (instead, crash obtains the
information from kernel debuginfo directly).

Without the patch:

morricone:/abuild/dumps/2017-04-11-16:38/:[0]# crash vmlinux vmcore 

crash 7.1.8
Copyright (C) 2002-2016  Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010  IBM Corporation
Copyright (C) 1999-2006  Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012  Fujitsu Limited
Copyright (C) 2006, 2007  VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011  NEC Corporation
Copyright (C) 1999, 2002, 2007  Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002  Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions.  Enter "help copying" to see the conditions.
This program has absolutely no warranty.  Enter "help warranty" for details.
 
crash: vmlinux: no .gnu_debuglink section
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu"...

      KERNEL: vmlinux                           
    DUMPFILE: vmcore
        CPUS: 12 [OFFLINE: 11]
        DATE: Tue Apr 11 16:37:34 2017
      UPTIME: 00:11:51
LOAD AVERAGE: 0.04, 0.08, 0.08
       TASKS: 269
    NODENAME: morricone
     RELEASE: 4.11.0-rc5-default-pt+
     VERSION: #1 SMP PREEMPT Thu Apr 6 17:40:53 CEST 2017
     MACHINE: x86_64  (2400 Mhz)
      MEMORY: 16 GB
       PANIC: "sysrq: SysRq : Trigger a crash"
         PID: 12009
     COMMAND: "bash"
        TASK: ffff8804065d2080  [THREAD_INFO: ffff8804065d2080]
         CPU: 7
       STATE: TASK_RUNNING (SYSRQ)

crash> 


With the patch included:

morricone:/abuild/dumps/2017-04-11-12:52/:[0]# crash vmlinux vmcore  

crash 7.1.8
Copyright (C) 2002-2016  Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010  IBM Corporation
Copyright (C) 1999-2006  Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012  Fujitsu Limited
Copyright (C) 2006, 2007  VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011  NEC Corporation
Copyright (C) 1999, 2002, 2007  Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002  Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions.  Enter "help copying" to see the conditions.
This program has absolutely no warranty.  Enter "help warranty" for details.
 
crash: vmlinux: no .gnu_debuglink section
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu"...

      KERNEL: vmlinux                           
    DUMPFILE: vmcore
        CPUS: 12 [OFFLINE: 11]
        DATE: Tue Apr 11 12:51:15 2017
      UPTIME: 4 days, 01:31:42
LOAD AVERAGE: 0.04, 0.01, 0.00
       TASKS: 634
    NODENAME: morricone
     RELEASE: 4.11.0-rc5-default-pt+
     VERSION: #2 SMP PREEMPT Fri Apr 7 09:34:10 CEST 2017
     MACHINE: x86_64  (2400 Mhz)
      MEMORY: 16 GB
       PANIC: "sysrq: SysRq : Trigger a crash"
         PID: 19503
     COMMAND: "bash"
        TASK: ffff8803367762c0  [THREAD_INFO: ffff8803367762c0]
         CPU: 3
       STATE: TASK_RUNNING (SYSRQ)

crash> 

Petr T