[Crash-utility] Re: crash with Xen dom0 image from kdump

[Kazuo Moriwaka]

Hello Dave,
# I append crash-utility list to Cc

From: Dave Anderson <anderson at redhat.com>
Subject: Re: crash with Xen dom0 image from kdump
Date: Thu, 01 Jun 2006 08:39:01 -0400

> Kazuo Moriwaka wrote:
> 
> > Hello,
> >
> > From: Dave Anderson <anderson at redhat.com>
> > Subject: Re: crash with Xen dom0 image from kdump
> > Date: Wed, 31 May 2006 16:20:15 -0400
> >
> > >
> > > Hey guys,
> > >
> > > I've got the vmcore file from which Kazuo generated the
> > > "simulated" xendump dumpfile.  I have a question regarding
> > > the makeup of the the vmcore file -- are the physical addresses
> > > referred to by each PT_LOAD segment based upon:
> > >
> > > 1. machine addresses, or
> > > 2. pseudo-physical addresses as perceived by the dom0 vmlinux kernel?
> > >
> > > Dave
> >
> > It's 1.
> > vmcore is made by kexec-ed linux kernel (not on xen, but on machine) kdump.
> > The kernel doesn't know about xen or domains except register info.
> > Register info is for dom0.
> >
> 
> Ok, good...
> 
> Next question -- how did you find dom0's phys_to_machine_mapping[]
> array from the vmcore in order to create the xendump?

I use xen executable binary with symbols to find 'dom0' global symbol
in xen.
In x86_32 arch, dom0->vcpu[0].arch->guest_table has pagetable address
for domain0 guest kernel.  
After it, I found 'phys_to_machine_mapping'.  
For other domains, 'domain_list' is point list of struct domain.

I'll attach my latest dom0cut script.  'dom0cut_x86_32.py' contains
names of symbols and structs to get dom0 image.

> > p.s.
> > Do you have any plan to support xen hypervisor itself with crash?
> > If there's, I want to help it.
> >
> 
> I don't -- at least at this time.  (My next primary task is to get crash
> working with x86 PAE kernels.)
> 
> But it would be an interesting project
> to undertake.  I'm not sure whether or how it would cleanly fit into
> the crash source code, or whether it should be an executable of
> its own.  But by all means, if you want to undertake the task, be
> my guest!

I'm also not sure about them, yet.  In anyway, at first, I'll help you to
support xen's vmcore format.  
It is also a part of a way to support xen hypervisor.

regards,
-- 
Kazuo Moriwaka <moriwaka at valinux.co.jp>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dom0cut.tar.gz
Type: application/octet-stream
Size: 13890 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/crash-utility/attachments/20060602/3d8f65c3/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: libelf-0.1.0.tar.gz
Type: application/octet-stream
Size: 12124 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/crash-utility/attachments/20060602/3d8f65c3/attachment-0001.obj>