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

Hello Dave, # I append crash-utility list to Cc From: Dave Anderson <anderson(a)redhat.com&gt; 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(a)redhat.com&gt; > > 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(a)valinux.co.jp&gt;