Hi Dave,
The attached patch enables to analyze dom0 linux from
whole memory dump on IA64. (for crash-4.0-4.1)
It is just quick hack.
(I was asked from IA64 Xen developers and made it.)
Each domain manages own machine memory by domain.arch.mm.pgd
in IA64. It is 3-level page table.
I thougnt the mfn of domain.arch.mm.pgd can be regarded as
p2m_mfn.
I intended to modify as less existent code as possible.
But this patch is a bit tricky. And the memory usage is
large if the machine memory layout is sparse.
(maybe xen_kdump_p2m should be prepare for each arch ?)
Would you consider to support dom0 analysis for IA64 ?
I prepared two sample dumps. Please find from the following
URLs.
1)
http://people.valinux.co.jp/~oda/20070510-sample-dump-1.tar
contents:
- vmcore.gz
This is taken by a hard assist dump. netdump style ELF vmcore.
So XEN_ELFNOTE_CRASH_INFO does not exist.
- vmcore.ka.gz
It is coverted to kdump style and added XEN_ELFNOTE_CRASH_INFO
manually.
- vmlinux.debug.gz
for dom0 analysis
- xen-syms-2.6.18-8.el5.gz
for xencrash
To get p2m_mfn, xencrash's doms command is usefull.
--------------------------------------------------------------------------
# crash xen-syms-2.6.18-8.el5 vmcore
...
crash> doms
DID DOMAIN ST T MAXPAGE TOTPAGE VCPU SHARED_I P2M_MFN
32753 f000000007ac8080 RU O 0 0 0 0 ----
32754 f000000007acc080 RU X 0 0 0 0 ----
32767 f000000007ff8080 RU I 0 0 4 0
----
0 f000000007aa4080 RU 0 10000 fc28 1 f000000007a88000
1abb7
* 1 f000000007a78080 RU U 10603 10603 3 f000000007a5c000
1a909
crash>
----------------------------------------------------------------------------
Then normal crash session with --p2m_mfn option.
----------------------------------------------------------------------------
# crash --p2m_mfn=1abb7 vmlinux.debug vmcore
...
----------------------------------------------------------------------------
vmcore.ka has XEN_ELFNOTE_CRASH_INFO. so --p2m_mfn option not need.
----------------------------------------------------------------------------
# crash vmlinux.debug vmcore.ka
...
----------------------------------------------------------------------------
--p2m_mfn option is effective only if a vmcore has XEN_ELFNOTE_CRASH_INFO
now.
I think specifying --p2m_mfn option is regarded as the vmcore is
XEN_CORE_DUMPFILE(). The patch supports this.
I think it is necessary for dumps which does not have
XEN_ELFNOTE_CRASH_INFO such as above sample.
2)
http://people.valinux.co.jp/~oda/20070510-sample-dump-2.tar
contents:
- vmcore.tiger.iomem_machine.gz
taken by Xen kdump
- vmlinux-xen-ia64.bz2
- xen-syms-ia64.bz2
I asked Xen kdump developper (simon@valinux) to add "p2m_mfn" to
XEN_ELFNOTE_CRASH_INFO.
So this change of Xen kdump is not open yet.
If this is OK for crash, it will be commited.
Thanks.
--
Itsuro ODA <oda(a)valinux.co.jp>