Hi,
 Is NT_XEN_DOM0_CR3 not being used by x86_64 by mistake,
 or on purpose?  Or perhaps you're saying that it's going to be
 pulled out completely? 
I'm afraid it may be deleted while patch-cleaning process..
 > I know you don't want to treat xen binary file with crash,
but I'm
 > not clear why.  Please discuss with him directly to make up xen kdump
 > file formats.  The patch will be merged into xen-3.0.4.
 > I hope we can find solution before merge.
 >
 
 The crash utility is wholly based upon the internal structure
 of the Linux kernel. 
Yes, I think so.  I (and Magnus) are not clean about mismatch factor for
getting 'idle_pg_table' and
'dom0->shared_info->pfn_to_mfn_frame_list_list'
from xen binary in crash is_netdump routine. 
I think appealing this terribleness may help keep ELF Core headers.
Thanks,
-- 
Kazuo Moriwaka <moriwaka(a)valinux.co.jp>