Removing the XEN_COMPAT_030001 cruft

[Jean-Yves Migeon <jeanyves.migeon%free.fr@localhost>]

Dear all,

Now that -6 has been branched, I would like to remove the
XEN_COMPAT_030001 code that lies here and there in the source tree.

Reasons are following:
- first, it simplifies code reading by making the P2M/M2P translations
the same for dom0 and domU, without having to play with XPMAP_OFFSET
tricks for old domU images.
- it forces the use of the hypercall page. The int 0x82 for hypercalls
has disappeared with newest revision of Xen (4.0 or 4.1 if memory serves
right).
-  It allows the merge of the xpmap_mtop and the mfn_to_pfn functions in
one go, using the xen_p2m_*() API Christoph and I drafted some years ago [1]
- last but not least, all supported Linux distros out there either use a
heavily patched Xen 3.0.3 hypervisor (RHEL 5), or simply made the jump
to Xen 4 (Debian, Ubuntu, ...). 3.0.1 and down are not really maintained
any more IMHO, and should be avoided for security reasons.

Opinions?

[1] http://mail-index.netbsd.org/port-xen/2009/05/09/msg004951.html

-- 
Jean-Yves Migeon
jeanyves.migeon%free.fr@localhost