libxenguest and xenguest.h

[Jürgen Groß <jgross@xxxxxxxx>]

Andy has reported a libxenguest related build failure of qemu when
building qemu outside the Xen build environment. Problem is xenguest.h
now including xenctrl_dom.h, which is including xen/libelf/libelf.h.

The underlying problem is that libxenguest is basically offering some
"official" functions via xenguest.h, while some other functions are
only Xen internally usable and are defined in xenctrl_dom.h.

This is a rather weird construction and I'm seeing the following
solutions:

1. Make xen/include/xen/libelf.h a public header (or split the parts
   needed by xenguest.h into a public header)

2. Reflect the two parts of libxenguest by carving out the xenctrl_dom.h
   defined parts into a new library not made public

3. Make the xenctrl_dom.h interfaces internal again by not adding it to
   the installed headers

While variant 3 seems to be the easiest one I'd prefer variant 1.
Variant 2 seems to add complexity without any real gain IMO.

Thoughts?


Juergen