Init is probably statically linked against your C library (in this case
glibc). Your version of init was not built against Xen friendly libc,
hence you see this warning every time init runs.
I have libc6-xen installed already, however, the xen friendly library is not statically
linked by init according to your explanation. How should it be?
The reason that disabling tls did not make it go away is because init is
not loading those shared objects. Your better off installing libc-xen
and recompiling init.
I don't know much about this. How should libc-xen be properly used as an
substitute of libc in face of libc's being.