Mailing the story:
Attempt of install Xen-Unstable Dom0 via 2.6.29-rc3..
Seems like 2.6.29 will be the first vanilla kernel supporting “pv_ops” in Dom0. Base platform to start the test was Ubuntu Intrepid Server (64-bit) with Ubuntu Desktop installed via tasksel. Packages required by Xen have been installed: openssl,x11,gettext,python-devel.