Following bellow is build Xen Host on top Ubuntu 9.10 Server.It is based on direct clone via “hg” and build Xen 3.4.3-rc4 from xensource.com,applying Andrew Lyon’s 2.6.31 patch set V12 to vanilla kernel 2.6.31.12 along with tuning patched kernel via “make menuconfig” and building aka Suse xenified kernel in Ubuntu 9.10 environment.Notice that forward porting of original patch set was done by Jan Beulich for 2.6.31.8 kernel on OpenSuse 11.2.