[libvirt] hellolibvirt: no hypervisor driver available for xen:///

Hi, I downloaded and built the latest libvirt source code 0.8. I installed the library in a custom directory libvirt-0.8.0-install/ keeping all other configurations default. After this I tried to execute the example hellolibvirt: [hellolibvirt]# ./hellolibvirt xen Attempting to connect to hypervisor libvir: Remote error : unable to connect to '/root/ganeshp/libvirt-0.8.0-install/var/run/libvirt/libvirt-sock', libvirtd may need to be started: Connection refused No connection to hypervisor Parameter error when attempting to get last error My libvirtd was running from /etc/init.d/libvirtd. Still why is it trying to connect to the newly built libvirtd? I stopped the /etc/init.d/libvirtd and started my newly built daemon: [hellolibvirt]# /root/ganeshp/libvirt-0.8.0-install/sbin/libvirtd start & 04:47:07.534: warning : qemudStartup:1574 : Unable to create cgroup for driver: No such device or address 04:47:07.540: error : parse_socket:126 : cannot open /sys/devices/system/cpu/cpu1/topology/physical_package_id: No such file or directory 04:47:07.540: warning : qemudCapsInit:1068 : Failed to get host CPU 04:47:07.544: warning : lxcStartup:1835 : Unable to create cgroup for driver: No such device or address After this I tried running hellolibvirt example again: [hellolibvirt]# ./hellolibvirt xen Attempting to connect to hypervisor 04:48:43.166: error : virLibConnError:450 : no hypervisor driver available for xen:/// libvir: error : no hypervisor driver available for xen:/// libvir: error : no hypervisor driver available for xen:/// No connection to hypervisor Parameter error when attempting to get last error I do not understand why the program is not able to find the xen driver. I am able to launch VMM GUI and create VMs using xen connection. The system already has xen hypervisor (3.1.0). Even the newly built virsh gives similar errors. Whereas /usr/bin/virsh works perfectly fine. Am I missing some configuration or dependency? Any pointers/suggestion would greatly help. Thanks. Regards, -Ganesh