Hi@MD,
The problem can be resolved by setting the user and group in the /etc/libvirt/libvirtd.conf configuration file as follows.
user = "nova" 
group = "nova" 
And also changing the ownership as follows.
chown -R nova:nova /var/cache/libvirt 
chown -R nova:nova /var/run/libvirt 
chown -R nova:nova /var/lib/libvirt 
Hope this will work.
Thank You