Hi All. Following has been done : 1. "sudo apt-get install virt-manager" Above installed all packages required for libvirt/kvm/qemu via apt, and a vm was setup successfully. Also, the vm booting works fine, when the green start-button of virt-manager is clicked. 2. Next, qemu was compiled from sources, and only and only the following was replaced, as : "sudo cp build/qemu-system-x86_64 /usr/bin/qemu-system-x86_64" 3. Now, if the green-button on the virt-manager is clicked, following error is seen : ########################################################## Please use server=on instead qemu-system-x86_64: -chardev socket,id=charmonitor,fd=31,server,nowait: warning: short-form boolean option 'nowait' deprecated Please use wait=off instead qemu-system-x86_64: -spice port=5900,addr=127.0.0.1,disable-ticketing,image-compression=off,seamless-migration=on: warning: short-form boolean option 'disable-ticketing' deprecated Please use disable-ticketing=on instead ########################################################## So, what are the minimum libvirt modules that need to be replaced, so that upon booting up, the kvm-xml is converted to qemu-native in the latest qemu-compatible format? Thanks and Regards, Ajay