So, you wanna install KVM on CentOS7. First we want to check if the instruction set for the cpu supports virtualisation emulation. This is important for great performance but in the case it is missing.
$ egrep -c '(vmx|svm)' /proc/cpuinfo 2
If the result comes back 0, you don’t have it!
sudo yum install kvm virt-manager libvirt virt-install qemu-kvm xauth dejavu-lgc-sans-fonts