Look in /proc/cpuinfo and look at flags. The lm flag means the CPU is in 64bit mode.
The vmx flag means virtualisation is enabled on an Intel CPU.
The svm flag means virtualisation is enabled on an AMD CPU.
The aes flag means hardware AES is avaiable.
So
grep -q -E 'vtx|svm' /proc/cpuinfo && echo "Virtualisation enabled£