Android : ANDROID STUDIO emulator ERROR x86 emulation currently requires hardware acceleration

I am a newbie in Android am I have just installed Android Studio on my machine which runs on Ubuntu 14.04 LTS. When I try to run the virtual device I get this error

/home/james/Android/Sdk/tools/emulator -avd Nexus_5_2014_API_21 -netspeed full -netdelay none emulator: ERROR: x86 emulation currently requires hardware acceleration! Please ensure KVM is properly installed and usable. CPU acceleration status: KVM is not installed on this machine (/dev/kvm is missing).

Anyone with a solurion for this?