/home/praveen/Android/Sdk/tools/emulator -avd Nexus_6_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).

kvm-ok

INFO: /dev/kvm exists
KVM acceleration can be used

INFO: Your CPU does not support KVM extensions
KVM acceleration can NOT be used

sudo apt-get install qemu-kvm libvirt-bin ubuntu-vm-builder bridge-utils

HP-EliteBook-820-G1:/opt/android-studio/bin$ sudo /usr/sbin/kvm-ok
INFO: /dev/kvm does not exist
HINT:   sudo modprobe kvm_intel
INFO: Your CPU supports KVM extensions
INFO: KVM (vmx) is disabled by your BIOS
HINT: Enter your BIOS setup and enable Virtualization Technology (VT),
      and then hard poweroff/poweron your system
KVM acceleration can NOT be used

sudo modprobe kvm_intel