KVM is required to run this AVD. Unknown Error! Please file a bug against Android Studio
Changed permissions in the /home/folder/Android/Sdk/emulator/ folder
chmod 777 -R /home/folder/Android/Sdk/emulator/
I also had this problem, and was able to fix it by using:
sudo chmod 777 /dev/kvm
In my case the error was because the user has not enough permission to /dev/kvm.So the solution is giving permission,i.e.,
chmod 777 /dev/kvm