KVM is required to run this AVD

Starting with Ubuntu 18.04 and Linux Mint Tara you need to install qemu-kvm

sudo apt install qemu-kvm

Check the ownership of /dev/kvm

ls -al /dev/kvm

Check which users are in the kvm group

grep kvm /etc/group

Output from the above command

kvm:x:some_number:

If there is nothing rightwards of the final :, there are no users in the kvm group.

To add the user your_name to the kvm group

sudo adduser your_name kvm

which adds the user to the group, and check once again with grep kvm /etc/group.

A restart may be required for the permissions to take effect.

Official answer on StackOverflow