inventory

[foo]
hosta ansible_ssh_host=localhost kvm=kvma ansible_python_interpreter=/usr/bin/python2
hostb ansible_ssh_host=localhost kvm=kvmb ansible_python_interpreter=/usr/bin/python2

[kvm]
kvma ansible_ssh_host=localhost ansible_python_interpreter=/usr/bin/python2
kvmb ansible_ssh_host=localhost ansible_python_interpreter=/usr/bin/python2

playbook.yml

---

- hosts: foo
  serial: 1

  vars:
    snapshot_name: "MEP-{{ ansible_date_time['date'] }}-{{ ansible_date_time['time'] }}"
    kvm: "{{ hostvars[inventory_hostname]['kvm'] }}"

  tasks:
  - name: do something on the kvm hosting the vm
    shell: echo domain={{ inventory_hostname }} kvm={{ kvm }} snapshot_name={{ snapshot_name }}
    delegate_to: "{{ kvm }}"