# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

---
- name: Detect the virtualisation engine
  block:
    - name: Load the kvm kernel module
      modprobe:
        name: kvm
      become: true
      failed_when: false

    - name: Check for the KVM device
      stat:
        path: /dev/kvm
      register: stat_kvm

    - name: Set a fact containing the virtualisation engine
      set_fact:
        libvirt_vm_engine: >-
          {%- if ansible_architecture != libvirt_vm_arch -%}
          {# Virtualisation instructions are generally available only for the host
          architecture. Ideally we would test for virtualisation instructions, eg. vt-d
          as it is possible that another architecture could support these even
          if the emulated cpu architecture is not the same. #}
          qemu
          {%- elif stat_kvm.stat.exists -%}
          kvm
          {%- else -%}
          qemu
          {%- endif -%}
  when: libvirt_vm_engine is none or libvirt_vm_engine | length == 0

- name: Detect the virtualisation emulator
  block:
    - block:
        - name: Detect the KVM emulator binary path
          stat:
            path: "{{ item }}"
          register: kvm_emulator_result
          with_items:
            - /usr/bin/kvm
            - /usr/bin/qemu-kvm
            - /usr/libexec/qemu-kvm

        - name: Set a fact containing the KVM emulator binary path
          set_fact:
            libvirt_vm_emulator: "{{ item.item }}"
          with_items: "{{ kvm_emulator_result.results }}"
          when: item.stat.exists
      when: libvirt_vm_engine == 'kvm'

    - block:
        - name: Detect the QEMU emulator binary path
          shell: which qemu-system-{{ libvirt_vm_arch }}
          register: qemu_emulator_result
          changed_when: false

        - name: Set a fact containing the QEMU emulator binary path
          set_fact:
            libvirt_vm_emulator: "{{ qemu_emulator_result.stdout }}"
      when: libvirt_vm_engine == 'qemu'

    - name: Fail if unable to detect the emulator
      fail:
        msg: Unable to detect emulator for engine {{ libvirt_vm_engine }}.
      when: libvirt_vm_emulator is none
  when: libvirt_vm_emulator is none or libvirt_vm_emulator | length == 0