Add VM machine and CPU mode support

Machine default is pc-1.0. Perhaps this should be none by default?

Mode default is 'host-passthrough' for KVM, 'host-model' otherwise.

Author: markgoddard

README.md

@@ -29,6 +29,12 @@ attempt to auto-detect the correct emulator to use.
 
 `libvirt_vm_arch`: CPU architecture, default is `x86_64`.
 
+`libvirt_vm_machine`: Virtual machine type. Default is `None` if
+`libvirt_vm_engine` is `kvm`, otherwise `pc-1.0`.
+
+`libvirt_vm_cpu_mode`: Virtual machine CPU mode. Default is `host-passthrough`
+if `libvirt_vm_engine` is `kvm`, otherwise `host-model`.
+
 `libvirt_vm_volumes`: a list of volumes to attach to the VM.  Each volume is
 defined with the following dict:
 - `name`: Name to associate with the volume being created.

defaults/main.yml

@@ -22,6 +22,12 @@ libvirt_vm_emulator:
 # CPU architecture.
 libvirt_vm_arch: x86_64
 
+# Virtual machine type.
+libvirt_vm_machine: "{{ None if libvirt_vm_engine == 'kvm' else 'pc-1.0' }}"
+
+# Virtual machine CPU mode.
+libvirt_vm_cpu_mode: "{{ 'host-passthrough' if libvirt_vm_engine == 'kvm' else 'host-model' }}"
+
 # List of volumes.
 libvirt_vm_volumes: []
 

templates/vm.xml.j2

@@ -4,11 +4,11 @@
   <vcpu>{{ libvirt_vm_vcpus }}</vcpu>
   <clock sync="localtime"/>
   <os>
-    <type arch='{{ libvirt_vm_arch }}'>hvm</type>
+    <type arch='{{ libvirt_vm_arch }}'{% if libvirt_vm_machine is not none %} machine='{{ libvirt_vm_machine }}'{% endif %}>hvm</type>
   </os>
-  {% if libvirt_vm_engine == 'kvm' %}
-  <cpu mode='host-passthrough'/>
-  {% endif %}
+  <cpu{% if libvirt_vm_cpu_mode is not none %} mode='{{ libvirt_vm_cpu_mode }}'{% endif %}>
+    <model fallback='allow'/>
+  </cpu>
   <devices>
     <emulator>{{ libvirt_vm_emulator }}</emulator>
 {% for volume in libvirt_vm_volumes %}