Add possibility to configure HDD cache mode during instance creation

create/forms.py

@@ -40,6 +40,7 @@ class NewVMForm(forms.Form):
     storage = forms.CharField(max_length=20, required=False)
     template = forms.CharField(required=False)
     images = forms.CharField(required=False)
+    cache_mode = forms.CharField(error_messages={'required': _('Please select HDD cache mode')})
     hdd_size = forms.IntegerField(required=False)
     meta_prealloc = forms.BooleanField(required=False)
     virtio = forms.BooleanField(required=False)

create/templates/create_instance.html

@@ -77,6 +77,16 @@
                                     </select>
                                 </div>
                             </div>
+                            <div class="form-group">
+                                <label class="col-sm-3 control-label">{% trans "HDD cache mode" %}</label>
+                                <div class="col-sm-6">
+                                    <select id="cache_mode" name="cache_mode" class="form-control">
+                                        {% for mode, name in cache_modes %}
+                                            <option value="{{ mode }}">{% trans name %}</option>
+                                        {% endfor %}
+                                    </select>
+                                </div>
+                            </div>
                             <div class="form-group">
                                 <label class="col-sm-3 control-label">{% trans "Network" %}</label>
                                 <div class="col-sm-6">
@@ -159,6 +169,16 @@
                                     </div>
                                     <label class="col-lg-1 control-label">{% trans "Image" %}</label>
                                 </div>
+                                <div class="form-group">
+                                    <label class="col-sm-3 control-label">{% trans "HDD cache mode" %}</label>
+                                    <div class="col-sm-6">
+                                        <select id="cache_mode" name="cache_mode" class="form-control">
+                                            {% for mode, name in cache_modes %}
+                                                <option value="{{ mode }}">{% trans name %}</option>
+                                            {% endfor %}
+                                        </select>
+                                    </div>
+                                </div>
                                 <div class="form-group">
                                     <label class="col-sm-3 control-label">{% trans "Network" %}</label>
                                     <div class="col-sm-6">

create/views.py

@@ -42,6 +42,7 @@ def create_instance(request, compute_id):
         networks = sorted(conn.get_networks())
         instances = conn.get_instances()
         get_images = sorted(conn.get_storages_images())
+        cache_modes = sorted(conn.get_cache_modes().items())
         mac_auto = util.randomMAC()
     except libvirtError as lib_err:
         error_messages.append(lib_err)
@@ -123,11 +124,15 @@ def create_instance(request, compute_id):
                                         volumes[path] = conn.get_volume_type(path)
                                     except libvirtError as lib_err:
                                         error_messages.append(lib_err.message)
+                        if data['cache_mode'] not in conn.get_cache_modes():
+                            error_msg = _("Invalid cache mode")
+                            error_messages.append(error_msg)
                         if not error_messages:
                             uuid = util.randomUUID()
                             try:
                                 conn.create_instance(data['name'], data['memory'], data['vcpu'], data['host_model'],
-                                                     uuid, volumes, data['networks'], data['virtio'], data['mac'])
+                                                     uuid, volumes, data['cache_mode'], data['networks'], data['virtio'],
+                                                     data['mac'])
                                 create_instance = Instance(compute_id=compute_id, name=data['name'], uuid=uuid)
                                 create_instance.save()
                                 return HttpResponseRedirect(reverse('instance', args=[compute_id, data['name']]))

vrtManager/create.py

@@ -48,6 +48,17 @@ class wvmCreate(wvmConnect):
         """Get guest capabilities"""
         return util.get_xml_path(self.get_cap_xml(), "/capabilities/host/cpu/arch")
 
+    def get_cache_modes(self):
+        """Get cache available modes"""
+        return {
+            'default': 'Default',
+            'none': 'Disabled',
+            'writethrough': 'Write through',
+            'writeback': 'Write back',
+            'directsync': 'Direct sync',  # since libvirt 0.9.5
+            'unsafe': 'Unsafe',  # since libvirt 0.9.7
+        }
+
     def create_volume(self, storage, name, size, format='qcow2', metadata=False):
         size = int(size) * 1073741824
         stg = self.get_storage(storage)
@@ -129,7 +140,7 @@ class wvmCreate(wvmConnect):
         vol = self.get_volume_by_path(path)
         vol.delete()
 
-    def create_instance(self, name, memory, vcpu, host_model, uuid, images, networks, virtio, mac=None):
+    def create_instance(self, name, memory, vcpu, host_model, uuid, images, cache_mode, networks, virtio, mac=None):
         """
         Create VM function
         """
@@ -172,11 +183,11 @@ class wvmCreate(wvmConnect):
             if stg_type == 'rbd':
                 ceph_user, secret_uuid, ceph_hosts = get_rbd_storage_data(stg)
                 xml += """<disk type='network' device='disk'>
-                            <driver name='qemu' type='%s'/>
+                            <driver name='qemu' type='%s' cache='%s'/>
                             <auth username='%s'>
                                 <secret type='ceph' uuid='%s'/>
                             </auth>
-                            <source protocol='rbd' name='%s'>""" % (img_type, ceph_user, secret_uuid, image)
+                            <source protocol='rbd' name='%s'>""" % (img_type, cache_mode, ceph_user, secret_uuid, image)
                 if isinstance(ceph_hosts, list):
                     for host in ceph_hosts:
                         if host.get('port'):
@@ -189,8 +200,8 @@ class wvmCreate(wvmConnect):
                             </source>"""
             else:
                 xml += """<disk type='file' device='disk'>
-                            <driver name='qemu' type='%s'/>
+                            <driver name='qemu' type='%s' cache='%s'/>
-                            <source file='%s'/>""" % (img_type, image)
+                            <source file='%s'/>""" % (img_type, cache_mode, image)
 
             if virtio:
                 xml += """<target dev='vd%s' bus='virtio'/>""" % (disk_letters.pop(0),)