Merge "libvirt: implements boot from ISO images"

3 files changed, 55 insertions, 22 deletions

diff --git a/nova/tests/test_libvirt.py b/nova/tests/test_libvirt.py
index 92a14ee2a..15b7f7259 100644
--- a/nova/tests/test_libvirt.py
+++ b/nova/tests/test_libvirt.py
@@ -347,12 +347,12 @@ class LibvirtConnTestCase(test.TestCase):
 
         result = conn._prepare_xml_info(instance_ref,
                                         _fake_network_info(self.stubs, 1),
-                                        False)
+                                        None, False)
         self.assertTrue(len(result['nics']) == 1)
 
         result = conn._prepare_xml_info(instance_ref,
                                         _fake_network_info(self.stubs, 2),
-                                        False)
+                                        None, False)
         self.assertTrue(len(result['nics']) == 2)
 
     def test_xml_and_uri_no_ramdisk_no_kernel(self):
@@ -394,6 +394,14 @@ class LibvirtConnTestCase(test.TestCase):
         instance_data = dict(self.test_instance)
         self._check_xml_and_disk_prefix(instance_data)
 
+    def test_xml_disk_bus_virtio(self):
+        self._check_xml_and_disk_bus({"disk_format": "raw"},
+                                     "disk", "virtio")
+
+    def test_xml_disk_bus_ide(self):
+        self._check_xml_and_disk_bus({"disk_format": "iso"},
+                                     "cdrom", "ide")
+
     @test.skip_if(missing_libvirt(), "Test requires libvirt")
     def test_snapshot_in_ami_format(self):
         self.flags(image_service='nova.image.fake.FakeImageService')
@@ -555,7 +563,7 @@ class LibvirtConnTestCase(test.TestCase):
         network_info = _fake_network_info(self.stubs, 2)
         conn = connection.LibvirtConnection(True)
         instance_ref = db.instance_create(self.context, instance_data)
-        xml = conn.to_xml(instance_ref, network_info, False)
+        xml = conn.to_xml(instance_ref, network_info, None, False)
         tree = xml_to_tree(xml)
         interfaces = tree.findall("./devices/interface")
         self.assertEquals(len(interfaces), 2)
@@ -627,6 +635,19 @@ class LibvirtConnTestCase(test.TestCase):
                                  '%s != %s failed check %d' %
                                  (check(tree), expected_result, i))
 
+    def _check_xml_and_disk_bus(self, image_meta, device_type, bus):
+        user_context = context.RequestContext(self.user_id, self.project_id)
+        instance_ref = db.instance_create(user_context, self.test_instance)
+        network_info = _fake_network_info(self.stubs, 1)
+
+        xml = connection.LibvirtConnection(True).to_xml(instance_ref,
+                                                        network_info,
+                                                        image_meta)
+        tree = xml_to_tree(xml)
+        self.assertEqual(tree.find('./devices/disk').get('device'),
+                         device_type)
+        self.assertEqual(tree.find('./devices/disk/target').get('bus'), bus)
+
     def _check_xml_and_uri(self, instance, expect_ramdisk, expect_kernel,
                            rescue=False):
         user_context = context.RequestContext(self.user_id, self.project_id)
@@ -708,7 +729,7 @@ class LibvirtConnTestCase(test.TestCase):
             self.assertEquals(conn.uri, expected_uri)
 
             network_info = _fake_network_info(self.stubs, 1)
-            xml = conn.to_xml(instance_ref, network_info, rescue)
+            xml = conn.to_xml(instance_ref, network_info, None, rescue)
             tree = xml_to_tree(xml)
             for i, (check, expected_result) in enumerate(checks):
                 self.assertEqual(check(tree),
diff --git a/nova/virt/libvirt.xml.template b/nova/virt/libvirt.xml.template
index 2a01f32b7..8cf361ef7 100644
--- a/nova/virt/libvirt.xml.template
+++ b/nova/virt/libvirt.xml.template
@@ -3,23 +3,29 @@
     <memory>${memory_kb}</memory>
     <os>
 #if $type == 'lxc'
-    #set $disk_bus = ''
         <type>exe</type>
         <init>/sbin/init</init>
 #else if $type == 'uml'
-    #set $disk_bus = 'uml'
+    #set $root_disk_bus = 'uml'
+    #set $ephemeral_disk_bus = 'uml'
         <type>uml</type>
         <kernel>/usr/bin/linux</kernel>
         #set $root_device_name = $getVar('root_device_name', '/dev/ubda')
         <root>${root_device_name}</root>
 #else
     #if $type == 'xen'
-        #set $disk_bus = 'scsi'
+        #set $root_disk_bus = 'scsi'
+        #set $ephemeral_disk_bus = 'scsi'
             <type>linux</type>
             #set $root_device_name = $getVar('root_device_name', '/dev/xvda')
             <root>${root_device_name}</root>
     #else
-        #set $disk_bus = 'virtio'
+        #set $ephemeral_disk_bus = 'virtio'
+        #if $root_device_type == 'cdrom'
+            #set $root_disk_bus = 'ide'
+        #else
+            #set $root_disk_bus = 'virtio'
+        #end if
             <type>hvm</type>
     #end if
     #if $getVar('rescue', False)
@@ -58,40 +64,40 @@
         <disk type='file'>
             <driver type='${driver_type}'/>
             <source file='${basepath}/disk.rescue'/>
-            <target dev='${disk_prefix}a' bus='${disk_bus}'/>
+            <target dev='${disk_prefix}a' bus='${ephemeral_disk_bus}'/>
         </disk>
         <disk type='file'>
             <driver type='${driver_type}'/>
             <source file='${basepath}/disk'/>
-            <target dev='${disk_prefix}b' bus='${disk_bus}'/>
+            <target dev='${disk_prefix}b' bus='${ephemeral_disk_bus}'/>
         </disk>
     #else
         #if not ($getVar('ebs_root', False))
-        <disk type='file'>
+        <disk type='file' device='${root_device_type}'>
             <driver type='${driver_type}'/>
             <source file='${basepath}/disk'/>
-            <target dev='${root_device}' bus='${disk_bus}'/>
+            <target dev='${root_device}' bus='${root_disk_bus}'/>
         </disk>
         #end if
         #if $getVar('local_device', False)
             <disk type='file'>
                 <driver type='${driver_type}'/>
                 <source file='${basepath}/disk.local'/>
-                <target dev='${local_device}' bus='${disk_bus}'/>
+                <target dev='${local_device}' bus='${ephemeral_disk_bus}'/>
             </disk>
         #end if
         #for $eph in $ephemerals
          <disk type='block'>
                 <driver type='${driver_type}'/>
                 <source dev='${basepath}/${eph.device_path}'/>
-                <target dev='${eph.device}' bus='${disk_bus}'/>
+                <target dev='${eph.device}' bus='${ephemeral_disk_bus}'/>
          </disk>
         #end for
         #if $getVar('swap_device', False)
             <disk type='file'>
                 <driver type='${driver_type}'/>
                 <source file='${basepath}/disk.swap'/>
-                <target dev='${swap_device}' bus='${disk_bus}'/>
+                <target dev='${swap_device}' bus='${ephemeral_disk_bus}'/>
             </disk>
         #end if
         #for $vol in $volumes
@@ -102,7 +108,7 @@
         <disk type='file'>
             <driver type='raw' />
             <source file='${basepath}/disk.config' />
-            <target dev='${disk_prefix}z' bus='${disk_bus}' />
+            <target dev='${disk_prefix}z' bus='${ephemeral_disk_bus}' />
         </disk>
     #end if
 #end if
diff --git a/nova/virt/libvirt/connection.py b/nova/virt/libvirt/connection.py
index 096bf2922..c1870261d 100644
--- a/nova/virt/libvirt/connection.py
+++ b/nova/virt/libvirt/connection.py
@@ -629,7 +629,7 @@ class LibvirtConnection(driver.ComputeDriver):
                                          'unrescue.xml')
         libvirt_utils.write_to_file(unrescue_xml_path, unrescue_xml)
 
-        xml = self.to_xml(instance, network_info, rescue=True)
+        xml = self.to_xml(instance, network_info, image_meta, rescue=True)
         rescue_images = {
             'image_id': FLAGS.rescue_image_id or instance['image_ref'],
             'kernel_id': FLAGS.rescue_kernel_id or instance['kernel_id'],
@@ -671,7 +671,7 @@ class LibvirtConnection(driver.ComputeDriver):
     @exception.wrap_exception()
     def spawn(self, context, instance, image_meta, network_info,
               block_device_info=None):
-        xml = self.to_xml(instance, network_info, False,
+        xml = self.to_xml(instance, network_info, image_meta, False,
                           block_device_info=block_device_info)
         self.firewall_driver.setup_basic_filtering(instance, network_info)
         self.firewall_driver.prepare_instance_filter(instance, network_info)
@@ -1086,7 +1086,7 @@ class LibvirtConnection(driver.ComputeDriver):
         LOG.debug(_("block_device_list %s"), block_device_list)
         return block_device.strip_dev(mount_device) in block_device_list
 
-    def _prepare_xml_info(self, instance, network_info, rescue,
+    def _prepare_xml_info(self, instance, network_info, image_meta, rescue,
                           block_device_info=None):
         block_device_mapping = driver.block_device_info_get_mapping(
             block_device_info)
@@ -1103,6 +1103,11 @@ class LibvirtConnection(driver.ComputeDriver):
         else:
             driver_type = 'raw'
 
+        if image_meta and image_meta.get('disk_format') == 'iso':
+            root_device_type = 'cdrom'
+        else:
+            root_device_type = 'disk'
+
         volumes = []
         for vol in block_device_mapping:
             connection_info = vol['connection_info']
@@ -1139,6 +1144,7 @@ class LibvirtConnection(driver.ComputeDriver):
                     'rescue': rescue,
                     'disk_prefix': self._disk_prefix,
                     'driver_type': driver_type,
+                    'root_device_type': root_device_type,
                     'vif_type': FLAGS.libvirt_vif_type,
                     'nics': nics,
                     'ebs_root': ebs_root,
@@ -1194,12 +1200,12 @@ class LibvirtConnection(driver.ComputeDriver):
             xml_info['disk'] = xml_info['basepath'] + "/disk"
         return xml_info
 
-    def to_xml(self, instance, network_info, rescue=False,
+    def to_xml(self, instance, network_info, image_meta=None, rescue=False,
                block_device_info=None):
         # TODO(termie): cache?
         LOG.debug(_('instance %s: starting toXML method'), instance['name'])
-        xml_info = self._prepare_xml_info(instance, network_info, rescue,
-                                          block_device_info)
+        xml_info = self._prepare_xml_info(instance, network_info, image_meta,
+                                          rescue, block_device_info)
         xml = str(Template(self.libvirt_xml, searchList=[xml_info]))
         LOG.debug(_('instance %s: finished toXML method'), instance['name'])
         return xml