libvirt driver: set os_type to support xen hvm/pv

Generate libvirt config for xen hvm and pv guests based on instance
vm_mode. The vm_mode can be set via the vm_mode image property.

Use hvmloader for vm_mode.HVM guests. libvirt_type xen still defaults to
vm_mode.XEN (pv), to not change any behavior.

Change-Id: I5f92bedf6588ab2674d784772a5ecdb895fabe40

4 files changed, 90 insertions, 7 deletions

diff --git a/nova/tests/test_libvirt.py b/nova/tests/test_libvirt.py
index 6020d820c..0e349c8a8 100644
--- a/nova/tests/test_libvirt.py
+++ b/nova/tests/test_libvirt.py
@@ -800,6 +800,19 @@ class LibvirtConnTestCase(test.TestCase):
         self._check_xml_and_uri(instance_data,
                                 expect_kernel=False, expect_ramdisk=False)
 
+    def test_xml_and_uri_no_ramdisk_no_kernel_xen_hvm(self):
+        instance_data = dict(self.test_instance)
+        instance_data.update({'vm_mode': vm_mode.HVM})
+        self._check_xml_and_uri(instance_data, expect_kernel=False,
+                                expect_ramdisk=False, expect_xen_hvm=True)
+
+    def test_xml_and_uri_no_ramdisk_no_kernel_xen_pv(self):
+        instance_data = dict(self.test_instance)
+        instance_data.update({'vm_mode': vm_mode.XEN})
+        self._check_xml_and_uri(instance_data, expect_kernel=False,
+                                expect_ramdisk=False, expect_xen_hvm=False,
+                                xen_only=True)
+
     def test_xml_and_uri_no_ramdisk(self):
         instance_data = dict(self.test_instance)
         instance_data['kernel_id'] = 'aki-deadbeef'
@@ -1356,7 +1369,7 @@ class LibvirtConnTestCase(test.TestCase):
                          instance_ref['uuid'])
 
     def _check_xml_and_uri(self, instance, expect_ramdisk, expect_kernel,
-                           rescue=None):
+                           rescue=None, expect_xen_hvm=False, xen_only=False):
         user_context = context.RequestContext(self.user_id, self.project_id)
         instance_ref = db.instance_create(user_context, instance)
         network_ref = db.project_get_networks(context.get_admin_context(),
@@ -1379,10 +1392,22 @@ class LibvirtConnTestCase(test.TestCase):
                         'xen': ('xen:///',
                              [(lambda t: t.find('.').get('type'), 'xen'),
                               (lambda t: t.find('./os/type').text,
-                               vm_mode.XEN)]),
-                              }
+                               vm_mode.XEN)])}
+
+        if expect_xen_hvm or xen_only:
+            hypervisors_to_check = ['xen']
+        else:
+            hypervisors_to_check = ['qemu', 'kvm', 'xen']
+
+        if expect_xen_hvm:
+            type_uri_map = {}
+            type_uri_map['xen'] = ('xen:///',
+                                   [(lambda t: t.find('.').get('type'),
+                                       'xen'),
+                                    (lambda t: t.find('./os/type').text,
+                                        vm_mode.HVM)])
 
-        for hypervisor_type in ['qemu', 'kvm', 'xen']:
+        for hypervisor_type in hypervisors_to_check:
             check_list = type_uri_map[hypervisor_type][1]
 
             if rescue:
diff --git a/nova/tests/test_libvirt_config.py b/nova/tests/test_libvirt_config.py
index 55f5528c7..87c044115 100644
--- a/nova/tests/test_libvirt_config.py
+++ b/nova/tests/test_libvirt_config.py
@@ -556,7 +556,7 @@ class LibvirtConfigGuestTest(LibvirtConfigBaseTest):
               </devices>
             </domain>""")
 
-    def test_config_xen(self):
+    def test_config_xen_pv(self):
         obj = config.LibvirtConfigGuest()
         obj.virt_type = "xen"
         obj.memory = 1024 * 1024 * 100
@@ -599,6 +599,47 @@ class LibvirtConfigGuestTest(LibvirtConfigBaseTest):
               </devices>
             </domain>""")
 
+    def test_config_xen_hvm(self):
+        obj = config.LibvirtConfigGuest()
+        obj.virt_type = "xen"
+        obj.memory = 1024 * 1024 * 100
+        obj.vcpus = 2
+        obj.name = "demo"
+        obj.uuid = "b38a3f43-4be2-4046-897f-b67c2f5e0147"
+        obj.os_type = "hvm"
+        obj.os_loader = '/usr/lib/xen/boot/hvmloader'
+        obj.os_root = "root=xvda"
+        obj.os_cmdline = "console=xvc0"
+
+        disk = config.LibvirtConfigGuestDisk()
+        disk.source_type = "file"
+        disk.source_path = "/tmp/img"
+        disk.target_dev = "/dev/xvda"
+        disk.target_bus = "xen"
+
+        obj.add_device(disk)
+
+        xml = obj.to_xml()
+        self.assertXmlEqual(xml, """
+            <domain type="xen">
+              <uuid>b38a3f43-4be2-4046-897f-b67c2f5e0147</uuid>
+              <name>demo</name>
+              <memory>104857600</memory>
+              <vcpu>2</vcpu>
+              <os>
+                <type>hvm</type>
+                <loader>/usr/lib/xen/boot/hvmloader</loader>
+                <cmdline>console=xvc0</cmdline>
+                <root>root=xvda</root>
+              </os>
+              <devices>
+                <disk type="file" device="disk">
+                  <source file="/tmp/img"/>
+                  <target bus="xen" dev="/dev/xvda"/>
+                </disk>
+              </devices>
+            </domain>""")
+
     def test_config_kvm(self):
         obj = config.LibvirtConfigGuest()
         obj.virt_type = "kvm"
diff --git a/nova/virt/libvirt/config.py b/nova/virt/libvirt/config.py
index da55dc234..a53ed640f 100644
--- a/nova/virt/libvirt/config.py
+++ b/nova/virt/libvirt/config.py
@@ -575,6 +575,7 @@ class LibvirtConfigGuest(LibvirtConfigObject):
         self.acpi = False
         self.clock = None
         self.os_type = None
+        self.os_loader = None
         self.os_kernel = None
         self.os_initrd = None
         self.os_cmdline = None
@@ -594,6 +595,8 @@ class LibvirtConfigGuest(LibvirtConfigObject):
         os.append(self._text_node("type", self.os_type))
         if self.os_kernel is not None:
             os.append(self._text_node("kernel", self.os_kernel))
+        if self.os_loader is not None:
+            os.append(self._text_node("loader", self.os_loader))
         if self.os_initrd is not None:
             os.append(self._text_node("initrd", self.os_initrd))
         if self.os_cmdline is not None:
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index f0ffa895c..9fcb61c3e 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -1713,6 +1713,21 @@ class LibvirtDriver(driver.ComputeDriver):
                 nova_context.get_admin_context(), instance['uuid'],
                 {'root_device_name': '/dev/' + self.default_root_device})
 
+        guest.os_type = vm_mode.get_from_instance(instance)
+
+        if guest.os_type is None:
+            if FLAGS.libvirt_type == "lxc":
+                guest.os_type = vm_mode.EXE
+            elif FLAGS.libvirt_type == "uml":
+                guest.os_type = vm_mode.UML
+            elif FLAGS.libvirt_type == "xen":
+                guest.os_type = vm_mode.XEN
+            else:
+                guest.os_type = vm_mode.HVM
+
+        if FLAGS.libvirt_type == "xen" and guest.os_type == vm_mode.HVM:
+            guest.os_loader = '/usr/lib/xen/boot/hvmloader'
+
         if FLAGS.libvirt_type == "lxc":
             guest.os_type = vm_mode.EXE
             guest.os_init_path = "/sbin/init"
@@ -1723,7 +1738,6 @@ class LibvirtDriver(driver.ComputeDriver):
             guest.os_root = root_device_name or "/dev/ubda"
         else:
             if FLAGS.libvirt_type == "xen":
-                guest.os_type = vm_mode.XEN
                 guest.os_root = root_device_name or "/dev/xvda"
             else:
                 guest.os_type = vm_mode.HVM
@@ -1808,7 +1822,7 @@ class LibvirtDriver(driver.ComputeDriver):
             guest.add_device(consolepty)
 
         if FLAGS.vnc_enabled and FLAGS.libvirt_type not in ('lxc', 'uml'):
-            if FLAGS.use_usb_tablet:
+            if FLAGS.use_usb_tablet and guest.os_type == vm_mode.HVM:
                 tablet = config.LibvirtConfigGuestInput()
                 tablet.type = "tablet"
                 tablet.bus = "usb"