The Xen driver supports running instances in PV or HVM modes, but the method it uses to determine which to use is complicated and doesn't work in all cases. The result is that images that need to use HVM mode (such as FreeBSD 64-bit) end up setting a property named 'os' set to 'windows'.

This branch adds checks for a new property called 'vm_mode'. This can be set to 'pv' or 'hvm' and select the appropriate mode. If the property doesn't exist, the existing logic is still used to determine which mode to use.

1 files changed, 18 insertions, 3 deletions

diff --git a/nova/virt/xenapi/vmops.py b/nova/virt/xenapi/vmops.py
index c6d2b0936..d105cf300 100644
--- a/nova/virt/xenapi/vmops.py
+++ b/nova/virt/xenapi/vmops.py
@@ -160,9 +160,24 @@ class VMOps(object):
         # Create the VM ref and attach the first disk
         first_vdi_ref = self._session.call_xenapi('VDI.get_by_uuid',
                 vdis[0]['vdi_uuid'])
-        use_pv_kernel = VMHelper.determine_is_pv(self._session,
-                instance.id, first_vdi_ref, disk_image_type,
-                instance.os_type)
+
+        vm_mode = instance.vm_mode and instance.vm_mode.lower()
+        if vm_mode == 'pv':
+            use_pv_kernel = True
+        elif vm_mode in ('hv', 'hvm'):
+            use_pv_kernel = False
+            vm_mode = 'hvm'  # Normalize
+        else:
+            use_pv_kernel = VMHelper.determine_is_pv(self._session,
+                    instance.id, first_vdi_ref, disk_image_type,
+                    instance.os_type)
+            vm_mode = use_pv_kernel and 'pv' or 'hvm'
+
+        if instance.vm_mode != vm_mode:
+            # Update database with normalized (or determined) value
+            db.instance_update(context.get_admin_context(),
+                               instance['id'], {'vm_mode': vm_mode})
+
         vm_ref = VMHelper.create_vm(self._session, instance,
                 kernel, ramdisk, use_pv_kernel)
         VMHelper.create_vbd(session=self._session, vm_ref=vm_ref,