diff -ur ganeti-2.9.3/lib/constants.py ganeti-2.9.3-devmodel/lib/constants.py
--- ganeti-2.9.3/lib/constants.py	2014-01-27 10:20:35.000000000 +0100
+++ ganeti-2.9.3-devmodel/lib/constants.py	2014-02-12 19:55:47.569588274 +0100
@@ -913,6 +913,8 @@
 HV_USB_MOUSE = "usb_mouse"
 HV_KEYMAP = "keymap"
 HV_DEVICE_MODEL = "device_model"
+HV_DEVICE_MODEL_VERSION = "device_model_version"
+HV_DEVICE_MODEL_OVERRIDE = "device_model_override"
 HV_INIT_SCRIPT = "init_script"
 HV_MIGRATION_PORT = "migration_port"
 HV_MIGRATION_BANDWIDTH = "migration_bandwidth"
@@ -988,6 +990,8 @@
   HV_USB_MOUSE: VTYPE_STRING,
   HV_KEYMAP: VTYPE_STRING,
   HV_DEVICE_MODEL: VTYPE_STRING,
+  HV_DEVICE_MODEL_VERSION: VTYPE_STRING,
+  HV_DEVICE_MODEL_OVERRIDE: VTYPE_STRING,
   HV_INIT_SCRIPT: VTYPE_STRING,
   HV_MIGRATION_PORT: VTYPE_INT,
   HV_MIGRATION_BANDWIDTH: VTYPE_INT,
@@ -2086,6 +2090,8 @@
     HV_PAE: True,
     HV_KERNEL_PATH: "/usr/lib/xen/boot/hvmloader",
     HV_DEVICE_MODEL: "/usr/lib/xen/bin/qemu-dm",
+    HV_DEVICE_MODEL_VERSION: "",
+    HV_DEVICE_MODEL_OVERRIDE: "",
     HV_MIGRATION_PORT: 8002,
     HV_MIGRATION_MODE: HT_MIGRATION_NONLIVE,
     HV_USE_LOCALTIME: False,
diff -ur ganeti-2.9.3/lib/hypervisor/hv_xen.py ganeti-2.9.3-devmodel/lib/hypervisor/hv_xen.py
--- ganeti-2.9.3/lib/hypervisor/hv_xen.py	2014-02-12 20:02:01.476840082 +0100
+++ ganeti-2.9.3-devmodel/lib/hypervisor/hv_xen.py	2014-02-12 20:01:05.332918224 +0100
@@ -1130,6 +1130,8 @@
        "VNC bind address is not a valid IP address", None, None),
     constants.HV_KERNEL_PATH: hv_base.REQ_FILE_CHECK,
     constants.HV_DEVICE_MODEL: hv_base.REQ_FILE_CHECK,
+    constants.HV_DEVICE_MODEL_VERSION: hv_base.NO_CHECK,
+    constants.HV_DEVICE_MODEL_OVERRIDE: hv_base.NO_CHECK,
     constants.HV_VNC_PASSWORD_FILE: hv_base.REQ_FILE_CHECK,
     constants.HV_MIGRATION_PORT: hv_base.REQ_NET_PORT_CHECK,
     constants.HV_MIGRATION_MODE: hv_base.MIGRATION_MODE_CHECK,
@@ -1194,6 +1196,10 @@
 
     config.write("apic = 1\n")
     config.write("device_model = '%s'\n" % hvp[constants.HV_DEVICE_MODEL])
+    if hvp[constants.HV_DEVICE_MODEL_VERSION]:
+      config.write("device_model_version = '%s'\n" % hvp[constants.HV_DEVICE_MODEL_VERSION])
+    if hvp[constants.HV_DEVICE_MODEL_OVERRIDE]:
+      config.write("device_model_override = '%s'\n" % hvp[constants.HV_DEVICE_MODEL_OVERRIDE])
     config.write("boot = '%s'\n" % hvp[constants.HV_BOOT_ORDER])
     config.write("sdl = 0\n")
     config.write("usb = 1\n")