Index: xen-unstable.hg/tools/python/xen/lowlevel/xc/xc.c
===================================================================
--- xen-unstable.hg.orig/tools/python/xen/lowlevel/xc/xc.c	2008-04-04 13:01:00.000000000 -0400
+++ xen-unstable.hg/tools/python/xen/lowlevel/xc/xc.c	2008-04-04 13:45:08.000000000 -0400
@@ -622,14 +622,14 @@
     int i;
 #endif
     char *image;
-    int memsize, vcpus = 1, acpi = 0, apic = 1;
+    int memsize, vcpus = 1, acpi = 0, apic = 1, extid = 0;
 
     static char *kwd_list[] = { "domid",
-				"memsize", "image", "vcpus", "acpi",
+				"memsize", "image", "vcpus", "extid", "acpi",
 				"apic", NULL };
-    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "iis|iii", kwd_list,
+    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "iis|iiii", kwd_list,
                                       &dom, &memsize,
-                                      &image, &vcpus, &acpi, &apic) )
+                                      &image, &vcpus, &extid, &acpi, &apic) )
         return NULL;
 
     if ( xc_hvm_build(self->xc_handle, dom, memsize, image) != 0 )
@@ -654,6 +654,7 @@
     va_hvm->checksum = -sum;
     munmap(va_map, XC_PAGE_SIZE);
 #endif
+    xc_set_hvm_param(self->xc_handle, dom, HVM_PARAM_EXTEND_HYPERVISOR, extid);
 
     return Py_BuildValue("{}");
 }
Index: xen-unstable.hg/tools/python/xen/xend/XendConfig.py
===================================================================
--- xen-unstable.hg.orig/tools/python/xen/xend/XendConfig.py	2008-04-04 13:01:01.000000000 -0400
+++ xen-unstable.hg/tools/python/xen/xend/XendConfig.py	2008-04-04 13:56:58.000000000 -0400
@@ -139,6 +139,7 @@
     'monitor': int,
     'nographic': int,
     'pae' : int,
+    'extid': int, 
     'rtc_timeoffset': int,
     'serial': str,
     'sdl': int,
Index: xen-unstable.hg/tools/python/xen/xend/image.py
===================================================================
--- xen-unstable.hg.orig/tools/python/xen/xend/image.py	2008-04-04 13:01:01.000000000 -0400
+++ xen-unstable.hg/tools/python/xen/xend/image.py	2008-04-04 13:45:08.000000000 -0400
@@ -508,6 +508,7 @@
 
         self.apic = int(vmConfig['platform'].get('apic', 0))
         self.acpi = int(vmConfig['platform'].get('acpi', 0))
+	self.extid  = int(vmConfig['platform'].get('extid',  0))
         self.guest_os_type = vmConfig['platform'].get('guest_os_type')
 
     # Return a list of cmd line args to the device models based on the
@@ -607,6 +608,7 @@
         log.debug("store_evtchn   = %d", store_evtchn)
         log.debug("memsize        = %d", mem_mb)
         log.debug("vcpus          = %d", self.vm.getVCpuCount())
+	log.debug("extid          = %d", self.extid)
         log.debug("acpi           = %d", self.acpi)
         log.debug("apic           = %d", self.apic)
 
@@ -614,6 +616,7 @@
                           image          = self.loader,
                           memsize        = mem_mb,
                           vcpus          = self.vm.getVCpuCount(),
+			  extid          = self.extid,
                           acpi           = self.acpi,
                           apic           = self.apic)
         rc['notes'] = { 'SUSPEND_CANCEL': 1 }
Index: xen-unstable.hg/tools/python/xen/xm/create.py
===================================================================
--- xen-unstable.hg.orig/tools/python/xen/xm/create.py	2008-04-04 13:01:01.000000000 -0400
+++ xen-unstable.hg/tools/python/xen/xm/create.py	2008-04-04 13:45:08.000000000 -0400
@@ -207,6 +207,10 @@
           use="""Timer mode (0=delay virtual time when ticks are missed;
           1=virtual time is always wallclock time.""")
 
+gopts.var('extid', val='EXTID',
+          fn=set_int, default=0,
+          use="Specify extention ID for a HVM domain.")
+
 gopts.var('acpi', val='ACPI',
           fn=set_int, default=1,
           use="Disable or enable ACPI of HVM domain.")
@@ -750,7 +754,7 @@
 def configure_hvm(config_image, vals):
     """Create the config for HVM devices.
     """
-    args = [ 'device_model', 'pae', 'vcpus', 'boot', 'fda', 'fdb', 'timer_mode',
+    args = [ 'device_model', 'pae', 'extid', 'vcpus', 'boot', 'fda', 'fdb', 'timer_mode',
              'localtime', 'serial', 'stdvga', 'isa', 'nographic', 'soundhw',
              'vnc', 'vncdisplay', 'vncunused', 'vncconsole', 'vnclisten',
              'sdl', 'display', 'xauthority', 'rtc_timeoffset', 'monitor',