diff -Naur xen-unstable-trp-sdp-pristine/tools/hotplug/Linux/vtpm xen-unstable-trp-sdp/tools/hotplug/Linux/vtpm
--- xen-unstable-trp-sdp-pristine/tools/hotplug/Linux/vtpm	2011-02-23 14:47:26.000000000 -0500
+++ xen-unstable-trp-sdp/tools/hotplug/Linux/vtpm	2011-02-23 14:42:11.000000000 -0500
@@ -1,22 +1,18 @@
 #!/bin/bash
 
+export PATH=$PATH:/usr/sbin:/sbin
+
 dir=$(dirname "$0")
 . "$dir/vtpm-hotplug-common.sh"
 
-vtpm_fatal_error=0
-
 case "$command" in
   add)
     vtpm_create_instance
+    success
   ;;
   remove)
     vtpm_remove_instance
+    success
   ;;
 esac
 
-if [ $vtpm_fatal_error -eq 0 ]; then
-	log debug "Successful vTPM operation '$command'."
-	success
-else
-	fatal "Error while executing vTPM operation '$command'."
-fi
diff -Naur xen-unstable-trp-sdp-pristine/tools/hotplug/Linux/vtpm-common.sh xen-unstable-trp-sdp/tools/hotplug/Linux/vtpm-common.sh
--- xen-unstable-trp-sdp-pristine/tools/hotplug/Linux/vtpm-common.sh	2011-02-23 14:47:26.000000000 -0500
+++ xen-unstable-trp-sdp/tools/hotplug/Linux/vtpm-common.sh	2011-02-23 14:42:11.000000000 -0500
@@ -98,7 +98,7 @@
 		avail=0
 	else
 		instances=$(cat $VTPMDB |                \
-		           awk                          \
+		           gawk                          \
 		           '{                            \
 		               if (1 != index($1,"#")) { \
 		                 printf("%s ",$2);       \
@@ -120,7 +120,7 @@
 function vtpmdb_get_free_instancenum () {
 	local ctr instances don found
 	instances=$(cat $VTPMDB |                \
-	           awk                          \
+	           gawk                          \
 	           '{                            \
 	               if (1 != index($1,"#")) { \
 	                 printf("%s ",$2);       \
@@ -174,7 +174,7 @@
 	inst=$2
 
 	res=$(cat $VTPMDB |            \
-	     awk -vvmname=$vmname     \
+	     gawk -vvmname=$vmname     \
 	          -vinst=$inst         \
 	     '{                        \
 	         if ( 1 == index($1,"#")) {\
@@ -209,7 +209,7 @@
 	VTPMDB_TMP="$VTPMDB".tmp
 
 	$(cat $VTPMDB |            \
-	 awk -vvmname=$vmname     \
+	 gawk -vvmname=$vmname     \
 	 '{                        \
 	    if ( $1 != vmname ) {  \
 	      print $0;            \
@@ -276,12 +276,10 @@
 
 		vtpm_create $instance
 
-		if [ $vtpm_fatal_error -eq 0 ]; then
-			if [ "$uuid" != "" ]; then
-				vtpmdb_add_instance $uuid $instance
-			else
-				vtpmdb_add_instance $domname $instance
-			fi
+		if [ "$uuid" != "" ]; then
+			vtpmdb_add_instance $uuid $instance
+		else
+			vtpmdb_add_instance $domname $instance
 		fi
 	else
 		if [ "$reason" == "resume" ]; then
@@ -290,7 +288,6 @@
 			vtpm_start $instance
 		fi
 	fi
-
 	release_lock vtpmdb
 
 	xenstore_write $XENBUS_PATH/instance $instance
@@ -322,8 +319,8 @@
 	if [ "$instance" != "0" ]; then
 		vtpm_suspend $instance
 	fi
-
 	release_lock vtpmdb
+
 }
 
 
@@ -350,13 +347,13 @@
 function vtpm_isLocalAddress() {
 	local addr res
 	addr=$(ping $1 -c 1 |  \
-	       awk '{ print substr($3,2,length($3)-2); exit }')
+	       gawk '{ print substr($3,2,length($3)-2); exit }')
 	if [ "$addr" == "" ]; then
 		echo "-1"
 		return
 	fi
 	res=$(ifconfig | grep "inet addr" |  \
-	     awk -vaddr=$addr               \
+	     gawk -vaddr=$addr               \
 	     '{                              \
 	        if ( addr == substr($2, 6)) {\
 	          print "1";                 \
diff -Naur xen-unstable-trp-sdp-pristine/tools/hotplug/Linux/vtpm-delete xen-unstable-trp-sdp/tools/hotplug/Linux/vtpm-delete
--- xen-unstable-trp-sdp-pristine/tools/hotplug/Linux/vtpm-delete	2011-02-23 14:47:26.000000000 -0500
+++ xen-unstable-trp-sdp/tools/hotplug/Linux/vtpm-delete	2011-02-23 14:42:11.000000000 -0500
@@ -5,6 +5,8 @@
 # or
 # vtpm-delete --vmname <vm name>
 
+export PATH=$PATH:/usr/sbin:/sbin
+
 dir=$(dirname "$0")
 . "$dir/vtpm-common.sh"
 
diff -Naur xen-unstable-trp-sdp-pristine/tools/hotplug/Linux/vtpm-impl xen-unstable-trp-sdp/tools/hotplug/Linux/vtpm-impl
--- xen-unstable-trp-sdp-pristine/tools/hotplug/Linux/vtpm-impl	2011-02-23 14:47:26.000000000 -0500
+++ xen-unstable-trp-sdp/tools/hotplug/Linux/vtpm-impl	2011-02-23 14:42:11.000000000 -0500
@@ -32,14 +32,16 @@
 # OF THE POSSIBILITY OF SUCH DAMAGE.
 # ===================================================================
 
-#            |        SRC        |    TAG  |      CMD SIZE     |        ORD       |mtype|strt
-TPM_CMD_OPEN=\\x00\\x00\\x00\\x00\\x01\\xc1\\x00\\x00\\x00\\x11\\x01\\x00\\x00\\x01\\x01\\x01
-TPM_CMD_RESM=\\x00\\x00\\x00\\x00\\x01\\xc1\\x00\\x00\\x00\\x11\\x01\\x00\\x00\\x01\\x01\\x02
-TPM_CMD_CLOS=\\x00\\x00\\x00\\x00\\x01\\xc1\\x00\\x00\\x00\\x0e\\x01\\x00\\x00\\x02
-TPM_CMD_DELE=\\x00\\x00\\x00\\x00\\x01\\xc1\\x00\\x00\\x00\\x0e\\x01\\x00\\x00\\x03
+export PATH=$PATH:/usr/sbin:/sbin
 
-TPM_TYPE_PVM=\\x01
-TPM_TYPE_HVM=\\x02
+#             | SRC  |TAG| CMD SZ|| ORD  |mtype|strt
+TPM_CMD_OPEN="0000000001C100000011010000010101"
+TPM_CMD_RESM="0000000001C100000011010000010102"
+TPM_CMD_CLOS="0000000001C10000000E01000002"
+TPM_CMD_DELE="0000000001C10000000E01000003"
+
+TPM_TYPE_PVM=01
+TPM_TYPE_HVM=02
 
 TPM_SUCCESS=00000000
 
@@ -70,24 +72,19 @@
  local inst=$2;
  local inst_bin=$(hex32_to_bin $inst);
 
- claim_lock vtpm_mgr
-
- #send cmd to vtpm_manager
- printf "$cmd$inst_bin" > $TX_VTPM_MANAGER
-
- #recv response
- set +e
- local resp_hex=`dd skip=10 bs=1 count=4 if=$RX_VTPM_MANAGER 2> /dev/null | xxd -ps`
- set -e
+ local resp_hex
+ #send cmd to vtpm_manager and get response
+ if ! resp_hex=`echo "$cmd$(str_to_hex32 $inst)" | vtpmmgrtalk `; then
+   release_lock vtpmdb
+   fatal "Error communicating with vTPM Manager"
+ fi
 
- release_lock vtpm_mgr
+ resp_hex=`echo $resp_hex | cut -b 21-`
 
  #return whether the command was successful
- if [ $resp_hex -ne $TPM_SUCCESS ]; then
-   vtpm_fatal_error=1
-   false
-  else
-   true
+ if [ "$resp_hex" != "$TPM_SUCCESS" ]; then
+   release_lock vtpmdb
+   fatal "vTPM Manager returned failure code $resp_hex"
  fi
 }
 
@@ -142,13 +139,8 @@
 
 function vtpm_delete() {
  local inst=$1
- if $(vtpm_manager_cmd $TPM_CMD_DELE $inst); then
-   rm -f /var/vtpm/vtpm_dm_$1.data
-   true
- else 
-   vtpm_fatal_error=1
-   false
- fi
+ $(vtpm_manager_cmd $TPM_CMD_DELE $inst)
+ rm -f /var/vtpm/vtpm_dm_$1.data
 }
 
 # Perform a migration step. This function differentiates between migration
diff -Naur xen-unstable-trp-sdp-pristine/tools/python/xen/xend/server/tpmif.py xen-unstable-trp-sdp/tools/python/xen/xend/server/tpmif.py
--- xen-unstable-trp-sdp-pristine/tools/python/xen/xend/server/tpmif.py	2011-02-23 14:47:26.000000000 -0500
+++ xen-unstable-trp-sdp/tools/python/xen/xend/server/tpmif.py	2011-02-23 19:40:48.000000000 -0500
@@ -44,6 +44,22 @@
         DevController.__init__(self, vm)
 
 
+    def createDevice(self, config):
+        #Disable hotplug scripts if backend is not dom0
+        import xen.xend.XendDomain
+        xd = xen.xend.XendDomain.instance()
+        backdom_name = config.get('backend')
+        if backdom_name is None:
+            backdom = xen.xend.XendDomain.DOM0_ID
+        else:
+            bd = xd.domain_lookup_nr(backdom_name)
+            backdom = bd.getDomid()
+
+	if backdom != xen.xend.XendDomain.DOM0_ID:
+	   self.hotplug = False
+
+        return DevController.createDevice(self, config)
+
     def getDeviceDetails(self, config):
         """@see DevController.getDeviceDetails"""