Index: xen/xen-unstable.hg/linux-2.6-xen-sparse/drivers/char/tpm/tpm.c
===================================================================
--- xen.orig/xen-unstable.hg/linux-2.6-xen-sparse/drivers/char/tpm/tpm.c
+++ xen/xen-unstable.hg/linux-2.6-xen-sparse/drivers/char/tpm/tpm.c
@@ -53,7 +53,7 @@ static void timeout_work(void * ptr)
 
 	down(&chip->buffer_mutex);
 	atomic_set(&chip->data_pending, 0);
-	memset(chip->data_buffer, 0, chip->vendor->buffersize);
+	memset(chip->data_buffer, 0, get_chip_buffersize(chip));
 	up(&chip->buffer_mutex);
 }
 
@@ -352,7 +352,7 @@ int tpm_open(struct inode *inode, struct
 
 	spin_unlock(&driver_lock);
 
-	chip->data_buffer = kmalloc(chip->vendor->buffersize * sizeof(u8), GFP_KERNEL);
+	chip->data_buffer = kmalloc(get_chip_buffersize(chip) * sizeof(u8), GFP_KERNEL);
 	if (chip->data_buffer == NULL) {
 		chip->num_opens--;
 		put_device(chip->dev);
@@ -400,8 +400,8 @@ ssize_t tpm_write(struct file *file, con
 
 	down(&chip->buffer_mutex);
 
-	if (in_size > chip->vendor->buffersize)
-		in_size = chip->vendor->buffersize;
+	if (in_size > get_chip_buffersize(chip))
+		in_size = get_chip_buffersize(chip);
 
 	if (copy_from_user
 	    (chip->data_buffer, (void __user *) buf, in_size)) {
@@ -411,7 +411,7 @@ ssize_t tpm_write(struct file *file, con
 
 	/* atomic tpm command send and result receive */
 	out_size = tpm_transmit(chip, chip->data_buffer, 
-	                        chip->vendor->buffersize);
+	                        get_chip_buffersize(chip));
 
 	atomic_set(&chip->data_pending, out_size);
 	atomic_set(&chip->data_position, 0);
@@ -432,8 +432,6 @@ ssize_t tpm_read(struct file * file, cha
 	int ret_size;
 	int pos, pending = 0;
 
-	del_singleshot_timer_sync(&chip->user_read_timer);
-	flush_scheduled_work();
 	ret_size = atomic_read(&chip->data_pending);
 	if (ret_size > 0) {	/* relay data */
 		if (size < ret_size)
@@ -457,6 +455,7 @@ ssize_t tpm_read(struct file * file, cha
 	if ( ret_size <= 0 || pending == 0 ) {
 		atomic_set( &chip->data_pending, 0 );
 		del_singleshot_timer_sync(&chip->user_read_timer);
+		flush_scheduled_work();
 	}
 
 	return ret_size;
Index: xen/xen-unstable.hg/linux-2.6-xen-sparse/drivers/char/tpm/tpm.h
===================================================================
--- xen.orig/xen-unstable.hg/linux-2.6-xen-sparse/drivers/char/tpm/tpm.h
+++ xen/xen-unstable.hg/linux-2.6-xen-sparse/drivers/char/tpm/tpm.h
@@ -101,6 +101,11 @@ static inline void tpm_write_index(int b
 	outb(value & 0xFF, base+1);
 }
 
+static inline u32 get_chip_buffersize(struct tpm_chip *chip)
+{
+	return chip->vendor->buffersize;
+}
+
 extern int tpm_register_hardware(struct device *,
 				 struct tpm_vendor_specific *);
 extern int tpm_open(struct inode *, struct file *);
Index: xen/xen-unstable.hg/tools/examples/vtpm-common.sh
===================================================================
--- xen.orig/xen-unstable.hg/tools/examples/vtpm-common.sh
+++ xen/xen-unstable.hg/tools/examples/vtpm-common.sh
@@ -173,6 +173,7 @@ function validate_entry () {
 	local vmname=$1
 	local inst=$2
 	local res
+
 	res=`cat $VTPMDB |             \
 	     gawk -vvmname=$vmname     \
 	          -vinst=$inst         \
@@ -238,6 +239,9 @@ function vtpm_create_instance () {
 	local res
 	set +e
 	get_create_reason
+
+	claim_lock vtpmdb
+
 	find_instance $domname
 	res=$?
 	if [ $res -eq 0 ]; then
@@ -262,6 +266,9 @@ function vtpm_create_instance () {
 			vtpm_create $instance
 		fi
 	fi
+
+	release_lock vtpmdb
+
 	if [ "$REASON" == "create" ]; then
 		vtpm_reset $instance
 	elif [ "$REASON" == "resume" ]; then
@@ -292,3 +299,5 @@ function vtpm_remove_instance () {
 	fi
 	set -e
 }
+
+
Index: xen/xen-unstable.hg/linux-2.6-xen-sparse/drivers/char/tpm/tpm_xen.c
===================================================================
--- xen.orig/xen-unstable.hg/linux-2.6-xen-sparse/drivers/char/tpm/tpm_xen.c
+++ xen/xen-unstable.hg/linux-2.6-xen-sparse/drivers/char/tpm/tpm_xen.c
@@ -25,6 +25,7 @@
 #include <xen/tpmfe.h>
 #include <linux/device.h>
 #include <linux/interrupt.h>
+#include <linux/platform_device.h>
 #include "tpm.h"
 
 /* read status bits */
@@ -455,9 +456,7 @@ static struct tpm_vendor_specific tpm_xe
 	.buffersize = 64 * 1024,
 };
 
-static struct device tpm_device = {
-	.bus_id = "vtpm",
-};
+static struct platform_device *pdev;
 
 static struct tpmfe_device tpmfe = {
 	.receive = tpm_recv,
@@ -477,23 +476,22 @@ static int __init init_xen(void)
 	 * driver
 	 */
 	if ((rc = tpm_fe_register_receiver(&tpmfe)) < 0) {
-		return rc;
+		goto err_exit;
 	}
 
 	/*
 	 * Register our device with the system.
 	 */
-	if ((rc = device_register(&tpm_device)) < 0) {
-		tpm_fe_unregister_receiver();
-		return rc;
+	pdev = platform_device_register_simple("tpm_vtpm", -1, NULL, 0);
+	if (IS_ERR(pdev)) {
+		rc = PTR_ERR(pdev);
+		goto err_unreg_fe;
 	}
 
 	tpm_xen.buffersize = tpmfe.max_tx_size;
 
-	if ((rc = tpm_register_hardware(&tpm_device, &tpm_xen)) < 0) {
-		device_unregister(&tpm_device);
-		tpm_fe_unregister_receiver();
-		return rc;
+	if ((rc = tpm_register_hardware(&pdev->dev, &tpm_xen)) < 0) {
+		goto err_unreg_pdev;
 	}
 
 	dataex.current_request = NULL;
@@ -508,13 +506,25 @@ static int __init init_xen(void)
 	disconnect_time = jiffies;
 
 	return 0;
+
+
+err_unreg_pdev:
+	platform_device_unregister(pdev);
+err_unreg_fe:
+	tpm_fe_unregister_receiver();
+
+err_exit:
+	return rc;
 }
 
 static void __exit cleanup_xen(void)
 {
-	tpm_remove_hardware(&tpm_device);
-	device_unregister(&tpm_device);
-	tpm_fe_unregister_receiver();
+	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
+	if (chip) {
+		tpm_remove_hardware(chip->dev);
+		platform_device_unregister(pdev);
+		tpm_fe_unregister_receiver();
+	}
 }
 
 module_init(init_xen);
Index: xen/xen-unstable.hg/linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c
===================================================================
--- xen.orig/xen-unstable.hg/linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c
+++ xen/xen-unstable.hg/linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c
@@ -66,8 +66,6 @@ static int  packet_read_shmem(struct pac
                               u32 left);
 
 
-#define MAX_PENDING_REQS TPMIF_TX_RING_SIZE
-
 #define MIN(x,y)  (x) < (y) ? (x) : (y)
 
 
@@ -973,8 +971,6 @@ static void processing_timeout(unsigned 
 static void tpm_tx_action(unsigned long unused);
 static DECLARE_TASKLET(tpm_tx_tasklet, tpm_tx_action, 0);
 
-#define MAX_PENDING_REQS TPMIF_TX_RING_SIZE
-
 static struct list_head tpm_schedule_list;
 static spinlock_t tpm_schedule_list_lock;
 
Index: xen/xen-unstable.hg/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c
===================================================================
--- xen.orig/xen-unstable.hg/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c
+++ xen/xen-unstable.hg/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c
@@ -14,9 +14,6 @@
 #include "common.h"
 #include <xen/balloon.h>
 
-#define TPMIF_HASHSZ (2 << 5)
-#define TPMIF_HASH(_d,_h) (((int)(_d)^(int)(_h))&(TPMIF_HASHSZ-1))
-
 static kmem_cache_t *tpmif_cachep;
 int num_frontends = 0;
 
Index: xen/xen-unstable.hg/tools/examples/vtpm
===================================================================
--- xen.orig/xen-unstable.hg/tools/examples/vtpm
+++ xen/xen-unstable.hg/tools/examples/vtpm
@@ -3,6 +3,7 @@
 dir=$(dirname "$0")
 . "$dir/vtpm-common.sh"
 
+vtpm_fatal_error=0
 
 case "$command" in
   add)
@@ -19,5 +20,8 @@ case "$command" in
   ;;
 esac
 
-log debug "Successful vTPM operation '$command'."
-success
+if [ $vtpm_fatal_error -eq 0 ]; then
+	log debug "Successful vTPM operation '$command'."
+	success
+fi
+