diff -urN kvm_runtest_2.bak/cpu_stress.c kvm_runtest_2/cpu_stress.c
--- kvm_runtest_2.bak/cpu_stress.c	1969-12-31 19:00:00.000000000 -0500
+++ kvm_runtest_2/cpu_stress.c	2009-05-05 22:35:34.000000000 -0400
@@ -0,0 +1,61 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <pthread.h>
+#include <sched.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <math.h>
+#include <unistd.h>
+
+#define MAX_CPUS 256
+#define BUFFSIZE 1024
+
+
+void worker_child(int cpu)
+{
+	int cur_freq;
+	int min_freq;
+	int max_freq;
+	int last_freq;
+	cpu_set_t mask;
+	int i;
+	double x;
+        int d = 0;
+	/*
+	 * bind this thread to the specified cpu 
+	 */
+	CPU_ZERO(&mask);
+	CPU_SET(cpu, &mask);
+	sched_setaffinity(0, CPU_SETSIZE, &mask);
+
+	while (d++ != 500000) {
+			for (i=0; i<100000; i++)
+				x = sqrt(x);
+	}
+
+	_exit(0);
+
+}
+
+
+main() {
+	cpu_set_t mask;
+	int i;
+	int code;
+
+	if (sched_getaffinity(0, CPU_SETSIZE, &mask) < 0){
+		perror ("sched_getaffinity");
+		exit(1);
+	}
+
+	for (i=0; i<CPU_SETSIZE; i++)
+		if (CPU_ISSET(i, &mask)){
+			printf ("CPU%d\n",i);
+			if (fork() == 0)
+				worker_child(i);
+		}
+
+
+	wait(&code);
+	exit (WEXITSTATUS(code));
+}
diff -urN kvm_runtest_2.bak/kvm_runtest_2.py kvm_runtest_2/kvm_runtest_2.py
--- kvm_runtest_2.bak/kvm_runtest_2.py	2009-04-29 06:17:29.000000000 -0400
+++ kvm_runtest_2/kvm_runtest_2.py	2009-04-29 08:06:32.000000000 -0400
@@ -36,6 +36,8 @@
                 "autotest":     test_routine("kvm_tests",           "run_autotest"),
                 "kvm_install":  test_routine("kvm_install",         "run_kvm_install"),
                 "linux_s3":     test_routine("kvm_tests",           "run_linux_s3"),
+                "ntp_server_setup": test_routine("kvm_tests",       "run_ntp_server_setup"),
+                "timedrift":    test_routine("kvm_tests",           "run_timedrift"),
                 }
 
         # Make it possible to import modules from the test's bindir
diff -urN kvm_runtest_2.bak/kvm_tests.cfg.sample kvm_runtest_2/kvm_tests.cfg.sample
--- kvm_runtest_2.bak/kvm_tests.cfg.sample	2009-04-29 06:17:29.000000000 -0400
+++ kvm_runtest_2/kvm_tests.cfg.sample	2009-04-29 08:09:36.000000000 -0400
@@ -81,6 +81,10 @@
     - linux_s3:      install setup
         type = linux_s3
 
+    - ntp_server_setup:
+        type = ntp_server_setup
+    - timedrift:      ntp_server_setup
+        type = timedrift
 # NICs
 variants:
     - @rtl8139:
diff -urN kvm_runtest_2.bak/kvm_tests.py kvm_runtest_2/kvm_tests.py
--- kvm_runtest_2.bak/kvm_tests.py	2009-04-29 06:17:29.000000000 -0400
+++ kvm_runtest_2/kvm_tests.py	2009-05-11 06:00:32.000000000 -0400
@@ -394,3 +394,247 @@
     kvm_log.info("VM resumed after S3")
 
     session.close()
+
+def run_ntp_server_setup(test, params, env):
+    
+    """NTP server configuration and related network file modification
+    """
+
+    kvm_log.info("stop the iptables service if it is running for timedrift testing")
+
+    if not os.system("/etc/init.d/iptables status"):
+        os.system("/etc/init.d/iptables stop")
+
+    # prevent dhcp client modify the ntp.conf
+    kvm_log.info("prevent dhcp client modify the ntp.conf")
+
+    config_file = "/etc/sysconfig/network"
+    network_file = open("/etc/sysconfig/network", "a")
+    string = "PEERNTP=no"
+
+    if os.system("grep %s %s" % (string, config_file)):
+        network_file.writelines(str(string)+'\n')
+    
+    network_file.close()
+  
+    # stop the ntp service if it is running
+    kvm_log.info("stop ntp service if it is running")
+
+    if not os.system("/etc/init.d/ntpd status"):
+        os.system("/etc/init.d/ntpd stop")
+        ntp_running = True
+
+    kvm_log.info("start ntp server on host with the custom config file.")
+
+    ntp_cmd = '''
+        echo "restrict default kod nomodify notrap nopeer noquery" >> /etc/timedrift.ntp.conf;\
+        echo "restrict 127.0.0.1" >> /etc/timedrift.ntp.conf;\
+        echo "driftfile /var/lib/ntp/drift" >> /etc/timedrift.ntp.conf;\
+        echo "keys /etc/ntp/keys" >> /etc/timedrift.ntp.conf;\
+        echo "server 127.127.1.0" >> /etc/timedrift.ntp.conf;\
+        echo "fudge 127.127.1.0 stratum 1" >> /etc/timedrift.ntp.conf;\
+        ntpd -c /etc/timedrift.ntp.conf;
+        '''
+    if os.system(ntp_cmd):
+        raise error.TestFail, "NTP server has not starting correct..."
+
+    #kvm_log.info("sync system clock to BIOS")
+    #os.system("/sbin/hwclock --systohc")
+   
+def run_timedrift(test, params, env):
+    """judge wether the guest clock will encounter timedrift prblem or not. including three stages:
+       1: try to sync the clock with host, if the offset value of guest clock is large than 1 sec.
+       2: running the cpu stress testing program<cpu_stress.c> on guest
+       3: then run analyze loop totally 20 times to determine if the clock on guest has time drift.
+    """
+    # variables using in timedrift testcase
+    cpu_stress_program = "cpu_stress.c"
+    remote_dir = '/root'
+
+    clock_resource_cmd = "cat /sys/devices/system/clocksource/clocksource0/current_clocksource"
+
+    pwd = os.path.join(os.environ['AUTODIR'],'tests/kvm_runtest_2')
+    cpu_stress_test = os.path.join(pwd, cpu_stress_program)
+    cpu_stress_cmdline = 'cd %s;gcc %s -lm;./a.out &' % (remote_dir, os.path.basename(cpu_stress_test))
+
+    cpu_stress_search_cmdline = "ps -ef|grep 'a.out'|grep -v grep"
+
+    hostname = os.environ.get("HOSTNAME")
+    if "localhost.localdomain" == hostname:
+        hostname = os.popen('hostname').read().split('\n')[0]
+        kvm_log.info("since get wrong hostname from python evnironment, then use the hostname get from system call(hostname).")
+
+    kvm_log.info("get host name :%s" % hostname)
+
+    # ntpdate info command and ntpdate sync command
+    ntpdate_info_cmd = "ntpdate -q %s" % hostname
+    ntpdate_sync_cmd = "ntpdate %s" % hostname
+
+    # get vm handle
+    vm = kvm_utils.env_get_vm(env,params.get("main_vm"))
+    if not vm:
+        raise error.TestError, "VM object not found in environment"
+    if not vm.is_alive():
+        raise error.TestError, "VM seems to be dead; Test requires a living VM"
+
+    kvm_log.info("Waiting for guest to be up...")
+
+    pxssh = kvm_utils.wait_for(vm.ssh_login, 240, 0, 2)
+    if not pxssh:
+        raise error.TestFail, "Could not log into guest"
+
+    kvm_log.info("Logged into guest IN run_timedrift function.")
+
+    # clock resource get from host and guest
+    host_clock_resource = os.popen(clock_resource_cmd).read().split('\n')[0]
+    kvm_log.info("the clock resource on host is :%s" % host_clock_resource)
+
+    pxssh.sendline(clock_resource_cmd)
+    s, o = pxssh.read_up_to_prompt()
+    guest_clock_resource = o.splitlines()[-2]
+    kvm_log.info("the clock resource on guest is :%s" % guest_clock_resource)
+
+    if host_clock_resource != guest_clock_resource:
+        #raise error.TestFail, "Host and Guest using different clock resource"
+        kvm_log.info("Host and Guest using different clock resource,Let's moving on.")
+    else:
+        kvm_log.info("Host and Guest using same clock resource,Let's moving on.")
+
+    # helper function: 
+    # ntpdate_op: a entire process to get ntpdate command line result from guest.
+    # time_drift_or_not: get the numeric handing by regular expression and make timedrift calulation.
+    def ntpdate_op(command):
+        output = []
+        try:
+            pxssh = kvm_utils.wait_for(vm.ssh_login, 240, 0, 2)
+            if not pxssh:
+                raise error.TestFail, "Could not log into guest"
+
+            kvm_log.info("Logged in:(ntpdate_op)")
+
+            while True:
+                pxssh.sendline(command)
+                s, output = pxssh.read_up_to_prompt()
+                if "time server" in output:
+                    # output is a string contain the (ntpdate -q) infor on guest
+                    return True, output
+                else:
+                    continue
+        except:
+            pxssh.close()
+            return False, output
+        return False, output
+
+    def time_drift_or_not(output):
+        date_string = re.findall(r'offset [+-]?(.*) sec', output, re.M)
+        num = float(date_string[0])
+        if num >= 1:
+            kvm_log.info("guest clock has drifted in this scenario :%s %s" % (date_string, num))
+            return False
+        else:
+            kvm_log.info("guest clock running veracious in now stage :%s %s" % (date_string, num))
+            return True
+
+    # send the command and get the ouput from guest
+    # this loop will pick out several conditions need to be process
+    # Actually, we want to get the info match "time server", then script can analyzing it to
+    # determine if guest's clock need sync with host or not.
+    while True:
+        pxssh.sendline(ntpdate_info_cmd)
+        s, output = pxssh.read_up_to_prompt()
+        kvm_log.info("the ntpdate query info get from guest is below: \n%s" %output)
+        if ("no server suitable" not in output) and ("time server" not in output):
+            kvm_log.info("very creazying output got. let's try again")
+            continue
+        elif "no server suitable" in output:
+            kvm_log.info("seems NTP server is not ready for servicing")
+            time.sleep(30)
+            continue
+        elif "time server" in output:
+            # get the ntpdate info from guest
+            # kvm_log.info("Got the correct output for analyze. The output is below: \n%s" %output) 
+            break
+
+    kvm_log.info("get the ntpdate infomation from guest successfully :%s" % os.popen('date').read())
+
+    # judge the clock need to sync with host or not
+    while True:
+        date_string = re.findall(r'offset [+-]?(.*) sec', output, re.M)
+        num = float(date_string[0])
+        if num >= 1:
+            kvm_log.info("guest need sync with the server: %s" % hostname)
+            s, output = ntpdate_op(ntpdate_sync_cmd)
+            if s:
+                continue
+        else:
+            #pxssh.sendline("hwclock --systohc")
+            #kvm_log.info("guest clock sync prcdure is finished. then sync the guest clock to guest bios.")
+
+            #pxssh.sendline("hwclock --show")
+            #s, o = pxssh.read_up_to_prompt()
+            #kvm_log.info("the date infomation get from guest bios is :\n%s" % o)
+
+            pxssh.sendline(ntpdate_info_cmd)
+            s, o = pxssh.read_up_to_prompt()
+            kvm_log.info("guest clock after sync with host is :\n%s" % o)
+
+            break
+
+    kvm_log.info("Timedrift Preparation *Finished* at last :%s" % os.popen('date').read())
+
+    if not vm.scp_to_remote(cpu_stress_test, remote_dir):
+        raise error.TestError, "Could not copy program to guest."
+
+    pxssh.sendline(ntpdate_info_cmd)
+    s, o = pxssh.read_up_to_prompt()
+    kvm_log.info("the ntpdate query from host *BEFORE* running the cpu stress program.\n%s" % o)
+    pxssh.sendline(cpu_stress_cmdline)
+    s, o = pxssh.read_up_to_prompt()
+    kvm_log.info("running command line on guest and sleeping for 1200 secs.\n%s" % o)
+
+    time.sleep(1200)
+
+    while True:
+        if pxssh.get_command_status(cpu_stress_search_cmdline):
+            #(s, o) = pxssh.get_command_status_output(cpu_stress_search_cmdline)
+            #print "s is :%s" % s
+            #print "o is :%s" % o
+            #print "--------------------------------------------"
+            #aaa = pxssh.get_command_status(cpu_stress_search_cmdline)
+            #print "aaa is :%s" % aaa
+            #print "--------------------------------------------"
+
+            print "stress testing process has been completed and quit."
+            break
+        else:
+            print "stress testing on CPU has not finished yet.waiting for next detect after sleep 60 secs."
+            time.sleep(60)
+            continue
+
+    pxssh.sendline(ntpdate_info_cmd)
+    s, o = pxssh.read_up_to_prompt()
+    kvm_log.info("the ntpdate query from host *AFTER* running the cpu stress program.\n%s" % o)
+
+    pxssh.close()
+
+    # Sleep for analyze...
+    kvm_log.info("sleeping(180 secs) Starting... :%s" % os.popen('date').read())
+    time.sleep(180)
+    kvm_log.info("wakeup to get the analyzing... :%s" % os.popen('date').read())
+    count = 0
+    for i in range(1, 21):
+        kvm_log.info("this is %s time to get clock info from guest." % i)
+        s, o = ntpdate_op(ntpdate_info_cmd)
+        
+        if not s:
+            raise error.TestFail, "Guest seems hang or ssh service based on guest has been crash down"
+        
+        if not time_drift_or_not(o):
+            count += 1
+
+        if count == 5:
+            raise error.TestFail, "TimeDrift testing Abort because guest's clock has drift too much"
+
+        kvm_log.info("*********************** Sleep 30 seconds for next loop *************************")
+        time.sleep(60)
+