timedrift: add case to check time offset after hotplugging vcpu

Signed-off-by: NSitong Liu <siliu@redhat.com>

qemu/tests/cfg/timedrift_check_clock_offset.cfg

@@ -37,3 +37,15 @@
                     ntp_cmd = "(systemctl stop chronyd || service ntpdate stop)"
                     ntp_cmd += " && chronyd -q 'server clock.redhat.com iburst'"
                     ntp_query_cmd = "chronyd -Q 'server clock.redhat.com iburst'"
+        - hotplug_vcpu:
+            type = timedrift_check_when_hotplug_vcpu
+            start_vm = yes
+            vcpu_sockets = 2
+            smp = 4
+            vcpus_maxcpus = 6
+            ntp_query_cmd = "chronyd -Q 'server clock.redhat.com iburst'"
+            clock_sync_command = "(systemctl stop chronyd || service ntpdate stop)"
+            clock_sync_command += " && chronyd -q 'server clock.redhat.com iburst'"
+            query_internal = 600
+            query_times = 4
+            drift_threshold = 3

qemu/tests/timedrift_check_when_hotplug_vcpu.py

+import re
+import time
+import logging
+
+from avocado.utils import process
+
+from virttest import error_context
+
+
+@error_context.context_aware
+def run(test, params, env):
+    """
+    Check time offset after hotplug a vcpu.
+
+    1) sync host time with ntpserver
+    2) boot guest with '-rtc base=utc,clock=host,driftfix=slew'
+    3) stop auto sync service in guest (rhel7 only)
+    4) sync guest system time with ntpserver
+    5) hotplug a vcpu by qmp command
+    6) query guest time offset with ntpserver for several times
+
+    :param test: QEMU test object.
+    :param params: Dictionary with test parameters.
+    :param env: Dictionary with the test environment.
+    """
+    clock_sync_command = params["clock_sync_command"]
+
+    error_context.context("Sync host system time with ntpserver", logging.info)
+    process.system(clock_sync_command, shell=True)
+
+    vm = env.get_vm(params["main_vm"])
+    session = vm.wait_for_login()
+
+    ntp_query_cmd = params.get("ntp_query_cmd", "")
+    query_times = int(params.get("query_times", "4"))
+    query_internal = float(params.get("query_internal", "600"))
+    drift_threshold = float(params.get("drift_threshold", "3"))
+
+    error_context.context("Sync time from guest to ntpserver", logging.info)
+    session.cmd(clock_sync_command)
+
+    error_context.context("Hotplug a vcpu to guest", logging.info)
+    if int(params["smp"]) < int(params["vcpus_maxcpus"]):
+        vm.hotplug_vcpu()
+        time.sleep(1)
+    else:
+        test.error("Invalid operation, valid index range 0:%d, used range 0:%d"
+                   % (int(params["vcpus_maxcpus"])-1, int(params["smp"]) - 1))
+
+    error_context.context("Check time offset via ntp server", logging.info)
+    for query in range(query_times):
+        output = session.cmd_output(ntp_query_cmd)
+        try:
+            offset = re.findall(r"([+-]*\d+\.\d+) seconds", output, re.M)[0]
+        except IndexError:
+            test.error("Failed to get time offset")
+        if float(offset) >= drift_threshold:
+            test.fail("Uacceptable offset '%s', " % offset +
+                      "threshold '%s'" % drift_threshold)
+        time.sleep(query_internal)
+    session.close()