hmi: Add test case to trigger TOD topology switch.

This test triggers the TOD topology failover on all the chips to see OPAL
TI and panic path to make sure OS does not get stuck while going down.

This test needs following skiboot and kernel commit to pass:

skiboot:
  497734984 opal/hmi: set a flag to inform OS that TOD/TB has failed.
  ca349b836 opal/hmi: Don't retry TOD recovery if it is already in failed state.
  017da88b2 opal/hmi: Fix double unlock of hmi lock in failure path.

kernel:
  http://patchwork.ozlabs.org/patch/1051379/

Signed-off-by: Mahesh Salgaonkar <[email protected]>

Author: maheshsal

common/OPexpect.py

@@ -164,3 +164,15 @@ def expect(self, pattern, timeout=-1, searchwindowsize=-1, async=False):
             raise PlatformError(state, log)
 
         return r - len(op_patterns)
+
+    '''
+    Provide function that do not raise any exception. This is usefull for the
+    tests that do not consider panic or opal TI as test failure. This allows
+    such testcases to take control and look for specific pattern in system
+    crash scenario.
+    '''
+    def expect_no_fail(self, pattern, timeout=-1, searchwindowsize=-1, async=False):
+        r = super(spawn,self).expect(pattern,
+                                     timeout=timeout,
+                                     searchwindowsize=searchwindowsize)
+        return r

common/OpTestConstants.py

@@ -258,6 +258,7 @@ class OpTestConstants():
     TFMR_DEC_PARITY_ERROR = "0006080000000000"
     TFMR_PURR_PARITY_ERROR = "0004080000000000"
     TFMR_SPURR_PARITY_ERROR = "0005080000000000"
+    HMI_TOD_TOPOLOGY_FAILOVER = 7
 
     # CPU sleep states constants
     GET_CPU_SLEEP_STATE2 = "cat /sys/devices/system/cpu/cpu*/cpuidle/state2/disable"

testcases/OpTestHMIHandling.py

@@ -92,6 +92,26 @@ def clear_stop(self):
         else:
           self.assertTrue(False, "OpTestHMIHandling failed to recover from previous OpSystemState.UNKNOWN_BAD")
 
+    def handle_panic(self):
+        rc = self.cv_SYSTEM.console.pty.expect_no_fail(["Kernel panic - not syncing: Unrecoverable HMI exception", pexpect.TIMEOUT, pexpect.EOF], timeout=120)
+        if rc == 0:
+            rc = self.cv_SYSTEM.console.pty.expect_no_fail(["ISTEP", pexpect.TIMEOUT, pexpect.EOF], timeout=120)
+            if rc == 0:
+                self.cv_SYSTEM.set_state(OpSystemState.IPLing)
+                self.cv_SYSTEM.goto_state(OpSystemState.OS)
+            else:
+                self.assertTrue(False, "OpTestHMIHandling: System failing to reboot after topology recovery failure")
+        else:
+          self.assertTrue(False, "OpTestHMIHandling: No panic after topology recovery failure")
+
+    def handle_OpalTI(self):
+        rc = self.cv_SYSTEM.console.pty.expect_no_fail(["ISTEP", pexpect.TIMEOUT, pexpect.EOF], timeout=120)
+        if rc == 0:
+            self.cv_SYSTEM.set_state(OpSystemState.IPLing)
+            self.cv_SYSTEM.goto_state(OpSystemState.OS)
+        else:
+            self.assertTrue(False, "System failed to reboot after OPAL TI")
+
     def handle_ipl(self):
         rc = self.cv_SYSTEM.console.pty.expect(["ISTEP", pexpect.TIMEOUT, pexpect.EOF], timeout=120)
         if rc == 0:
@@ -202,6 +222,54 @@ def form_scom_addr(self, addr, core):
             log.debug(val)
         return val
 
+    def is_node_present(self, node):
+        ''' Check if specified device tree is present or not.'''
+        self.cv_SYSTEM.goto_state(OpSystemState.OS)
+        l_cmd = "ls %s" % node
+        try:
+            self.cv_HOST.host_run_command(l_cmd, console=1)
+        except CommandFailed as cf:
+            '''Node is not present '''
+            return 0
+
+        return 1
+
+    def get_OpalSwXstop(self):
+        self.proc_gen = self.cv_HOST.host_get_proc_gen(console=1)
+        self.cv_SYSTEM.goto_state(OpSystemState.OS)
+        try:
+            o = self.cv_HOST.host_run_command("nvram -p ibm,skiboot --print-config=opal-sw-xstop", console=1)
+            '''
+            On a fresh system this isn't set. The command will exit with
+            exitcode = 255.
+            On power8 we treat this as enabled
+            On power9 we treat this as disable.
+            '''
+        except CommandFailed as cf:
+            if cf.exitcode == 255:
+                if self.proc_gen in ["POWER8", "POWER8E"]:
+                    return "enable"
+                elif self.proc_gen in ["POWER9"]:
+                    return "disable"
+            else:
+                self.assertTrue(False, "get_OpalSwXstop() failed to query nvram.")
+        return o
+
+    def set_OpalSwXstop(self, val):
+        self.cv_SYSTEM.goto_state(OpSystemState.OS)
+        o = self.get_OpalSwXstop()
+        if val in o:
+            return
+
+        l_cmd = "nvram -p ibm,skiboot --update-config opal-sw-xstop=%s" % val
+        self.cv_HOST.host_run_command(l_cmd, console=1)
+        o = self.get_OpalSwXstop()
+        if val in o:
+            pass
+        else:
+            l_msg = "Failed to set opal-sw-xstop config to %s" % val
+            self.assertTrue(False, l_msg)
+
     def clearGardEntries(self):
         self.cv_SYSTEM.goto_state(OpSystemState.OS)
         self.util.PingFunc(self.cv_HOST.ip, BMC_CONST.PING_RETRY_POWERCYCLE)
@@ -287,6 +355,8 @@ def _testHMIHandling(self, i_test):
             self._testTFMR_Errors(BMC_CONST.TFMR_DEC_PARITY_ERROR)
             self._testTFMR_Errors(BMC_CONST.TFMR_PURR_PARITY_ERROR)
             self._testTFMR_Errors(BMC_CONST.TFMR_SPURR_PARITY_ERROR)
+        elif l_test == BMC_CONST.HMI_TOD_TOPOLOGY_FAILOVER:
+            self._test_tod_topology_failover()
         else:
             raise Exception("Please provide valid test case")
         l_con.run_command("dmesg -C")
@@ -407,6 +477,43 @@ def _test_malfunction_alert(self):
         console.pty.sendline(l_cmd)
         self.handle_ipl()
 
+    def _test_tod_topology_failover(self):
+        '''
+        This function is used to test error path for hmi TOD topology failover.
+        On HMI recovery failure TOD/TB goes in invalid state and stops running.
+        In this case kernel should either
+        a) panic followed by clean reboot. (For opal-sw-xstop=disable)
+            OR
+        b) cause OPAL TI by triggering sw checkstop to OCC. (For
+           opal-sw-xstop=enable)
+
+        In both cases we should not see any hangs at Linux OS level.
+        To simulate error condition inject TOD topology failover on all the
+        chips until we see HMI failure.
+        '''
+        scom_addr = "0x40000"
+        l_error = "0x4000000000000000"
+        l_test_mode = "TI"
+
+        g = self.get_OpalSwXstop()
+        if "disable" in g:
+            l_test_mode="panic"
+
+        console = self.cv_SYSTEM.console
+        l_cmd = ""
+        for l_pair in self.l_dic:
+            l_chip = l_pair[0]
+            l_cmd_str = "PATH=/usr/local/sbin:$PATH putscom -c %s %s %s; " % (l_chip, scom_addr, l_error)
+            l_cmd = l_cmd + l_cmd_str
+
+        console.pty.sendline(l_cmd)
+        if l_test_mode == "panic":
+            self.handle_panic()
+        else:
+            self.handle_OpalTI()
+
+        return
+
     def _test_hyp_resource_err(self):
         '''
         This function is used to test HMI: Hypervisor resource error
@@ -563,6 +670,20 @@ def runTest(self):
         self._testHMIHandling(BMC_CONST.HMI_MALFUNCTION_ALERT)
         self.clearGardEntries()
 
+class TodTopologyFailoverPanic(OpTestHMIHandling):
+    def runTest(self):
+        self.set_OpalSwXstop("disable")
+        self._testHMIHandling(BMC_CONST.HMI_TOD_TOPOLOGY_FAILOVER)
+
+class TodTopologyFailoverOpalTI(OpTestHMIHandling):
+    def runTest(self):
+        rc = self.is_node_present("/proc/device-tree/ibm,sw-checkstop-fir")
+        if rc == 1:
+            self.set_OpalSwXstop("enable")
+            self._testHMIHandling(BMC_CONST.HMI_TOD_TOPOLOGY_FAILOVER)
+        else:
+            self.skipTest("OPAL TI not supported on this system.")
+
 class HypervisorResourceError(OpTestHMIHandling):
     def runTest(self):
         self._testHMIHandling(BMC_CONST.HMI_HYPERVISOR_RESOURCE_ERROR)
@@ -576,6 +697,8 @@ def unrecoverable_suite():
     s = unittest.TestSuite()
     s.addTest(MalfunctionAlert())
     s.addTest(HypervisorResourceError())
+    s.addTest(TodTopologyFailoverPanic())
+    s.addTest(TodTopologyFailoverOpalTI())
     s.addTest(ClearGard())
     return s