Adds power diag support to vbmc

Also enhance vbmc to support power diag, i.e.
- Pulse a diagnostic interrupt (NMI) directly to
  the processor(s)

Change-Id: I7b1998d36fbcbbab3870085dd5a476f77853b3e4

virtualbmc/tests/unit/test_vbmc.py

@@ -128,6 +128,30 @@ class VirtualBMCTestCase(base.TestCase):
         self._assert_libvirt_calls(mock_libvirt_domain, mock_libvirt_open,
                                    readonly=True)
 
+    def test_pulse_diag_is_on(self, mock_libvirt_domain, mock_libvirt_open):
+        domain = mock_libvirt_domain.return_value
+        domain.isActive.return_value = True
+        self.vbmc.pulse_diag()
+
+        domain.injectNMI.assert_called_once_with()
+        self._assert_libvirt_calls(mock_libvirt_domain, mock_libvirt_open)
+
+    def test_pulse_diag_is_off(self, mock_libvirt_domain, mock_libvirt_open):
+        domain = mock_libvirt_domain.return_value
+        domain.isActive.return_value = False
+        self.vbmc.pulse_diag()
+
+        # power is already off, assert injectNMI() wasn't invoked
+        domain.injectNMI.assert_not_called()
+        self._assert_libvirt_calls(mock_libvirt_domain, mock_libvirt_open)
+
+    def test_pulse_diag_error(self, mock_libvirt_domain, mock_libvirt_open):
+        mock_libvirt_domain.side_effect = libvirt.libvirtError('boom')
+        ret = self.vbmc.pulse_diag()
+        self.assertEqual(0xd5, ret)
+        mock_libvirt_domain.return_value.injectNMI.assert_not_called()
+        self._assert_libvirt_calls(mock_libvirt_domain, mock_libvirt_open)
+
     def test_power_off_is_on(self, mock_libvirt_domain, mock_libvirt_open):
         domain = mock_libvirt_domain.return_value
         domain.isActive.return_value = True

virtualbmc/vbmc.py

@@ -107,6 +107,20 @@ class VirtualBMC(bmc.Bmc):
 
         return POWEROFF
 
+    def pulse_diag(self):
+        LOG.debug('Power diag called for domain %s', self.domain_name)
+        try:
+            with utils.libvirt_open(**self._conn_args) as conn:
+                domain = utils.get_libvirt_domain(conn, self.domain_name)
+                if domain.isActive():
+                    domain.injectNMI()
+        except libvirt.libvirtError as e:
+            LOG.error('Error powering diag the domain %(domain)s. '
+                      'Error: %(error)s' % {'domain': self.domain_name,
+                                            'error': e})
+            # Command not supported in present state
+            return 0xd5
+
     def power_off(self):
         LOG.debug('Power off called for domain %s', self.domain_name)
         try: