conf: Make switch statements more strict

When switching over the values in the virDomainControllerModelPCI
enumeration, make sure the proper cast is in place so that the
compiler can warn us when the coverage is not exaustive.

For the same reason, remove the 'default' case from one of the
existing switch statements.

src/conf/domain_addr.c

@@ -344,9 +344,9 @@ virDomainPCIAddressBusSetModel(virDomainPCIAddressBusPtr bus,
         bus->maxSlot = VIR_PCI_ADDRESS_SLOT_LAST;
         break;
 
-    default:
+    case VIR_DOMAIN_CONTROLLER_MODEL_PCI_LAST:
         virReportError(VIR_ERR_INTERNAL_ERROR,
-                       _("Invalid PCI controller model %d"), model);
+                       "%s", _("PCI controller model was not set correctly"));
         return -1;
     }
 

src/conf/domain_conf.c

@@ -8834,7 +8834,7 @@ virDomainControllerDefParseXML(xmlNodePtr node,
         break;
     }
     case VIR_DOMAIN_CONTROLLER_TYPE_PCI:
-        switch (def->model) {
+        switch ((virDomainControllerModelPCI) def->model) {
         case VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT:
         case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT: {
             unsigned long long bytes;
@@ -8859,6 +8859,16 @@ virDomainControllerDefParseXML(xmlNodePtr node,
                 def->opts.pciopts.pcihole64 = true;
             def->opts.pciopts.pcihole64size = VIR_DIV_UP(bytes, 1024);
         }
+        case VIR_DOMAIN_CONTROLLER_MODEL_PCI_BRIDGE:
+        case VIR_DOMAIN_CONTROLLER_MODEL_DMI_TO_PCI_BRIDGE:
+        case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT_PORT:
+        case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_SWITCH_UPSTREAM_PORT:
+        case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_SWITCH_DOWNSTREAM_PORT:
+        case VIR_DOMAIN_CONTROLLER_MODEL_PCI_EXPANDER_BUS:
+        case VIR_DOMAIN_CONTROLLER_MODEL_PCIE_EXPANDER_BUS:
+        case VIR_DOMAIN_CONTROLLER_MODEL_PCI_LAST:
+            /* Other controller models don't require extra checks */
+            break;
         }
         if (modelName &&
             (def->opts.pciopts.modelName