qemu: Need to check for machine.os when using ADDRESS_TYPE_CCW

https://bugzilla.redhat.com/show_bug.cgi?id=1258361

When attaching a disk, controller, or rng using an address type ccw
or s390, we need to ensure the support is provided by both the machine.os
and the emulator capabilities (corollary to unconditional setting when
address was not provided for the correct machine.os and emulator.

For an inactive guest, an addition followed by a start would cause the
startup to fail after qemu_command builds the command line and attempts
to start the guest. For an active guest, libvirtd would crash.

src/qemu/qemu_command.c

@@ -3585,6 +3585,46 @@ qemuCheckDiskConfig(virDomainDiskDefPtr disk)
 }
 
 
+/* Check whether the device address is using either 'ccw' or default s390
+ * address format and whether that's "legal" for the current qemu and/or
+ * guest os.machine type. This is the corollary to the code which doesn't
+ * find the address type set using an emulator that supports either 'ccw'
+ * or s390 and sets the address type based on the capabilities.
+ *
+ * If the address is using 'ccw' or s390 and it's not supported, generate
+ * an error and return false; otherwise, return true.
+ */
+bool
+qemuCheckCCWS390AddressSupport(virDomainDefPtr def,
+                               virDomainDeviceInfo info,
+                               virQEMUCapsPtr qemuCaps,
+                               const char *devicename)
+{
+    if (info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_CCW) {
+        if (!qemuDomainMachineIsS390CCW(def)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("cannot use CCW address type for device "
+                             "'%s' using machine type '%s'"),
+                       devicename, def->os.machine);
+            return false;
+        } else if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_CCW)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("CCW address type is not supported by "
+                             "this QEMU"));
+            return false;
+        }
+    } else if (info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_S390) {
+        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_S390)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("virtio S390 address type is not supported by "
+                             "this QEMU"));
+            return false;
+        }
+    }
+    return true;
+}
+
+
 /* Qemu 1.2 and later have a binary flag -enable-fips that must be
  * used for VNC auth to obey FIPS settings; but the flag only
  * exists on Linux, and with no way to probe for it via QMP.  Our
@@ -4138,6 +4178,9 @@ qemuBuildDriveDevStr(virDomainDefPtr def,
         }
     }
 
+    if (!qemuCheckCCWS390AddressSupport(def, disk->info, qemuCaps, disk->dst))
+        goto error;
+
     if (disk->iothread && !qemuCheckIOThreads(def, qemuCaps, disk))
         goto error;
 
@@ -4592,6 +4635,10 @@ qemuBuildControllerDevStr(virDomainDefPtr domainDef,
     int model = def->model;
     const char *modelName = NULL;
 
+    if (!qemuCheckCCWS390AddressSupport(domainDef, def->info, qemuCaps,
+                                        "controller"))
+        return NULL;
+
     if (def->type == VIR_DOMAIN_CONTROLLER_TYPE_SCSI) {
         if ((qemuSetSCSIControllerModel(domainDef, qemuCaps, &model)) < 0)
             return NULL;
@@ -6884,6 +6931,10 @@ qemuBuildRNGDevStr(virDomainDefPtr def,
         goto error;
     }
 
+    if (!qemuCheckCCWS390AddressSupport(def, dev->info, qemuCaps,
+                                        dev->source.file))
+        goto error;
+
     if (dev->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_CCW)
         virBufferAsprintf(&buf, "virtio-rng-ccw,rng=obj%s,id=%s",
                           dev->info.alias, dev->info.alias);

src/qemu/qemu_command.h

@@ -318,4 +318,9 @@ int qemuCheckDiskConfig(virDomainDiskDefPtr disk);
 
 bool
 qemuCheckFips(void);
+
+bool qemuCheckCCWS390AddressSupport(virDomainDefPtr def,
+                                    virDomainDeviceInfo info,
+                                    virQEMUCapsPtr qemuCaps,
+                                    const char *devicename);
 #endif /* __QEMU_COMMAND_H__*/

src/qemu/qemu_hotplug.c

@@ -331,6 +331,10 @@ qemuDomainAttachVirtioDiskDevice(virConnectPtr conn,
             disk->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_CCW;
         else if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_VIRTIO_S390))
             disk->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_S390;
+    } else {
+        if (!qemuCheckCCWS390AddressSupport(vm->def, disk->info, priv->qemuCaps,
+                                            disk->dst))
+            goto cleanup;
     }
 
     for (i = 0; i < vm->def->ndisks; i++) {
@@ -448,6 +452,10 @@ int qemuDomainAttachControllerDevice(virQEMUDriverPtr driver,
                 controller->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_CCW;
             else if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_VIRTIO_S390))
                 controller->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_S390;
+        } else {
+            if (!qemuCheckCCWS390AddressSupport(vm->def, controller->info,
+                                                priv->qemuCaps, "controller"))
+                goto cleanup;
         }
 
         if (controller->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE ||
@@ -1663,6 +1671,10 @@ qemuDomainAttachRNGDevice(virQEMUDriverPtr driver,
         } else if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_VIRTIO_S390)) {
             rng->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_S390;
         }
+    } else {
+        if (!qemuCheckCCWS390AddressSupport(vm->def, rng->info, priv->qemuCaps,
+                                            rng->source.file))
+            return -1;
     }
 
     if (rng->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE ||