diff --git a/docs/schemas/domain.rng b/docs/schemas/domain.rng
index 1d56f5b008..2ca0ad2b02 100644
--- a/docs/schemas/domain.rng
+++ b/docs/schemas/domain.rng
@@ -1310,6 +1310,19 @@
       </optional>
     </element>
   </define>
+  <define name="memballoon">
+    <element name="memballoon">
+      <attribute name="model">
+        <choice>
+          <value>virtio</value>
+          <value>xen</value>
+        </choice>
+      </attribute>
+      <optional>
+        <ref name="address"/>
+      </optional>
+    </element>
+  </define>
   <define name="parallel">
     <element name="parallel">
       <ref name="qemucdev"/>
@@ -1516,6 +1529,9 @@
         <optional>
           <ref name="watchdog"/>
         </optional>
+        <optional>
+          <ref name="memballoon"/>
+        </optional>
       </interleave>
     </element>
   </define>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index f3b8cfa3a5..0feb0cd6bc 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -189,6 +189,10 @@ VIR_ENUM_IMPL(virDomainSoundModel, VIR_DOMAIN_SOUND_MODEL_LAST,
               "pcspk",
               "ac97")
 
+VIR_ENUM_IMPL(virDomainMemballoonModel, VIR_DOMAIN_MEMBALLOON_MODEL_LAST,
+              "virtio",
+              "xen");
+
 VIR_ENUM_IMPL(virDomainWatchdogModel, VIR_DOMAIN_WATCHDOG_MODEL_LAST,
               "i6300esb",
               "ib700")
@@ -567,6 +571,16 @@ void virDomainSoundDefFree(virDomainSoundDefPtr def)
     VIR_FREE(def);
 }
 
+void virDomainMemballoonDefFree(virDomainMemballoonDefPtr def)
+{
+    if (!def)
+        return;
+
+    virDomainDeviceInfoClear(&def->info);
+
+    VIR_FREE(def);
+}
+
 void virDomainWatchdogDefFree(virDomainWatchdogDefPtr def)
 {
     if (!def)
@@ -1001,6 +1015,9 @@ int virDomainDeviceInfoIterate(virDomainDefPtr def,
     if (def->watchdog)
         if (cb(def, &def->watchdog->info, opaque) < 0)
             return -1;
+    if (def->memballoon)
+        if (cb(def, &def->memballoon->info, opaque) < 0)
+            return -1;
     if (def->console)
         if (cb(def, &def->console->info, opaque) < 0)
             return -1;
@@ -3170,6 +3187,40 @@ error:
 }
 
 
+static virDomainMemballoonDefPtr
+virDomainMemballoonDefParseXML(const xmlNodePtr node,
+                               int flags)
+{
+    char *model;
+    virDomainMemballoonDefPtr def;
+
+    if (VIR_ALLOC(def) < 0) {
+        virReportOOMError();
+        return NULL;
+    }
+
+    model = virXMLPropString(node, "model");
+    if ((def->model = virDomainMemballoonModelTypeFromString(model)) < 0) {
+        virDomainReportError(VIR_ERR_INTERNAL_ERROR,
+                             _("unknown memory balloon model '%s'"), model);
+        goto error;
+    }
+
+    if (virDomainDeviceInfoParseXML(node, &def->info, flags) < 0)
+        goto error;
+
+cleanup:
+    VIR_FREE(model);
+
+    return def;
+
+error:
+    virDomainMemballoonDefFree(def);
+    def = NULL;
+    goto cleanup;
+}
+
+
 int
 virDomainVideoDefaultRAM(virDomainDefPtr def,
                          int type)
@@ -4634,6 +4685,41 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
         VIR_FREE(nodes);
     }
 
+    /* analysis of the memballoon devices */
+    def->memballoon = NULL;
+    if ((n = virXPathNodeSet("./devices/memballoon", ctxt, &nodes)) < 0) {
+        virDomainReportError(VIR_ERR_INTERNAL_ERROR,
+                             "%s", _("cannot extract memory balloon devices"));
+        goto error;
+    }
+    if (n > 1) {
+        virDomainReportError (VIR_ERR_INTERNAL_ERROR,
+                              "%s", _("only a single memory balloon device is supported"));
+        goto error;
+    }
+    if (n > 0) {
+        virDomainMemballoonDefPtr memballoon =
+            virDomainMemballoonDefParseXML(nodes[0], flags);
+        if (!memballoon)
+            goto error;
+
+        def->memballoon = memballoon;
+        VIR_FREE(nodes);
+    } else {
+        if (def->virtType == VIR_DOMAIN_VIRT_XEN ||
+            def->virtType == VIR_DOMAIN_VIRT_QEMU ||
+            def->virtType == VIR_DOMAIN_VIRT_KQEMU ||
+            def->virtType == VIR_DOMAIN_VIRT_KVM) {
+            virDomainMemballoonDefPtr memballoon;
+            if (VIR_ALLOC(memballoon) < 0)
+                goto no_memory;
+            memballoon->model = def->virtType == VIR_DOMAIN_VIRT_XEN ?
+                VIR_DOMAIN_MEMBALLOON_MODEL_XEN :
+                VIR_DOMAIN_MEMBALLOON_MODEL_VIRTIO;
+            def->memballoon = memballoon;
+        }
+    }
+
     /* analysis of security label */
     if (virSecurityLabelDefParseXML(def, ctxt, flags) == -1)
         goto error;
@@ -5671,6 +5757,35 @@ virDomainSoundDefFormat(virBufferPtr buf,
 }
 
 
+static int
+virDomainMemballoonDefFormat(virBufferPtr buf,
+                             virDomainMemballoonDefPtr def,
+                             int flags)
+{
+    const char *model = virDomainMemballoonModelTypeToString(def->model);
+
+    if (!model) {
+        virDomainReportError(VIR_ERR_INTERNAL_ERROR,
+                             _("unexpected memballoon model %d"), def->model);
+        return -1;
+    }
+
+    virBufferVSprintf(buf, "    <memballoon model='%s'",
+                      model);
+
+    if (virDomainDeviceInfoIsSet(&def->info)) {
+        virBufferAddLit(buf, ">\n");
+        if (virDomainDeviceInfoFormat(buf, &def->info, flags) < 0)
+            return -1;
+        virBufferAddLit(buf, "    </memballoon>\n");
+    } else {
+        virBufferAddLit(buf, "/>\n");
+    }
+
+    return 0;
+}
+
+
 static int
 virDomainWatchdogDefFormat(virBufferPtr buf,
                            virDomainWatchdogDefPtr def,
@@ -6280,6 +6395,9 @@ char *virDomainDefFormat(virDomainDefPtr def,
     if (def->watchdog)
         virDomainWatchdogDefFormat (&buf, def->watchdog, flags);
 
+    if (def->memballoon)
+        virDomainMemballoonDefFormat (&buf, def->memballoon, flags);
+
     virBufferAddLit(&buf, "  </devices>\n");
 
     if (def->seclabel.model) {
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index d46869e44f..5e08aa196b 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -560,6 +560,22 @@ struct _virDomainHostdevDef {
     virDomainDeviceInfo info; /* Guest address */
 };
 
+
+enum {
+    VIR_DOMAIN_MEMBALLOON_MODEL_VIRTIO,
+    VIR_DOMAIN_MEMBALLOON_MODEL_XEN,
+
+    VIR_DOMAIN_MEMBALLOON_MODEL_LAST
+};
+
+typedef struct _virDomainMemballoonDef virDomainMemballoonDef;
+typedef virDomainMemballoonDef *virDomainMemballoonDefPtr;
+struct _virDomainMemballoonDef {
+    int model;
+    virDomainDeviceInfo info;
+};
+
+
 /* Flags for the 'type' field in next struct */
 enum virDomainDeviceType {
     VIR_DOMAIN_DEVICE_DISK,
@@ -871,6 +887,7 @@ struct _virDomainDef {
     virDomainChrDefPtr console;
     virSecurityLabelDef seclabel;
     virDomainWatchdogDefPtr watchdog;
+    virDomainMemballoonDefPtr memballoon;
     virCPUDefPtr cpu;
 };
 
@@ -931,6 +948,7 @@ void virDomainFSDefFree(virDomainFSDefPtr def);
 void virDomainNetDefFree(virDomainNetDefPtr def);
 void virDomainChrDefFree(virDomainChrDefPtr def);
 void virDomainSoundDefFree(virDomainSoundDefPtr def);
+void virDomainMemballoonDefFree(virDomainMemballoonDefPtr def);
 void virDomainWatchdogDefFree(virDomainWatchdogDefPtr def);
 void virDomainVideoDefFree(virDomainVideoDefPtr def);
 void virDomainHostdevDefFree(virDomainHostdevDefPtr def);
@@ -1109,6 +1127,7 @@ VIR_ENUM_DECL(virDomainNet)
 VIR_ENUM_DECL(virDomainChrTarget)
 VIR_ENUM_DECL(virDomainChr)
 VIR_ENUM_DECL(virDomainSoundModel)
+VIR_ENUM_DECL(virDomainMemballoonModel)
 VIR_ENUM_DECL(virDomainWatchdogModel)
 VIR_ENUM_DECL(virDomainWatchdogAction)
 VIR_ENUM_DECL(virDomainVideo)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index b5f36953bb..3573da17a9 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -170,6 +170,8 @@ virDomainSaveStatus;
 virDomainSoundDefFree;
 virDomainSoundModelTypeFromString;
 virDomainSoundModelTypeToString;
+virDomainMemballoonModelTypeFromString;
+virDomainMemballoonModelTypeToString;
 virDomainWatchdogModelTypeFromString;
 virDomainWatchdogModelTypeToString;
 virDomainWatchdogActionTypeFromString;
diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
index d89e065e22..ae345fb5fc 100644
--- a/src/qemu/qemu_conf.c
+++ b/src/qemu/qemu_conf.c
@@ -2023,6 +2023,10 @@ qemuAssignDeviceAliases(virDomainDefPtr def, unsigned long long qemuCmdFlags)
         if (virAsprintf(&def->watchdog->info.alias, "watchdog%d", 0) < 0)
             goto no_memory;
     }
+    if (def->memballoon) {
+        if (virAsprintf(&def->memballoon->info.alias, "balloon%d", 0) < 0)
+            goto no_memory;
+    }
 
     return 0;
 
@@ -2296,8 +2300,17 @@ qemuAssignDevicePCISlots(virDomainDefPtr def, qemuDomainPCIAddressSetPtr addrs)
     }
 
     /* VirtIO balloon always at slot 3 by default */
-    if (qemuDomainPCIAddressReserveSlot(addrs, 3) < 0)
-        goto error;
+    if (def->memballoon &&
+        def->memballoon->model == VIR_DOMAIN_MEMBALLOON_MODEL_VIRTIO &&
+        def->memballoon->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE) {
+        def->memballoon->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI;
+        def->memballoon->info.addr.pci.domain = 0;
+        def->memballoon->info.addr.pci.bus = 0;
+        def->memballoon->info.addr.pci.slot = 3;
+        def->memballoon->info.addr.pci.function = 0;
+        if (qemuDomainPCIAddressReserveSlot(addrs, 3) < 0)
+            goto error;
+    }
 
     for (i = 0; i < def->ndisks ; i++) {
         if (def->disks[i]->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE)
@@ -2912,6 +2925,29 @@ error:
 }
 
 
+char *
+qemuBuildMemballoonDevStr(virDomainMemballoonDefPtr dev)
+{
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
+
+    virBufferAddLit(&buf, "virtio-balloon-pci");
+    virBufferVSprintf(&buf, ",id=%s", dev->info.alias);
+    if (qemuBuildDeviceAddressStr(&buf, &dev->info) < 0)
+        goto error;
+
+    if (virBufferError(&buf)) {
+        virReportOOMError();
+        goto error;
+    }
+
+    return virBufferContentAndReset(&buf);
+
+error:
+    virBufferFreeAndReset(&buf);
+    return NULL;
+}
+
+
 char *
 qemuBuildUSBInputDevStr(virDomainInputDefPtr dev)
 {
@@ -4771,12 +4807,25 @@ int qemudBuildCommandLine(virConnectPtr conn,
      * NB: Earlier we declared that VirtIO balloon will always be in
      * slot 0x3 on bus 0x0
      */
-    if (qemuCmdFlags & QEMUD_CMD_FLAG_DEVICE) {
-        ADD_ARG_LIT("-device");
-        ADD_ARG_LIT("virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3");
-    } else if (qemuCmdFlags & QEMUD_CMD_FLAG_BALLOON) {
-        ADD_ARG_LIT("-balloon");
-        ADD_ARG_LIT("virtio");
+    if (def->memballoon) {
+        if (def->memballoon->model != VIR_DOMAIN_MEMBALLOON_MODEL_VIRTIO) {
+            qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                            _("Memory balloon device type '%s' is not supported by this version of qemu"),
+                            virDomainMemballoonModelTypeToString(def->memballoon->model));
+            goto error;
+        }
+        if (qemuCmdFlags & QEMUD_CMD_FLAG_DEVICE) {
+            char *optstr;
+            ADD_ARG_LIT("-device");
+
+            optstr = qemuBuildMemballoonDevStr(def->memballoon);
+            if (!optstr)
+                goto error;
+            ADD_ARG(optstr);
+        } else if (qemuCmdFlags & QEMUD_CMD_FLAG_BALLOON) {
+            ADD_ARG_LIT("-balloon");
+            ADD_ARG_LIT("virtio");
+        }
     }
 
     if (current_snapshot && current_snapshot->def->active) {
@@ -6346,6 +6395,15 @@ virDomainDefPtr qemuParseCommandLine(virCapsPtr caps,
         def->videos[def->nvideos++] = vid;
     }
 
+    if (!def->memballoon) {
+        virDomainMemballoonDefPtr memballoon;
+        if (VIR_ALLOC(memballoon) < 0)
+            goto no_memory;
+        memballoon->model = VIR_DOMAIN_MEMBALLOON_MODEL_VIRTIO;
+
+        def->memballoon = memballoon;
+    }
+
     VIR_FREE(nics);
 
     if (!def->name) {
diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h
index ea10f8592c..ca4559f5f0 100644
--- a/src/qemu/qemu_conf.h
+++ b/src/qemu/qemu_conf.h
@@ -243,6 +243,8 @@ char * qemuBuildControllerDevStr(virDomainControllerDefPtr def);
 
 char * qemuBuildWatchdogDevStr(virDomainWatchdogDefPtr dev);
 
+char * qemuBuildMemballoonDevStr(virDomainMemballoonDefPtr dev);
+
 char * qemuBuildUSBInputDevStr(virDomainInputDefPtr dev);
 
 char * qemuBuildSoundDevStr(virDomainSoundDefPtr sound);
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 92b98479ab..6c7852882f 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -2360,6 +2360,8 @@ cleanup:
 
 #define QEMU_PCI_PRODUCT_DISK_VIRTIO 0x1001
 
+#define QEMU_PCI_PRODUCT_BALLOON_VIRTIO 0x1002
+
 #define QEMU_PCI_PRODUCT_NIC_NE2K     0x8029
 #define QEMU_PCI_PRODUCT_NIC_PCNET    0x2000
 #define QEMU_PCI_PRODUCT_NIC_RTL8139  0x8139
@@ -2568,6 +2570,25 @@ qemuGetPCIWatchdogVendorProduct(virDomainWatchdogDefPtr def,
 }
 
 
+static int
+qemuGetPCIMemballoonVendorProduct(virDomainMemballoonDefPtr def,
+                                  unsigned *vendor,
+                                  unsigned *product)
+{
+    switch (def->model) {
+    case VIR_DOMAIN_MEMBALLOON_MODEL_VIRTIO:
+        *vendor = QEMU_PCI_VENDOR_REDHAT;
+        *product = QEMU_PCI_PRODUCT_BALLOON_VIRTIO;
+        break;
+
+    default:
+        return -1;
+    }
+
+    return 0;
+}
+
+
 /*
  * This entire method assumes that PCI devices in 'info pci'
  * match ordering of devices specified on the command line
@@ -2649,7 +2670,7 @@ qemuDetectPCIAddresses(virDomainObjPtr vm,
             continue;
 
         if (qemuAssignNextPCIAddress(&(vm->def->sounds[i]->info),
-                                     vendor, product,
+                                    vendor, product,
                                      addrs,  naddrs) < 0) {
             qemuReportError(VIR_ERR_INTERNAL_ERROR,
                             _("cannot find PCI address for sound adapter %s"),
@@ -2671,6 +2692,18 @@ qemuDetectPCIAddresses(virDomainObjPtr vm,
         }
     }
 
+    if (vm->def->memballoon &&
+        qemuGetPCIMemballoonVendorProduct(vm->def->memballoon, &vendor, &product) == 0) {
+        if (qemuAssignNextPCIAddress(&(vm->def->memballoon->info),
+                                     vendor, product,
+                                     addrs, naddrs) < 0) {
+            qemuReportError(VIR_ERR_INTERNAL_ERROR,
+                            _("cannot find PCI address for balloon %s"),
+                            virDomainMemballoonModelTypeToString(vm->def->memballoon->model));
+            return -1;
+        }
+    }
+
     /* XXX console (virtio) */
 
 
@@ -2678,8 +2711,6 @@ qemuDetectPCIAddresses(virDomainObjPtr vm,
 
     /* XXX USB controller ? */
 
-    /* XXXX virtio balloon ? */
-
     /* XXX what about other PCI devices (ie bridges) */
 
     return 0;
diff --git a/tests/define-dev-segfault b/tests/define-dev-segfault
index e0b953ad84..7a9a7b6fc6 100755
--- a/tests/define-dev-segfault
+++ b/tests/define-dev-segfault
@@ -59,6 +59,7 @@ cat <<\EOF > D.xml || fail=1
     </console>
     <sound model='pcspk'/>
     <sound model='es1370'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
 EOF
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-balloon-device.args b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device.args
new file mode 100644
index 0000000000..0a481d6bb3
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device.args
@@ -0,0 +1 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -nodefconfig -nodefaults -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -hda /dev/HostVG/QEMUGuest1 -usb -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x12
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-balloon-device.xml b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device.xml
new file mode 100644
index 0000000000..274eb8b008
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device.xml
@@ -0,0 +1,25 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory>219200</memory>
+  <currentMemory>219200</currentMemory>
+  <vcpu>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+    </disk>
+    <memballoon model='virtio'>
+      <address type='pci' domain='0' bus='0' slot='18' function='0'/>
+    </memballoon>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-boot-cdrom.xml b/tests/qemuxml2argvdata/qemuxml2argv-boot-cdrom.xml
index cf0d3df58c..410e6f9551 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-boot-cdrom.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-boot-cdrom.xml
@@ -21,5 +21,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-boot-floppy.xml b/tests/qemuxml2argvdata/qemuxml2argv-boot-floppy.xml
index cf3c5a8fd5..ad8bae226d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-boot-floppy.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-boot-floppy.xml
@@ -26,5 +26,6 @@
     </disk>
     <controller type='fdc' index='0'/>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-boot-network.xml b/tests/qemuxml2argvdata/qemuxml2argv-boot-network.xml
index a28372dc3e..b1b77218d1 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-boot-network.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-boot-network.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-bootloader.xml b/tests/qemuxml2argvdata/qemuxml2argv-bootloader.xml
index 4af280c5f1..af19b3b7a0 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-bootloader.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-bootloader.xml
@@ -21,5 +21,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-channel-guestfwd.xml b/tests/qemuxml2argvdata/qemuxml2argv-channel-guestfwd.xml
index 8963350fad..b3c56b1dcd 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-channel-guestfwd.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-channel-guestfwd.xml
@@ -24,5 +24,6 @@
       <source path='/tmp/guestfwd'/>
       <target type='guestfwd' address='10.0.2.1' port='4600'/>
     </channel>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-channel-virtio-auto.xml b/tests/qemuxml2argvdata/qemuxml2argv-channel-virtio-auto.xml
index 6e3458f1de..afd73f42e7 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-channel-virtio-auto.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-channel-virtio-auto.xml
@@ -47,5 +47,6 @@
       <target type='virtio' name='org.linux-kvm.port.lla'/>
       <address type='virtio-serial' controller='2' bus='0'/>
     </channel>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.xml b/tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.xml
index e597c407e4..2dbb59697f 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.xml
@@ -27,5 +27,6 @@
       <target type='virtio' name='org.linux-kvm.port.foo'/>
       <address type='virtio-serial' controller='1' bus='0' port='3'/>
     </channel>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-clock-france.xml b/tests/qemuxml2argvdata/qemuxml2argv-clock-france.xml
index 157fdfb3de..8794492300 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-clock-france.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-clock-france.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-clock-localtime.xml b/tests/qemuxml2argvdata/qemuxml2argv-clock-localtime.xml
index 345ae22e9b..786d0c70e8 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-clock-localtime.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-clock-localtime.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-clock-utc.xml b/tests/qemuxml2argvdata/qemuxml2argv-clock-utc.xml
index 533ea59b30..ed91e37a12 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-clock-utc.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-clock-utc.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-clock-variable.xml b/tests/qemuxml2argvdata/qemuxml2argv-clock-variable.xml
index fa20b27374..41818d25eb 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-clock-variable.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-clock-variable.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-console-compat-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-console-compat-chardev.xml
index df694c78cd..611ddb8d7b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-console-compat-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-console-compat-chardev.xml
@@ -26,5 +26,6 @@
     <console type='pty'>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-console-compat.xml b/tests/qemuxml2argvdata/qemuxml2argv-console-compat.xml
index df694c78cd..611ddb8d7b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-console-compat.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-console-compat.xml
@@ -26,5 +26,6 @@
     <console type='pty'>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-cdrom-empty.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-cdrom-empty.xml
index addbbf1166..1b18d613d1 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-cdrom-empty.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-cdrom-empty.xml
@@ -25,5 +25,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-cdrom.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-cdrom.xml
index 9c10551c41..061b196ba9 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-cdrom.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-cdrom.xml
@@ -26,5 +26,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-boot-cdrom.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-boot-cdrom.xml
index 736e189e7c..0994a4986e 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-boot-cdrom.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-boot-cdrom.xml
@@ -25,5 +25,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-boot-disk.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-boot-disk.xml
index c379f31855..9762f5aef4 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-boot-disk.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-boot-disk.xml
@@ -25,5 +25,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-none.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-none.xml
index e689d9cad2..0b2f512ecd 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-none.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-none.xml
@@ -28,5 +28,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-wb.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-wb.xml
index be00c4c81c..a43808618d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-wb.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-wb.xml
@@ -28,5 +28,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-wt.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-wt.xml
index edf776a399..29012a854d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-wt.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v1-wt.xml
@@ -28,5 +28,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-none.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-none.xml
index e689d9cad2..0b2f512ecd 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-none.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-none.xml
@@ -28,5 +28,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-wb.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-wb.xml
index be00c4c81c..a43808618d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-wb.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-wb.xml
@@ -28,5 +28,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-wt.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-wt.xml
index edf776a399..29012a854d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-wt.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-cache-v2-wt.xml
@@ -28,5 +28,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-enospace.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-enospace.xml
index 8fe64d4bdf..b3e6de9947 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-enospace.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-enospace.xml
@@ -28,5 +28,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-stop.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-stop.xml
index 67e23ccfe4..a4865026eb 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-stop.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-stop.xml
@@ -28,5 +28,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-fat.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-fat.xml
index b2b1b4ec1e..a3491e770b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-fat.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-fat.xml
@@ -22,5 +22,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-fmt-qcow.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-fmt-qcow.xml
index 0b04e69d90..f2643bb09e 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-fmt-qcow.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-fmt-qcow.xml
@@ -28,5 +28,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-readonly-disk.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-readonly-disk.xml
index 39c3a1ccfe..1f193c93cb 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-readonly-disk.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-readonly-disk.xml
@@ -26,5 +26,6 @@
        <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.xml
index 47afcd710c..27e741ae84 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.xml
@@ -30,5 +30,6 @@
       <address type='drive' controller='0' bus='1' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-floppy.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-floppy.xml
index 35474beb1e..c0a4a08384 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-floppy.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-floppy.xml
@@ -31,5 +31,6 @@
     </disk>
     <controller type='fdc' index='0'/>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-many.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-many.xml
index 467fa5d65b..14f85cc72d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-many.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-many.xml
@@ -35,5 +35,6 @@
       <address type='drive' controller='0' bus='1' unit='1'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-usb-device.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-usb-device.xml
index d59e1c0a27..6d35eea5fc 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-usb-device.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-usb-device.xml
@@ -22,5 +22,6 @@
       <source file='/tmp/usbdisk.img'/>
       <target dev='sda' bus='usb'/>
     </disk>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-usb.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-usb.xml
index 8148626ad5..79ab65422b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-usb.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-usb.xml
@@ -24,5 +24,6 @@
       <target dev='sda' bus='usb'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.xml
index 23930731f2..a8aae71b39 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-virtio.xml
@@ -34,5 +34,6 @@
       <target dev='vdb' bus='virtio'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-xenvbd.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-xenvbd.xml
index 0c36457601..a3dd4c637b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-xenvbd.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-xenvbd.xml
@@ -34,5 +34,6 @@
       <target dev='xvdg' bus='xen'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-encrypted-disk.xml b/tests/qemuxml2argvdata/qemuxml2argv-encrypted-disk.xml
index cb7b06d3d3..f5e5d74a89 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-encrypted-disk.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-encrypted-disk.xml
@@ -23,5 +23,6 @@
       </encryption>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
     </disk>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-floppy-drive-fat.xml b/tests/qemuxml2argvdata/qemuxml2argv-floppy-drive-fat.xml
index 6da210d097..ec74bdddd6 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-floppy-drive-fat.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-floppy-drive-fat.xml
@@ -23,5 +23,6 @@
     </disk>
     <controller type='ide' index='0'/>
     <controller type='fdc' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl-fullscreen.xml b/tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl-fullscreen.xml
index dcecd47d3d..06b0539894 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl-fullscreen.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl-fullscreen.xml
@@ -25,5 +25,6 @@
     <video>
       <model type='cirrus' vram='9216' heads='1'/>
     </video>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl.xml b/tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl.xml
index f691bfeca5..16fd3badd4 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-graphics-sdl.xml
@@ -25,5 +25,6 @@
     <video>
       <model type='vga' vram='9216' heads='1'/>
     </video>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-sasl.xml b/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-sasl.xml
index da0f3c68af..a07f87b139 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-sasl.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-sasl.xml
@@ -25,5 +25,6 @@
     <video>
       <model type='cirrus' vram='9216' heads='1'/>
     </video>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-tls.xml b/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-tls.xml
index da0f3c68af..a07f87b139 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-tls.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc-tls.xml
@@ -25,5 +25,6 @@
     <video>
       <model type='cirrus' vram='9216' heads='1'/>
     </video>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.xml b/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.xml
index da0f3c68af..a07f87b139 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-graphics-vnc.xml
@@ -25,5 +25,6 @@
     <video>
       <model type='cirrus' vram='9216' heads='1'/>
     </video>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-hostdev-pci-address-device.xml b/tests/qemuxml2argvdata/qemuxml2argv-hostdev-pci-address-device.xml
index ac5ad47eca..711e3f8ca9 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-hostdev-pci-address-device.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-hostdev-pci-address-device.xml
@@ -23,5 +23,6 @@
         <address domain='0x0000' bus='0x06' slot='0x12' function='0x5'/>
       </source>
     </hostdev>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-hostdev-pci-address.xml b/tests/qemuxml2argvdata/qemuxml2argv-hostdev-pci-address.xml
index cb039af783..0347eeea19 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-hostdev-pci-address.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-hostdev-pci-address.xml
@@ -25,5 +25,6 @@
         <address domain='0x0000' bus='0x06' slot='0x12' function='0x5'/>
       </source>
     </hostdev>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address-device.xml b/tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address-device.xml
index 61bb2a2b2a..da2562e825 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address-device.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address-device.xml
@@ -23,5 +23,6 @@
         <address bus='14' device='6'/>
       </source>
     </hostdev>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address.xml b/tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address.xml
index c7d0d919f3..4391bf108e 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-hostdev-usb-address.xml
@@ -25,5 +25,6 @@
         <address bus='14' device='6'/>
       </source>
     </hostdev>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-hugepages.xml b/tests/qemuxml2argvdata/qemuxml2argv-hugepages.xml
index 2e4b75fa68..8ed7490eca 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-hugepages.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-hugepages.xml
@@ -23,5 +23,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-input-usbmouse.xml b/tests/qemuxml2argvdata/qemuxml2argv-input-usbmouse.xml
index 8603d1bcba..b76a895ee4 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-input-usbmouse.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-input-usbmouse.xml
@@ -21,5 +21,6 @@
     </disk>
     <controller type='ide' index='0'/>
     <input type='mouse' bus='usb'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-input-usbtablet.xml b/tests/qemuxml2argvdata/qemuxml2argv-input-usbtablet.xml
index 6c2a41b70a..a878f8c9a6 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-input-usbtablet.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-input-usbtablet.xml
@@ -21,5 +21,6 @@
     </disk>
     <controller type='ide' index='0'/>
     <input type='tablet' bus='usb'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-input-xen.xml b/tests/qemuxml2argvdata/qemuxml2argv-input-xen.xml
index 91dd79524c..0ea00c1bef 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-input-xen.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-input-xen.xml
@@ -25,5 +25,6 @@
     <video>
       <model type='xen' vram='4096' heads='1'/>
     </video>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-machine-aliases1.xml b/tests/qemuxml2argvdata/qemuxml2argv-machine-aliases1.xml
index 268954d0d9..9f3fc85ea8 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-machine-aliases1.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-machine-aliases1.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-machine-aliases2.xml b/tests/qemuxml2argvdata/qemuxml2argv-machine-aliases2.xml
index 354b1d5d7c..c57e64ce02 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-machine-aliases2.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-machine-aliases2.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-migrate.xml b/tests/qemuxml2argvdata/qemuxml2argv-migrate.xml
index 533ea59b30..ed91e37a12 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-migrate.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-migrate.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-minimal.xml b/tests/qemuxml2argvdata/qemuxml2argv-minimal.xml
index 334a9f99c3..8a13e47428 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-minimal.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-minimal.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-misc-acpi.xml b/tests/qemuxml2argvdata/qemuxml2argv-misc-acpi.xml
index 474832d053..c8e87b058d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-misc-acpi.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-misc-acpi.xml
@@ -23,5 +23,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-misc-no-reboot.xml b/tests/qemuxml2argvdata/qemuxml2argv-misc-no-reboot.xml
index f75722ffcc..bb4f5f05a3 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-misc-no-reboot.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-misc-no-reboot.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-misc-uuid.xml b/tests/qemuxml2argvdata/qemuxml2argv-misc-uuid.xml
index 474832d053..c8e87b058d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-misc-uuid.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-misc-uuid.xml
@@ -23,5 +23,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-eth-ifname.xml b/tests/qemuxml2argvdata/qemuxml2argv-net-eth-ifname.xml
index e24cd997ba..516957fc02 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-eth-ifname.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-eth-ifname.xml
@@ -25,5 +25,6 @@
       <script path='/etc/qemu-ifup'/>
       <target dev='nic02'/>
     </interface>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-eth-names.xml b/tests/qemuxml2argvdata/qemuxml2argv-net-eth-names.xml
index 105d3f6292..7875d0ccf8 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-eth-names.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-eth-names.xml
@@ -29,5 +29,6 @@
       <script path='/etc/qemu-ifup'/>
       <model type='e1000'/>
     </interface>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-eth.xml b/tests/qemuxml2argvdata/qemuxml2argv-net-eth.xml
index 27238fc75a..5d410b3753 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-eth.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-eth.xml
@@ -24,5 +24,6 @@
       <mac address='00:11:22:33:44:55'/>
       <script path='/etc/qemu-ifup'/>
     </interface>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-user.xml b/tests/qemuxml2argvdata/qemuxml2argv-net-user.xml
index 525593dc8c..ffc4a2ceb9 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-user.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-user.xml
@@ -23,5 +23,6 @@
     <interface type='user'>
       <mac address='00:11:22:33:44:55'/>
     </interface>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-device.xml b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-device.xml
index 5d34bd492c..e521796f9d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-device.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-device.xml
@@ -22,5 +22,6 @@
       <mac address='00:11:22:33:44:55'/>
       <model type='virtio'/>
     </interface>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-netdev.xml b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-netdev.xml
index 5d34bd492c..e521796f9d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-netdev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-netdev.xml
@@ -22,5 +22,6 @@
       <mac address='00:11:22:33:44:55'/>
       <model type='virtio'/>
     </interface>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio.xml b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio.xml
index f8d9acfb6f..9b9c059ad0 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio.xml
@@ -24,5 +24,6 @@
       <mac address='00:11:22:33:44:55'/>
       <model type='virtio'/>
     </interface>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-nographics-vga.xml b/tests/qemuxml2argvdata/qemuxml2argv-nographics-vga.xml
index 533ea59b30..ed91e37a12 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-nographics-vga.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-nographics-vga.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-parallel-tcp-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-parallel-tcp-chardev.xml
index 96a1ca5a17..1093901da1 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-parallel-tcp-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-parallel-tcp-chardev.xml
@@ -25,5 +25,6 @@
       <protocol type='raw'/>
       <target port='0'/>
     </parallel>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-parallel-tcp.xml b/tests/qemuxml2argvdata/qemuxml2argv-parallel-tcp.xml
index 96a1ca5a17..1093901da1 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-parallel-tcp.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-parallel-tcp.xml
@@ -25,5 +25,6 @@
       <protocol type='raw'/>
       <target port='0'/>
     </parallel>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-restore-v1.xml b/tests/qemuxml2argvdata/qemuxml2argv-restore-v1.xml
index 533ea59b30..ed91e37a12 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-restore-v1.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-restore-v1.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-restore-v2.xml b/tests/qemuxml2argvdata/qemuxml2argv-restore-v2.xml
index 533ea59b30..ed91e37a12 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-restore-v2.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-restore-v2.xml
@@ -20,5 +20,6 @@
       <address type='drive' controller='0' bus='0' unit='0'/>
     </disk>
     <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-dev-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-dev-chardev.xml
index ae906c25bc..5d24986341 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-dev-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-dev-chardev.xml
@@ -28,5 +28,6 @@
       <source path='/dev/ttyS2'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-dev.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-dev.xml
index ae906c25bc..5d24986341 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-dev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-dev.xml
@@ -28,5 +28,6 @@
       <source path='/dev/ttyS2'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-file-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-file-chardev.xml
index bdc483ffc7..98bc4ef70f 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-file-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-file-chardev.xml
@@ -28,5 +28,6 @@
       <source path='/tmp/serial.log'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-file.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-file.xml
index bdc483ffc7..98bc4ef70f 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-file.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-file.xml
@@ -28,5 +28,6 @@
       <source path='/tmp/serial.log'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-many-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-many-chardev.xml
index 38a9498faa..b121c5c72f 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-many-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-many-chardev.xml
@@ -30,5 +30,6 @@
     <console type='pty'>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-many.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-many.xml
index 38a9498faa..b121c5c72f 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-many.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-many.xml
@@ -30,5 +30,6 @@
     <console type='pty'>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-pty-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-pty-chardev.xml
index df694c78cd..611ddb8d7b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-pty-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-pty-chardev.xml
@@ -26,5 +26,6 @@
     <console type='pty'>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-pty.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-pty.xml
index df694c78cd..611ddb8d7b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-pty.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-pty.xml
@@ -26,5 +26,6 @@
     <console type='pty'>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-chardev.xml
index a8a3526713..286417e181 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-chardev.xml
@@ -30,5 +30,6 @@
       <protocol type='raw'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-telnet-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-telnet-chardev.xml
index fb8004214e..5aeceb0e8c 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-telnet-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-telnet-chardev.xml
@@ -30,5 +30,6 @@
       <protocol type='telnet'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-telnet.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-telnet.xml
index fb8004214e..5aeceb0e8c 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-telnet.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp-telnet.xml
@@ -30,5 +30,6 @@
       <protocol type='telnet'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp.xml
index a8a3526713..286417e181 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-tcp.xml
@@ -30,5 +30,6 @@
       <protocol type='raw'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-udp-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-udp-chardev.xml
index 01dba47c88..2c447389d5 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-udp-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-udp-chardev.xml
@@ -30,5 +30,6 @@
       <source mode='connect' host='127.0.0.1' service='9998'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-udp.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-udp.xml
index 01dba47c88..2c447389d5 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-udp.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-udp.xml
@@ -30,5 +30,6 @@
       <source mode='connect' host='127.0.0.1' service='9998'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-unix-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-unix-chardev.xml
index 7b90d7b3c5..2c07e94a0a 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-unix-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-unix-chardev.xml
@@ -28,5 +28,6 @@
       <source mode='connect' path='/tmp/serial.sock'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-unix.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-unix.xml
index 7b90d7b3c5..2c07e94a0a 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-unix.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-unix.xml
@@ -28,5 +28,6 @@
       <source mode='connect' path='/tmp/serial.sock'/>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-vc-chardev.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-vc-chardev.xml
index 76b3e2abc8..5b39736d5b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-vc-chardev.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-vc-chardev.xml
@@ -26,5 +26,6 @@
     <console type='vc'>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-serial-vc.xml b/tests/qemuxml2argvdata/qemuxml2argv-serial-vc.xml
index 76b3e2abc8..5b39736d5b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-serial-vc.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-serial-vc.xml
@@ -26,5 +26,6 @@
     <console type='vc'>
       <target port='0'/>
     </console>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-sound-device.xml b/tests/qemuxml2argvdata/qemuxml2argv-sound-device.xml
index 8c33e6c90a..c7253462b2 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-sound-device.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-sound-device.xml
@@ -22,5 +22,6 @@
     <sound model='es1370'/>
     <sound model='sb16'/>
     <sound model='ac97'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-sound.xml b/tests/qemuxml2argvdata/qemuxml2argv-sound.xml
index 85f81cefaf..d34e0b3411 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-sound.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-sound.xml
@@ -24,5 +24,6 @@
     <sound model='es1370'/>
     <sound model='sb16'/>
     <sound model='ac97'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-watchdog-device.xml b/tests/qemuxml2argvdata/qemuxml2argv-watchdog-device.xml
index 9b2ffdf8b2..2dfc37e22e 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-watchdog-device.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-watchdog-device.xml
@@ -19,5 +19,6 @@
       <target dev='hda' bus='ide'/>
     </disk>
     <watchdog model='ib700' action='poweroff'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-watchdog.xml b/tests/qemuxml2argvdata/qemuxml2argv-watchdog.xml
index 07d2c14269..804dfd8935 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-watchdog.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-watchdog.xml
@@ -21,5 +21,6 @@
     </disk>
     <controller type='ide' index='0'/>
     <watchdog model='ib700' action='poweroff'/>
+    <memballoon model='virtio'/>
   </devices>
 </domain>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index ad1379b5c6..24002b8f17 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -352,6 +352,8 @@ mymain(int argc, char **argv)
     DO_TEST("watchdog", 0);
     DO_TEST("watchdog-device", QEMUD_CMD_FLAG_DEVICE |
             QEMUD_CMD_FLAG_NODEFCONFIG);
+    DO_TEST("balloon-device", QEMUD_CMD_FLAG_DEVICE |
+            QEMUD_CMD_FLAG_NODEFCONFIG);
     DO_TEST("sound", 0);
     DO_TEST("sound-device", QEMUD_CMD_FLAG_DEVICE |
             QEMUD_CMD_FLAG_NODEFCONFIG);