From 546154e3d4ea5b16491365c63419f92a9981bb1f Mon Sep 17 00:00:00 2001
From: Jiri Denemark <jdenemar@redhat.com>
Date: Thu, 17 Apr 2014 15:22:32 +0200
Subject: [PATCH] conf: Format and parse backing chains in domain XML

This patch implements formating and parsing code for the backing store
schema defined and documented by the previous patch.

This patch does not aim at providing full persistent storage of disk
backing chains yet. The formatter is supposed to provide the backing
chain detected when starting a domain and thus it is not formatted into
an inactive domain XML. The parser is implemented mainly for the purpose
of testing the XML generated by the formatter and thus it does not
distinguish between no backingStore element and an empty backingStore
element. This will have to change once we fully implement support for
user-supplied backing chains.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/conf/domain_conf.c                        | 128 ++++++++++++++++++
 .../qemuxml2argv-disk-mirror.xml              |   4 +
 ...qemuxml2argv-seclabel-static-labelskip.xml |   1 +
 tests/sexpr2xmldata/sexpr2xml-boot-grub.xml   |   1 +
 .../sexpr2xmldata/sexpr2xml-bridge-ipaddr.xml |   1 +
 tests/sexpr2xmldata/sexpr2xml-curmem.xml      |   1 +
 .../sexpr2xml-disk-block-shareable.xml        |   1 +
 tests/sexpr2xmldata/sexpr2xml-disk-block.xml  |   1 +
 .../sexpr2xml-disk-drv-blktap-qcow.xml        |   1 +
 .../sexpr2xml-disk-drv-blktap-raw.xml         |   1 +
 .../sexpr2xml-disk-drv-blktap2-raw.xml        |   1 +
 tests/sexpr2xmldata/sexpr2xml-disk-file.xml   |   1 +
 tests/sexpr2xmldata/sexpr2xml-fv-autoport.xml |   2 +
 .../sexpr2xml-fv-empty-kernel.xml             |   2 +
 .../sexpr2xmldata/sexpr2xml-fv-force-hpet.xml |   2 +
 .../sexpr2xml-fv-force-nohpet.xml             |   2 +
 tests/sexpr2xmldata/sexpr2xml-fv-kernel.xml   |   1 +
 .../sexpr2xmldata/sexpr2xml-fv-legacy-vfb.xml |   1 +
 .../sexpr2xmldata/sexpr2xml-fv-localtime.xml  |   2 +
 .../sexpr2xmldata/sexpr2xml-fv-net-ioemu.xml  |   2 +
 .../sexpr2xml-fv-net-netfront.xml             |   2 +
 .../sexpr2xml-fv-parallel-tcp.xml             |   2 +
 .../sexpr2xml-fv-serial-dev-2-ports.xml       |   2 +
 .../sexpr2xml-fv-serial-dev-2nd-port.xml      |   2 +
 .../sexpr2xml-fv-serial-file.xml              |   2 +
 .../sexpr2xml-fv-serial-null.xml              |   2 +
 .../sexpr2xml-fv-serial-pipe.xml              |   2 +
 .../sexpr2xmldata/sexpr2xml-fv-serial-pty.xml |   2 +
 .../sexpr2xml-fv-serial-stdio.xml             |   2 +
 .../sexpr2xml-fv-serial-tcp-telnet.xml        |   2 +
 .../sexpr2xmldata/sexpr2xml-fv-serial-tcp.xml |   2 +
 .../sexpr2xmldata/sexpr2xml-fv-serial-udp.xml |   2 +
 .../sexpr2xml-fv-serial-unix.xml              |   2 +
 .../sexpr2xmldata/sexpr2xml-fv-sound-all.xml  |   2 +
 tests/sexpr2xmldata/sexpr2xml-fv-sound.xml    |   2 +
 tests/sexpr2xmldata/sexpr2xml-fv-usbmouse.xml |   2 +
 .../sexpr2xmldata/sexpr2xml-fv-usbtablet.xml  |   2 +
 tests/sexpr2xmldata/sexpr2xml-fv-utc.xml      |   2 +
 tests/sexpr2xmldata/sexpr2xml-fv-v2.xml       |   2 +
 tests/sexpr2xmldata/sexpr2xml-fv.xml          |   2 +
 tests/sexpr2xmldata/sexpr2xml-net-bridged.xml |   1 +
 tests/sexpr2xmldata/sexpr2xml-net-e1000.xml   |   1 +
 tests/sexpr2xmldata/sexpr2xml-net-routed.xml  |   1 +
 .../sexpr2xml-no-source-cdrom.xml             |   2 +
 tests/sexpr2xmldata/sexpr2xml-pci-devs.xml    |   1 +
 .../sexpr2xml-pv-bootloader-cmdline.xml       |   1 +
 .../sexpr2xmldata/sexpr2xml-pv-bootloader.xml |   1 +
 .../sexpr2xmldata/sexpr2xml-pv-localtime.xml  |   1 +
 tests/sexpr2xmldata/sexpr2xml-pv-vcpus.xml    |   1 +
 .../sexpr2xml-pv-vfb-new-vncdisplay.xml       |   1 +
 tests/sexpr2xmldata/sexpr2xml-pv-vfb-new.xml  |   1 +
 tests/sexpr2xmldata/sexpr2xml-pv-vfb-orig.xml |   1 +
 .../sexpr2xml-pv-vfb-type-crash.xml           |   1 +
 tests/sexpr2xmldata/sexpr2xml-pv.xml          |   1 +
 54 files changed, 211 insertions(+)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index b7781c9586..a558b1bad7 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -5084,6 +5084,74 @@ virDomainDiskSourceParse(xmlNodePtr node,
 }
 
 
+static int
+virDomainDiskBackingStoreParse(xmlXPathContextPtr ctxt,
+                               virStorageSourcePtr src)
+{
+    virStorageSourcePtr backingStore = NULL;
+    xmlNodePtr save_ctxt = ctxt->node;
+    xmlNodePtr source;
+    char *type = NULL;
+    char *format = NULL;
+    int ret = -1;
+
+    if (!(ctxt->node = virXPathNode("./backingStore[*]", ctxt))) {
+        ret = 0;
+        goto cleanup;
+    }
+
+    if (VIR_ALLOC(backingStore) < 0)
+        goto cleanup;
+
+    if (!(type = virXMLPropString(ctxt->node, "type"))) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("missing disk backing store type"));
+        goto cleanup;
+    }
+
+    backingStore->type = virStorageTypeFromString(type);
+    if (backingStore->type < 0) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("unknown disk backing store type '%s'"), type);
+        goto cleanup;
+    }
+
+    if (!(format = virXPathString("string(./format/@type)", ctxt))) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("missing disk backing store format"));
+        goto cleanup;
+    }
+
+    backingStore->format = virStorageFileFormatTypeFromString(format);
+    if (backingStore->format < 0) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("unknown disk backing store format '%s'"), format);
+        goto cleanup;
+    }
+
+    if (!(source = virXPathNode("./source", ctxt))) {
+        virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("missing disk backing store source"));
+        goto cleanup;
+    }
+
+    if (virDomainDiskSourceParse(source, backingStore) < 0 ||
+        virDomainDiskBackingStoreParse(ctxt, backingStore) < 0)
+        goto cleanup;
+
+    src->backingStore = backingStore;
+    ret = 0;
+
+ cleanup:
+    if (ret < 0)
+        virStorageSourceFree(backingStore);
+    VIR_FREE(type);
+    VIR_FREE(format);
+    ctxt->node = save_ctxt;
+    return ret;
+}
+
+
 #define VENDOR_LEN  8
 #define PRODUCT_LEN 16
 
@@ -5842,6 +5910,9 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
         && virDomainDiskDefAssignAddress(xmlopt, def) < 0)
         goto error;
 
+    if (virDomainDiskBackingStoreParse(ctxt, &def->src) < 0)
+        goto error;
+
  cleanup:
     VIR_FREE(bus);
     VIR_FREE(type);
@@ -14862,6 +14933,55 @@ virDomainDiskSourceFormat(virBufferPtr buf,
 }
 
 
+static int
+virDomainDiskBackingStoreFormat(virBufferPtr buf,
+                                virStorageSourcePtr backingStore,
+                                const char *backingStoreRaw,
+                                unsigned int index)
+{
+    const char *type;
+    const char *format;
+
+    if (!backingStore) {
+        if (!backingStoreRaw)
+            virBufferAddLit(buf, "<backingStore/>\n");
+        return 0;
+    }
+
+    if (!backingStore->type ||
+        !(type = virStorageTypeToString(backingStore->type))) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("unexpected disk backing store type %d"),
+                       backingStore->type);
+        return -1;
+    }
+
+    if (backingStore->format <= 0 ||
+        !(format = virStorageFileFormatTypeToString(backingStore->format))) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("unexpected disk backing store format %d"),
+                       backingStore->format);
+        return -1;
+    }
+
+    virBufferAsprintf(buf, "<backingStore type='%s' index='%u'>\n",
+                      type, index);
+    virBufferAdjustIndent(buf, 2);
+
+    virBufferAsprintf(buf, "<format type='%s'/>\n", format);
+    if (virDomainDiskSourceFormat(buf, backingStore, 0, 0) < 0 ||
+        virDomainDiskBackingStoreFormat(buf,
+                                        backingStore->backingStore,
+                                        backingStore->backingStoreRaw,
+                                        index + 1) < 0)
+        return -1;
+
+    virBufferAdjustIndent(buf, -2);
+    virBufferAddLit(buf, "</backingStore>\n");
+    return 0;
+}
+
+
 static int
 virDomainDiskDefFormat(virBufferPtr buf,
                        virDomainDiskDefPtr def,
@@ -14988,6 +15108,14 @@ virDomainDiskDefFormat(virBufferPtr buf,
     if (virDomainDiskSourceFormat(buf, &def->src, def->startupPolicy,
                                   flags) < 0)
         return -1;
+
+    /* Don't format backingStore to inactive XMLs until the code for
+     * persistent storage of backing chains is ready. */
+    if (!(flags & VIR_DOMAIN_XML_INACTIVE) &&
+        virDomainDiskBackingStoreFormat(buf, def->src.backingStore,
+                                        def->src.backingStoreRaw, 1) < 0)
+        return -1;
+
     virDomainDiskGeometryDefFormat(buf, def);
     virDomainDiskBlockIoDefFormat(buf, def);
 
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml
index aa16a7e399..faa0b8c4a1 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-mirror.xml
@@ -16,23 +16,27 @@
     <emulator>/usr/bin/qemu</emulator>
     <disk type='block' device='disk'>
       <source dev='/dev/HostVG/QEMUGuest1'/>
+      <backingStore/>
       <mirror file='/dev/HostVG/QEMUGuest1Copy' ready='yes'/>
       <target dev='hda' bus='ide'/>
       <address type='drive' controller='0' bus='0' target='0' unit='0'/>
     </disk>
     <disk type='block' device='cdrom'>
       <source dev='/dev/HostVG/QEMUGuest2'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
       <address type='drive' controller='0' bus='1' target='0' unit='0'/>
     </disk>
     <disk type='file' device='disk'>
       <source file='/tmp/data.img'/>
+      <backingStore/>
       <mirror file='/tmp/copy.img' format='qcow2'/>
       <target dev='vda' bus='virtio'/>
     </disk>
     <disk type='file' device='disk'>
       <source file='/tmp/logs.img'/>
+      <backingStore/>
       <target dev='vdb' bus='virtio'/>
     </disk>
     <controller type='usb' index='0'/>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-seclabel-static-labelskip.xml b/tests/qemuxml2argvdata/qemuxml2argv-seclabel-static-labelskip.xml
index a7434481db..7978f5bc1e 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-seclabel-static-labelskip.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-seclabel-static-labelskip.xml
@@ -18,6 +18,7 @@
       <source dev='/dev/HostVG/QEMUGuest1'>
         <seclabel model='selinux' labelskip='yes'/>
       </source>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
       <address type='drive' controller='0' bus='0' target='0' unit='0'/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-boot-grub.xml b/tests/sexpr2xmldata/sexpr2xml-boot-grub.xml
index cc3fd48ed0..1220407f34 100644
--- a/tests/sexpr2xmldata/sexpr2xml-boot-grub.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-boot-grub.xml
@@ -17,6 +17,7 @@
     <disk type='block' device='disk'>
       <driver name='phy'/>
       <source dev='/dev/MainVG/GuestVG'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-bridge-ipaddr.xml b/tests/sexpr2xmldata/sexpr2xml-bridge-ipaddr.xml
index e17e1e5a5d..9b5cc3a49b 100644
--- a/tests/sexpr2xmldata/sexpr2xml-bridge-ipaddr.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-bridge-ipaddr.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <interface type='bridge'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-curmem.xml b/tests/sexpr2xmldata/sexpr2xml-curmem.xml
index 2e68fc464d..39d954a223 100644
--- a/tests/sexpr2xmldata/sexpr2xml-curmem.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-curmem.xml
@@ -19,6 +19,7 @@
     <disk type='file' device='disk'>
       <driver name='tap' type='raw'/>
       <source file='/xen/rhel5.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <interface type='bridge'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-disk-block-shareable.xml b/tests/sexpr2xmldata/sexpr2xml-disk-block-shareable.xml
index 571b349068..40e890390c 100644
--- a/tests/sexpr2xmldata/sexpr2xml-disk-block-shareable.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-disk-block-shareable.xml
@@ -16,6 +16,7 @@
     <disk type='file' device='disk'>
       <driver name='tap' type='raw'/>
       <source file='/var/lib/xen/images/rhel5pv.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
       <shareable/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-disk-block.xml b/tests/sexpr2xmldata/sexpr2xml-disk-block.xml
index 77165765ae..51e3b3a9d2 100644
--- a/tests/sexpr2xmldata/sexpr2xml-disk-block.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-disk-block.xml
@@ -18,6 +18,7 @@
     <disk type='block' device='disk'>
       <driver name='phy'/>
       <source dev='/dev/MainVG/GuestVG'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap-qcow.xml b/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap-qcow.xml
index 38ae2fe80d..315c68a647 100644
--- a/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap-qcow.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap-qcow.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='tap' type='qcow'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap-raw.xml b/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap-raw.xml
index df8e7ecb2e..c56582da5b 100644
--- a/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap-raw.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap-raw.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='tap' type='raw'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap2-raw.xml b/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap2-raw.xml
index ea93195c8d..7afc6b50cb 100644
--- a/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap2-raw.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-disk-drv-blktap2-raw.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='tap2' type='raw'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-disk-file.xml b/tests/sexpr2xmldata/sexpr2xml-disk-file.xml
index 7496539478..36b8c1eb6b 100644
--- a/tests/sexpr2xmldata/sexpr2xml-disk-file.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-disk-file.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-autoport.xml b/tests/sexpr2xmldata/sexpr2xml-fv-autoport.xml
index 0f29f03f52..69fe9ef8b8 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-autoport.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-autoport.xml
@@ -21,11 +21,13 @@
     <disk type='block' device='disk'>
       <driver name='phy'/>
       <source dev='/iscsi/winxp'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/net/heaped/export/netimage/windows/xp-sp2-vol.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-empty-kernel.xml b/tests/sexpr2xmldata/sexpr2xml-fv-empty-kernel.xml
index b5bd19b815..3c3147d725 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-empty-kernel.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-empty-kernel.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-force-hpet.xml b/tests/sexpr2xmldata/sexpr2xml-fv-force-hpet.xml
index ae056c8490..716f16b4c2 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-force-hpet.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-force-hpet.xml
@@ -23,11 +23,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-force-nohpet.xml b/tests/sexpr2xmldata/sexpr2xml-fv-force-nohpet.xml
index 27090be17d..3dd648b894 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-force-nohpet.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-force-nohpet.xml
@@ -23,11 +23,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-kernel.xml b/tests/sexpr2xmldata/sexpr2xml-fv-kernel.xml
index 320835a5db..29c1335bad 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-kernel.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-kernel.xml
@@ -19,6 +19,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <serial type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-legacy-vfb.xml b/tests/sexpr2xmldata/sexpr2xml-fv-legacy-vfb.xml
index d28ba98807..9c596448a4 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-legacy-vfb.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-legacy-vfb.xml
@@ -26,6 +26,7 @@
     <disk type='block' device='disk'>
       <driver name='phy'/>
       <source dev='/dev/zvol/dsk/export/s10u4-root'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <input type='mouse' bus='ps2'/>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-localtime.xml b/tests/sexpr2xmldata/sexpr2xml-fv-localtime.xml
index b896e51a07..67b0b95cac 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-localtime.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-localtime.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-net-ioemu.xml b/tests/sexpr2xmldata/sexpr2xml-fv-net-ioemu.xml
index 8dda7ffc7d..86b32e9257 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-net-ioemu.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-net-ioemu.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-net-netfront.xml b/tests/sexpr2xmldata/sexpr2xml-fv-net-netfront.xml
index 788d319df7..ed7da80d77 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-net-netfront.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-net-netfront.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-parallel-tcp.xml b/tests/sexpr2xmldata/sexpr2xml-fv-parallel-tcp.xml
index a9450ec271..ed3fde64e3 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-parallel-tcp.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-parallel-tcp.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-dev-2-ports.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-dev-2-ports.xml
index f05db8d2af..7f5a729b5c 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-dev-2-ports.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-dev-2-ports.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-dev-2nd-port.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-dev-2nd-port.xml
index 10a331ea4e..10f84dc882 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-dev-2nd-port.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-dev-2nd-port.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-file.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-file.xml
index c1c717e18d..a3fd2311da 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-file.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-file.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-null.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-null.xml
index ea19144050..b3f77c97dc 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-null.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-null.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-pipe.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-pipe.xml
index 447d4a36f4..e2171613e7 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-pipe.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-pipe.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-pty.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-pty.xml
index 328bc45a0f..3ad22649c4 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-pty.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-pty.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-stdio.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-stdio.xml
index 5a92433219..001df567e8 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-stdio.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-stdio.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-tcp-telnet.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-tcp-telnet.xml
index 1f800bc823..c2496fde63 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-tcp-telnet.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-tcp-telnet.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-tcp.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-tcp.xml
index 23dabbdb8e..6dc047ecd9 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-tcp.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-tcp.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-udp.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-udp.xml
index 29ba6e58a2..7ccaeacf7f 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-udp.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-udp.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-serial-unix.xml b/tests/sexpr2xmldata/sexpr2xml-fv-serial-unix.xml
index 0379e0d9ee..b5ad4134e1 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-serial-unix.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-serial-unix.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-sound-all.xml b/tests/sexpr2xmldata/sexpr2xml-fv-sound-all.xml
index 0785041e82..7183e792c8 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-sound-all.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-sound-all.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-sound.xml b/tests/sexpr2xmldata/sexpr2xml-fv-sound.xml
index 0785041e82..7183e792c8 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-sound.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-sound.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-usbmouse.xml b/tests/sexpr2xmldata/sexpr2xml-fv-usbmouse.xml
index b9c2aafc2a..ae90e339ec 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-usbmouse.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-usbmouse.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-usbtablet.xml b/tests/sexpr2xmldata/sexpr2xml-fv-usbtablet.xml
index 44a08678a4..f81c47a6e9 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-usbtablet.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-usbtablet.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-utc.xml b/tests/sexpr2xmldata/sexpr2xml-fv-utc.xml
index 584fbfbffb..c783d930b1 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-utc.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-utc.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv-v2.xml b/tests/sexpr2xmldata/sexpr2xml-fv-v2.xml
index f910412171..bd3b107d2b 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv-v2.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv-v2.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-fv.xml b/tests/sexpr2xmldata/sexpr2xml-fv.xml
index 584fbfbffb..c783d930b1 100644
--- a/tests/sexpr2xmldata/sexpr2xml-fv.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-fv.xml
@@ -21,11 +21,13 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/foo.img'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
       <driver name='file'/>
       <source file='/root/boot.iso'/>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-net-bridged.xml b/tests/sexpr2xmldata/sexpr2xml-net-bridged.xml
index da403bddb9..ce7954ddea 100644
--- a/tests/sexpr2xmldata/sexpr2xml-net-bridged.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-net-bridged.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <interface type='bridge'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-net-e1000.xml b/tests/sexpr2xmldata/sexpr2xml-net-e1000.xml
index 1ce70671c6..286209bee3 100644
--- a/tests/sexpr2xmldata/sexpr2xml-net-e1000.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-net-e1000.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <interface type='bridge'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-net-routed.xml b/tests/sexpr2xmldata/sexpr2xml-net-routed.xml
index 3a31f5f254..0ab3b6dd07 100644
--- a/tests/sexpr2xmldata/sexpr2xml-net-routed.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-net-routed.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <interface type='ethernet'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-no-source-cdrom.xml b/tests/sexpr2xmldata/sexpr2xml-no-source-cdrom.xml
index 055b0d3d7e..00d18ce52f 100644
--- a/tests/sexpr2xmldata/sexpr2xml-no-source-cdrom.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-no-source-cdrom.xml
@@ -23,9 +23,11 @@
     <disk type='block' device='disk'>
       <driver name='phy'/>
       <source dev='/dev/sda8'/>
+      <backingStore/>
       <target dev='hda' bus='ide'/>
     </disk>
     <disk type='file' device='cdrom'>
+      <backingStore/>
       <target dev='hdc' bus='ide'/>
       <readonly/>
     </disk>
diff --git a/tests/sexpr2xmldata/sexpr2xml-pci-devs.xml b/tests/sexpr2xmldata/sexpr2xml-pci-devs.xml
index 146b77954c..a404484b18 100644
--- a/tests/sexpr2xmldata/sexpr2xml-pci-devs.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-pci-devs.xml
@@ -18,6 +18,7 @@
     <disk type='block' device='disk'>
       <driver name='phy'/>
       <source dev='/dev/MainVG/GuestVG'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-pv-bootloader-cmdline.xml b/tests/sexpr2xmldata/sexpr2xml-pv-bootloader-cmdline.xml
index f0e34f72eb..0e92d0e95a 100644
--- a/tests/sexpr2xmldata/sexpr2xml-pv-bootloader-cmdline.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-pv-bootloader-cmdline.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-pv-bootloader.xml b/tests/sexpr2xmldata/sexpr2xml-pv-bootloader.xml
index 80efe82d46..bafe97fc87 100644
--- a/tests/sexpr2xmldata/sexpr2xml-pv-bootloader.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-pv-bootloader.xml
@@ -17,6 +17,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-pv-localtime.xml b/tests/sexpr2xmldata/sexpr2xml-pv-localtime.xml
index 348049a0e8..fc57fa938d 100644
--- a/tests/sexpr2xmldata/sexpr2xml-pv-localtime.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-pv-localtime.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-pv-vcpus.xml b/tests/sexpr2xmldata/sexpr2xml-pv-vcpus.xml
index 6f7cffccb6..a55f83e6f1 100644
--- a/tests/sexpr2xmldata/sexpr2xml-pv-vcpus.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-pv-vcpus.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-pv-vfb-new-vncdisplay.xml b/tests/sexpr2xmldata/sexpr2xml-pv-vfb-new-vncdisplay.xml
index e8c3cdab4e..9ae7bff674 100644
--- a/tests/sexpr2xmldata/sexpr2xml-pv-vfb-new-vncdisplay.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-pv-vfb-new-vncdisplay.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-pv-vfb-new.xml b/tests/sexpr2xmldata/sexpr2xml-pv-vfb-new.xml
index 365d3c9ffe..c2eb798b5a 100644
--- a/tests/sexpr2xmldata/sexpr2xml-pv-vfb-new.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-pv-vfb-new.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-pv-vfb-orig.xml b/tests/sexpr2xmldata/sexpr2xml-pv-vfb-orig.xml
index 365d3c9ffe..c2eb798b5a 100644
--- a/tests/sexpr2xmldata/sexpr2xml-pv-vfb-orig.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-pv-vfb-orig.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-pv-vfb-type-crash.xml b/tests/sexpr2xmldata/sexpr2xml-pv-vfb-type-crash.xml
index 5333292ce7..0fee41ceda 100644
--- a/tests/sexpr2xmldata/sexpr2xml-pv-vfb-type-crash.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-pv-vfb-type-crash.xml
@@ -17,6 +17,7 @@
     <disk type='block' device='disk'>
       <driver name='phy'/>
       <source dev='/dev/vg_dom0test/test2vm'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <interface type='bridge'>
diff --git a/tests/sexpr2xmldata/sexpr2xml-pv.xml b/tests/sexpr2xmldata/sexpr2xml-pv.xml
index 7496539478..36b8c1eb6b 100644
--- a/tests/sexpr2xmldata/sexpr2xml-pv.xml
+++ b/tests/sexpr2xmldata/sexpr2xml-pv.xml
@@ -18,6 +18,7 @@
     <disk type='file' device='disk'>
       <driver name='file'/>
       <source file='/root/some.img'/>
+      <backingStore/>
       <target dev='xvda' bus='xen'/>
     </disk>
     <console type='pty'>
-- 
2.39.5