diff --git a/tests/qemublocktest.c b/tests/qemublocktest.c
index f8ecbcc3d8..b15d90b614 100644
--- a/tests/qemublocktest.c
+++ b/tests/qemublocktest.c
@@ -466,6 +466,11 @@ mymain(void)
     TEST_DISK_TO_JSON("file-qcow2-backing-chain-encryption");
     TEST_DISK_TO_JSON("network-qcow2-backing-chain-encryption_auth");
 
+    TEST_DISK_TO_JSON("file-backing_basic-unmap");
+    TEST_DISK_TO_JSON("file-backing_basic-unmap-detect");
+    TEST_DISK_TO_JSON("file-backing_basic-unmap-ignore");
+    TEST_DISK_TO_JSON("file-backing_basic-detect");
+
  cleanup:
     virHashFree(diskxmljsondata.schema);
     qemuTestDriverFree(&driver);
diff --git a/tests/qemublocktestdata/xml2json/file-backing_basic-detect.json b/tests/qemublocktestdata/xml2json/file-backing_basic-detect.json
new file mode 100644
index 0000000000..c1e4c40757
--- /dev/null
+++ b/tests/qemublocktestdata/xml2json/file-backing_basic-detect.json
@@ -0,0 +1,60 @@
+{
+  "node-name": "node-a-f",
+  "read-only": false,
+  "detect-zeroes": "on",
+  "driver": "qcow",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/a",
+    "node-name": "node-a-s",
+    "read-only": false,
+    "discard": "unmap"
+  },
+  "backing": "node-b-f"
+}
+{
+  "node-name": "node-b-f",
+  "read-only": true,
+  "driver": "qed",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/b",
+    "node-name": "node-b-s",
+    "read-only": true,
+    "discard": "unmap"
+  },
+  "backing": "node-c-f"
+}
+{
+  "node-name": "node-c-f",
+  "read-only": true,
+  "driver": "vmdk",
+  "file": {
+    "driver": "gluster",
+    "volume": "images",
+    "path": "c",
+    "server": [
+      {
+        "type": "inet",
+        "host": "test.org",
+        "port": "24007"
+      }
+    ],
+    "node-name": "node-c-s",
+    "read-only": true,
+    "discard": "unmap"
+  },
+  "backing": "node-d-f"
+}
+{
+  "node-name": "node-d-f",
+  "read-only": true,
+  "driver": "raw",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/d",
+    "node-name": "node-d-s",
+    "read-only": true,
+    "discard": "unmap"
+  }
+}
diff --git a/tests/qemublocktestdata/xml2json/file-backing_basic-detect.xml b/tests/qemublocktestdata/xml2json/file-backing_basic-detect.xml
new file mode 100644
index 0000000000..eaf89d316a
--- /dev/null
+++ b/tests/qemublocktestdata/xml2json/file-backing_basic-detect.xml
@@ -0,0 +1,47 @@
+<disk type='file' device='disk'>
+  <driver name='qemu' type='qcow' detect_zeroes='unmap'/>
+  <source file='/var/lib/libvirt/images/a'>
+    <privateData>
+      <nodenames>
+        <nodename type='storage' name='node-a-s'/>
+        <nodename type='format' name='node-a-f'/>
+      </nodenames>
+    </privateData>
+  </source>
+  <backingStore type='file' index='1'>
+    <format type='qed'/>
+    <source file='/var/lib/libvirt/images/b'>
+      <privateData>
+        <nodenames>
+          <nodename type='storage' name='node-b-s'/>
+          <nodename type='format' name='node-b-f'/>
+        </nodenames>
+      </privateData>
+    </source>
+    <backingStore type='network' index='2'>
+      <format type='vmdk'/>
+      <source protocol='gluster' name='images/c'>
+        <host name='test.org'/>
+        <privateData>
+          <nodenames>
+            <nodename type='storage' name='node-c-s'/>
+            <nodename type='format' name='node-c-f'/>
+          </nodenames>
+        </privateData>
+      </source>
+      <backingStore type='file' index='3'>
+        <format type='raw'/>
+        <source file='/var/lib/libvirt/images/d'>
+          <privateData>
+            <nodenames>
+              <nodename type='storage' name='node-d-s'/>
+              <nodename type='format' name='node-d-f'/>
+            </nodenames>
+          </privateData>
+        </source>
+        <backingStore/>
+      </backingStore>
+    </backingStore>
+  </backingStore>
+  <target dev='vda'/>
+</disk>
diff --git a/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-detect.json b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-detect.json
new file mode 100644
index 0000000000..b00008dd54
--- /dev/null
+++ b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-detect.json
@@ -0,0 +1,64 @@
+{
+  "node-name": "node-a-f",
+  "read-only": false,
+  "discard": "unmap",
+  "detect-zeroes": "unmap",
+  "driver": "qcow",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/a",
+    "node-name": "node-a-s",
+    "read-only": false,
+    "discard": "unmap"
+  },
+  "backing": "node-b-f"
+}
+{
+  "node-name": "node-b-f",
+  "read-only": true,
+  "discard": "unmap",
+  "driver": "qed",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/b",
+    "node-name": "node-b-s",
+    "read-only": true,
+    "discard": "unmap"
+  },
+  "backing": "node-c-f"
+}
+{
+  "node-name": "node-c-f",
+  "read-only": true,
+  "discard": "unmap",
+  "driver": "vmdk",
+  "file": {
+    "driver": "gluster",
+    "volume": "images",
+    "path": "c",
+    "server": [
+      {
+        "type": "inet",
+        "host": "test.org",
+        "port": "24007"
+      }
+    ],
+    "node-name": "node-c-s",
+    "read-only": true,
+    "discard": "unmap"
+  },
+  "backing": "node-d-f"
+}
+{
+  "node-name": "node-d-f",
+  "read-only": true,
+  "discard": "unmap",
+  "driver": "raw",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/d",
+    "node-name": "node-d-s",
+    "read-only": true,
+    "discard": "unmap"
+  }
+}
diff --git a/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-detect.xml b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-detect.xml
new file mode 100644
index 0000000000..4638a78541
--- /dev/null
+++ b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-detect.xml
@@ -0,0 +1,47 @@
+<disk type='file' device='disk'>
+  <driver name='qemu' type='qcow' discard='unmap' detect_zeroes='unmap'/>
+  <source file='/var/lib/libvirt/images/a'>
+    <privateData>
+      <nodenames>
+        <nodename type='storage' name='node-a-s'/>
+        <nodename type='format' name='node-a-f'/>
+      </nodenames>
+    </privateData>
+  </source>
+  <backingStore type='file' index='1'>
+    <format type='qed'/>
+    <source file='/var/lib/libvirt/images/b'>
+      <privateData>
+        <nodenames>
+          <nodename type='storage' name='node-b-s'/>
+          <nodename type='format' name='node-b-f'/>
+        </nodenames>
+      </privateData>
+    </source>
+    <backingStore type='network' index='2'>
+      <format type='vmdk'/>
+      <source protocol='gluster' name='images/c'>
+        <host name='test.org'/>
+        <privateData>
+          <nodenames>
+            <nodename type='storage' name='node-c-s'/>
+            <nodename type='format' name='node-c-f'/>
+          </nodenames>
+        </privateData>
+      </source>
+      <backingStore type='file' index='3'>
+        <format type='raw'/>
+        <source file='/var/lib/libvirt/images/d'>
+          <privateData>
+            <nodenames>
+              <nodename type='storage' name='node-d-s'/>
+              <nodename type='format' name='node-d-f'/>
+            </nodenames>
+          </privateData>
+        </source>
+        <backingStore/>
+      </backingStore>
+    </backingStore>
+  </backingStore>
+  <target dev='vda'/>
+</disk>
diff --git a/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-ignore.json b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-ignore.json
new file mode 100644
index 0000000000..5419deafc0
--- /dev/null
+++ b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-ignore.json
@@ -0,0 +1,64 @@
+{
+  "node-name": "node-a-f",
+  "read-only": false,
+  "discard": "ignore",
+  "detect-zeroes": "on",
+  "driver": "qcow",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/a",
+    "node-name": "node-a-s",
+    "read-only": false,
+    "discard": "unmap"
+  },
+  "backing": "node-b-f"
+}
+{
+  "node-name": "node-b-f",
+  "read-only": true,
+  "discard": "ignore",
+  "driver": "qed",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/b",
+    "node-name": "node-b-s",
+    "read-only": true,
+    "discard": "unmap"
+  },
+  "backing": "node-c-f"
+}
+{
+  "node-name": "node-c-f",
+  "read-only": true,
+  "discard": "ignore",
+  "driver": "vmdk",
+  "file": {
+    "driver": "gluster",
+    "volume": "images",
+    "path": "c",
+    "server": [
+      {
+        "type": "inet",
+        "host": "test.org",
+        "port": "24007"
+      }
+    ],
+    "node-name": "node-c-s",
+    "read-only": true,
+    "discard": "unmap"
+  },
+  "backing": "node-d-f"
+}
+{
+  "node-name": "node-d-f",
+  "read-only": true,
+  "discard": "ignore",
+  "driver": "raw",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/d",
+    "node-name": "node-d-s",
+    "read-only": true,
+    "discard": "unmap"
+  }
+}
diff --git a/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-ignore.xml b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-ignore.xml
new file mode 100644
index 0000000000..b2d599fc6c
--- /dev/null
+++ b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap-ignore.xml
@@ -0,0 +1,47 @@
+<disk type='file' device='disk'>
+  <driver name='qemu' type='qcow' discard='ignore' detect_zeroes='on'/>
+  <source file='/var/lib/libvirt/images/a'>
+    <privateData>
+      <nodenames>
+        <nodename type='storage' name='node-a-s'/>
+        <nodename type='format' name='node-a-f'/>
+      </nodenames>
+    </privateData>
+  </source>
+  <backingStore type='file' index='1'>
+    <format type='qed'/>
+    <source file='/var/lib/libvirt/images/b'>
+      <privateData>
+        <nodenames>
+          <nodename type='storage' name='node-b-s'/>
+          <nodename type='format' name='node-b-f'/>
+        </nodenames>
+      </privateData>
+    </source>
+    <backingStore type='network' index='2'>
+      <format type='vmdk'/>
+      <source protocol='gluster' name='images/c'>
+        <host name='test.org'/>
+        <privateData>
+          <nodenames>
+            <nodename type='storage' name='node-c-s'/>
+            <nodename type='format' name='node-c-f'/>
+          </nodenames>
+        </privateData>
+      </source>
+      <backingStore type='file' index='3'>
+        <format type='raw'/>
+        <source file='/var/lib/libvirt/images/d'>
+          <privateData>
+            <nodenames>
+              <nodename type='storage' name='node-d-s'/>
+              <nodename type='format' name='node-d-f'/>
+            </nodenames>
+          </privateData>
+        </source>
+        <backingStore/>
+      </backingStore>
+    </backingStore>
+  </backingStore>
+  <target dev='vda'/>
+</disk>
diff --git a/tests/qemublocktestdata/xml2json/file-backing_basic-unmap.json b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap.json
new file mode 100644
index 0000000000..1efc462c06
--- /dev/null
+++ b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap.json
@@ -0,0 +1,63 @@
+{
+  "node-name": "node-a-f",
+  "read-only": false,
+  "discard": "unmap",
+  "driver": "qcow",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/a",
+    "node-name": "node-a-s",
+    "read-only": false,
+    "discard": "unmap"
+  },
+  "backing": "node-b-f"
+}
+{
+  "node-name": "node-b-f",
+  "read-only": true,
+  "discard": "unmap",
+  "driver": "qed",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/b",
+    "node-name": "node-b-s",
+    "read-only": true,
+    "discard": "unmap"
+  },
+  "backing": "node-c-f"
+}
+{
+  "node-name": "node-c-f",
+  "read-only": true,
+  "discard": "unmap",
+  "driver": "vmdk",
+  "file": {
+    "driver": "gluster",
+    "volume": "images",
+    "path": "c",
+    "server": [
+      {
+        "type": "inet",
+        "host": "test.org",
+        "port": "24007"
+      }
+    ],
+    "node-name": "node-c-s",
+    "read-only": true,
+    "discard": "unmap"
+  },
+  "backing": "node-d-f"
+}
+{
+  "node-name": "node-d-f",
+  "read-only": true,
+  "discard": "unmap",
+  "driver": "raw",
+  "file": {
+    "driver": "file",
+    "filename": "/var/lib/libvirt/images/d",
+    "node-name": "node-d-s",
+    "read-only": true,
+    "discard": "unmap"
+  }
+}
diff --git a/tests/qemublocktestdata/xml2json/file-backing_basic-unmap.xml b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap.xml
new file mode 100644
index 0000000000..68484991c1
--- /dev/null
+++ b/tests/qemublocktestdata/xml2json/file-backing_basic-unmap.xml
@@ -0,0 +1,47 @@
+<disk type='file' device='disk'>
+  <driver name='qemu' type='qcow' discard='unmap'/>
+  <source file='/var/lib/libvirt/images/a'>
+    <privateData>
+      <nodenames>
+        <nodename type='storage' name='node-a-s'/>
+        <nodename type='format' name='node-a-f'/>
+      </nodenames>
+    </privateData>
+  </source>
+  <backingStore type='file' index='1'>
+    <format type='qed'/>
+    <source file='/var/lib/libvirt/images/b'>
+      <privateData>
+        <nodenames>
+          <nodename type='storage' name='node-b-s'/>
+          <nodename type='format' name='node-b-f'/>
+        </nodenames>
+      </privateData>
+    </source>
+    <backingStore type='network' index='2'>
+      <format type='vmdk'/>
+      <source protocol='gluster' name='images/c'>
+        <host name='test.org'/>
+        <privateData>
+          <nodenames>
+            <nodename type='storage' name='node-c-s'/>
+            <nodename type='format' name='node-c-f'/>
+          </nodenames>
+        </privateData>
+      </source>
+      <backingStore type='file' index='3'>
+        <format type='raw'/>
+        <source file='/var/lib/libvirt/images/d'>
+          <privateData>
+            <nodenames>
+              <nodename type='storage' name='node-d-s'/>
+              <nodename type='format' name='node-d-f'/>
+            </nodenames>
+          </privateData>
+        </source>
+        <backingStore/>
+      </backingStore>
+    </backingStore>
+  </backingStore>
+  <target dev='vda'/>
+</disk>