tests: qemublock: Add cases for creating image overlays on top of disks with <slice>

Add a set of test data to see whether the backing store strings are
formatted reasonably. Note that we don't support direct creation of such
images so those tests are not enabled.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

tests/qemublocktest.c

@@ -1064,6 +1064,8 @@ mymain(void)
     TEST_IMAGE_CREATE("qcow2-backing-raw-nbd", "raw-nbd");
     TEST_IMAGE_CREATE("qcow2-backing-luks", "luks-noopts");
     TEST_IMAGE_CREATE("qcow2-luks-encopts-backing", "qcow2");
+    TEST_IMAGE_CREATE("qcow2-backing-raw-slice", "raw-slice");
+    TEST_IMAGE_CREATE("qcow2-backing-qcow2-slice", "qcow2-slice");
 
     TEST_IMAGE_CREATE("network-gluster-qcow2", NULL);
     TEST_IMAGE_CREATE("network-rbd-qcow2", NULL);

tests/qemublocktestdata/imagecreate/qcow2-backing-qcow2-slice.json

+protocol:
+{
+  "driver": "file",
+  "filename": "/var/lib/libvirt/images/i.qcow2",
+  "size": 4294967296
+}
+
+format:
+{
+  "driver": "qcow2",
+  "file": "0123456789ABCDEF0123456789ABCDE",
+  "size": 8589934590,
+  "backing-file": "json:{\"driver\":\"raw\",\"offset\":1234,\"size\":5768,\"file\":{\"driver\":\"file\",\"filename\":\"/var/lib/libvirt/images/i.qcow2\"}}",
+  "backing-fmt": "qcow2"
+}

tests/qemublocktestdata/imagecreate/qcow2-backing-qcow2-slice.xml

+qcow2.xml
\ No newline at end of file

tests/qemublocktestdata/imagecreate/qcow2-backing-raw-slice.json

+protocol:
+{
+  "driver": "file",
+  "filename": "/var/lib/libvirt/images/i.qcow2",
+  "size": 4294967296
+}
+
+format:
+{
+  "driver": "qcow2",
+  "file": "0123456789ABCDEF0123456789ABCDE",
+  "size": 8589934590,
+  "backing-file": "json:{\"driver\":\"raw\",\"offset\":9876,\"size\":54321,\"file\":{\"driver\":\"file\",\"filename\":\"/var/lib/libvirt/images/i.img\"}}",
+  "backing-fmt": "raw"
+}

tests/qemublocktestdata/imagecreate/qcow2-backing-raw-slice.xml

+qcow2.xml
\ No newline at end of file

tests/qemublocktestdata/imagecreate/qcow2-slice.xml

+<disk device='disk' name='vda'>
+  <driver type='qcow2'/>
+  <source file='/var/lib/libvirt/images/i.qcow2'>
+    <slices>
+      <slice type='storage' offset='1234' size='5768'/>
+    </slices>
+    <privateData>
+      <nodenames>
+        <nodename type='storage' name='0123456789ABCDEF0123456789ABCDE'/>
+        <nodename type='format' name='0123456789ABCDEF0123456789ABCDE'/>
+      </nodenames>
+    </privateData>
+  </source>
+</disk>

tests/qemublocktestdata/imagecreate/raw-slice.xml

+<disk device='disk' name='vda'>
+  <driver type='raw'/>
+  <source file='/var/lib/libvirt/images/i.img'>
+    <slices>
+      <slice type='storage' offset='9876' size='54321'/>
+    </slices>
+    <privateData>
+      <nodenames>
+        <nodename type='storage' name='0123456789ABCDEF0123456789ABCDE'/>
+        <nodename type='format' name='0123456789ABCDEF0123456789ABCDE'/>
+      </nodenames>
+    </privateData>
+  </source>
+</disk>