qerror: Add QERR_UNKNOWN_BLOCK_FORMAT_FEATURE

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com>
(cherry picked from commit f54e3641)

qerror.c

@@ -200,6 +200,11 @@ static const QErrorStringTable qerror_table[] = {
         .error_fmt = QERR_UNDEFINED_ERROR,
         .desc      = "An undefined error has ocurred",
     },
+    {
+        .error_fmt = QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
+        .desc      = "'%(device)' uses a %(format) feature which is not "
+                     "supported by this qemu version: %(feature)",
+    },
     {
         .error_fmt = QERR_VNC_SERVER_FAILED,
         .desc      = "Could not start VNC server on %(target)",

qerror.h

@@ -165,6 +165,9 @@ QError *qobject_to_qerror(const QObject *obj);
 #define QERR_UNDEFINED_ERROR \
     "{ 'class': 'UndefinedError', 'data': {} }"
 
+#define QERR_UNKNOWN_BLOCK_FORMAT_FEATURE \
+    "{ 'class': 'UnknownBlockFormatFeature', 'data': { 'device': %s, 'format': %s, 'feature': %s } }"
+
 #define QERR_VNC_SERVER_FAILED \
     "{ 'class': 'VNCServerFailed', 'data': { 'target': %s } }"