python/migration: Update validation logic to understand a v3 stream

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

tools/python/xen/migration/libxc.py

@@ -119,6 +119,7 @@ class VerifyLibxc(VerifyBase):
     def __init__(self, info, read):
         VerifyBase.__init__(self, info, read)
 
+        self.version = 0
         self.squashed_pagedata_records = 0
 
 
@@ -145,9 +146,12 @@ class VerifyLibxc(VerifyBase):
             raise StreamError("Bad image id: Expected 0x%x, got 0x%x" %
                               (IHDR_IDENT, ident))
 
-        if version != 2:
-            raise StreamError("Unknown image version: Expected 2, got %d" %
-                              (version, ))
+        if not (2 <= version <= 3):
+            raise StreamError(
+                "Unknown image version: Expected 2 <= ver <= 3, got %d" %
+                (version, ))
+
+        self.version = version
 
         if options & IHDR_OPT_RESZ_MASK:
             raise StreamError("Reserved bits set in image options field: 0x%x" %
@@ -164,7 +168,8 @@ class VerifyLibxc(VerifyBase):
                 "Stream is not native endianess - unable to validate")
 
         endian = ["little", "big"][options & IHDR_OPT_LE]
-        self.info("Libxc Image Header: %s endian" % (endian, ))
+        self.info("Libxc Image Header: Version %d, %s endian" %
+                  (version, endian))
 
 
     def verify_dhdr(self):
@@ -424,6 +429,16 @@ class VerifyLibxc(VerifyBase):
         raise RecordError("Found checkpoint dirty pfn list record in stream")
 
 
+    def verify_record_static_data_end(self, content):
+        """ static data end record """
+
+        if len(content) != 0:
+            raise RecordError("End record with non-zero length")
+
+        if self.version < 3:
+            raise RecordError("Static data end record found in v2 stream")
+
+
 record_verifiers = {
     REC_TYPE_end:
         VerifyLibxc.verify_record_end,
@@ -465,4 +480,7 @@ record_verifiers = {
         VerifyLibxc.verify_record_checkpoint,
     REC_TYPE_checkpoint_dirty_pfn_list:
         VerifyLibxc.verify_record_checkpoint_dirty_pfn_list,
+
+    REC_TYPE_static_data_end:
+        VerifyLibxc.verify_record_static_data_end,
     }