tools/migration: Drop IHDR_VERSION constant from libxc and python

Migration v3 is in the process of being introduced, meaning that the code has
to cope with both versions.  Use an explicit 2 for now.

For the verify-stream-v2 and convert-legacy-stream scripts, update text to say
"v2 (or later)".  What matters is the distinction vs legacy streams.

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

tools/python/scripts/convert-legacy-stream

@@ -79,7 +79,7 @@ def write_libxc_ihdr():
     stream_write(pack(libxc.IHDR_FORMAT,
                       libxc.IHDR_MARKER,  # Marker
                       libxc.IHDR_IDENT,   # Ident
-                      libxc.IHDR_VERSION, # Version
+                      2,                  # Version
                       libxc.IHDR_OPT_LE,  # Options
                       0, 0))              # Reserved
 
@@ -632,13 +632,13 @@ def main():
                           usage = ("%prog [options] -i INPUT -o OUTPUT"
                                    " -w WIDTH -g GUEST"),
                           description =
-                          "Convert a legacy stream to a v2 stream")
+                          "Convert a legacy stream to a v2 (or later) stream")
 
     # Required options
     parser.add_option("-i", "--in", dest = "fin", metavar = "<FD or FILE>",
                       help = "Legacy input to convert")
     parser.add_option("-o", "--out", dest = "fout", metavar = "<FD or FILE>",
-                      help = "v2 format output")
+                      help = "v2 (or later) format output")
     parser.add_option("-w", "--width", dest = "twidth",
                       metavar = "<32/64>", choices = ["32", "64"],
                       help = "Legacy toolstack bitness")

tools/python/scripts/verify-stream-v2

@@ -108,7 +108,7 @@ def main():
 
     parser = OptionParser(usage = "%prog [options]",
                           description =
-                          "Verify a stream according to the v2 spec")
+                          "Verify a stream according to the v2 (or later) spec")
 
     # Optional options
     parser.add_option("-i", "--in", dest = "fin", metavar = "<FD or FILE>",

tools/python/xen/migration/libxc.py

@@ -19,7 +19,6 @@ IHDR_FORMAT = "!QIIHHI"
 
 IHDR_MARKER  = 0xffffffffffffffff
 IHDR_IDENT   = 0x58454E46 # "XENF" in ASCII
-IHDR_VERSION = 2
 
 IHDR_OPT_BIT_ENDIAN = 0
 IHDR_OPT_LE = (0 << IHDR_OPT_BIT_ENDIAN)
@@ -113,7 +112,7 @@ HVM_PARAMS_ENTRY_FORMAT   = "QQ"
 HVM_PARAMS_FORMAT         = "II"
 
 class VerifyLibxc(VerifyBase):
-    """ Verify a Libxc v2 stream """
+    """ Verify a Libxc v2 (or later) stream """
 
     def __init__(self, info, read):
         VerifyBase.__init__(self, info, read)
@@ -144,9 +143,9 @@ class VerifyLibxc(VerifyBase):
             raise StreamError("Bad image id: Expected 0x%x, got 0x%x" %
                               (IHDR_IDENT, ident))
 
-        if version != IHDR_VERSION:
-            raise StreamError("Unknown image version: Expected %d, got %d" %
-                              (IHDR_VERSION, version))
+        if version != 2:
+            raise StreamError("Unknown image version: Expected 2, got %d" %
+                              (version, ))
 
         if options & IHDR_OPT_RESZ_MASK:
             raise StreamError("Reserved bits set in image options field: 0x%x" %