[Qemu-devel] [PATCH 6/6] python script for extracting bitmap from a binary file

[Sanidhya Kashyap <sanidhya.iiith@gmail.com>]

This script extracts the bitmap only from a binary file. It takes only
a single input as file. This will be useful to users for exploring the
writable working set for the VM.

Signed-off-by: Sanidhya Kashyap <sanidhya.iiith@gmail.com>
---
 scripts/extract-bitmap.py | 68 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100755 scripts/extract-bitmap.py

diff --git a/scripts/extract-bitmap.py b/scripts/extract-bitmap.py
new file mode 100755
index 0000000..64ce136
--- /dev/null
+++ b/scripts/extract-bitmap.py
@@ -0,0 +1,68 @@
+#!/usr/bin/python
+# This python script helps in extracting the dirty bitmap present
+# in the file after executing the log-dirty-bitmap command either
+# from the qmp or hmp interface. This file only processes binary
+# file obtained via command.
+#
+# Copyright (C) Sanidhya Kashyap <sanidhya.iiith@gmail.com>
+#
+# Authors:
+#       Sanidhya Kashyap
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, see <http://www.gnu.org/licenses/>.
+#
+
+import struct
+import argparse
+from functools import partial
+
+long_bytes = 8
+complete_bitmap_list = []
+
+def get_unsigned_long_integer(value):
+    return struct.unpack('<Q', value)[0]
+
+def get_long_integer(value):
+    return struct.unpack('<q',value)[0]
+
+def dump_bitmap(infile, bitmap_length):
+    count = 1
+    bitmap_list = []
+    for value in iter(partial(infile.read, long_bytes), ''):
+        if (count % bitmap_length):
+            count += 1
+            bitmap_list.append(hex(get_unsigned_long_integer(value)))
+        else:
+            complete_bitmap_list.append(bitmap_list)
+            count = 1
+            bitmap_list = []
+    # currently, the complete list is printed. It is up to the user to decide about
+    # the usage of the bitmap as the bitmap provides the writable working set of the
+    # VM for a particular duration.
+    print complete_bitmap_list
+
+def main():
+    extracter = argparse.ArgumentParser(description='Extract dirty bitmap from binary file.')
+    extracter.add_argument('infile', help='Input file to extract the bitmap')
+    args = extracter.parse_args()
+    print 'The filename is {}'.format(args.infile)
+
+    infile = open(format(args.infile), 'rb')
+
+    ram_bitmap_pages = get_long_integer(infile.read(long_bytes))
+    print ram_bitmap_pages
+    bitmap_length = get_long_integer(infile.read(long_bytes))
+    print bitmap_length
+
+    dump_bitmap(infile, bitmap_length);
+
+    infile.close()
+
+if __name__ == '__main__':
+    main()
-- 
1.8.3.1