sim: Provide a framework for detecting out of data checkpoints and migrating them.

src/SConscript

@@ -354,6 +354,7 @@ def makeTheISA(source, target, env):
 
 #define THE_ISA ${{define(target_isa)}}
 #define TheISA ${{namespace(target_isa)}}
+#define THE_ISA_STR "${{target_isa}}"
 
 #endif // __CONFIG_THE_ISA_HH__''')
 

src/sim/root.cc

@@ -32,6 +32,7 @@
  */
 
 #include "base/misc.hh"
+#include "config/the_isa.hh"
 #include "debug/TimeSync.hh"
 #include "sim/full_system.hh"
 #include "sim/root.hh"
@@ -121,9 +122,45 @@ Root::initState()
 void
 Root::loadState(Checkpoint *cp)
 {
+    SimObject::loadState(cp);
     timeSyncEnable(params()->time_sync_enable);
 }
 
+void
+Root::serialize(std::ostream &os)
+{
+    uint64_t cpt_ver = gem5CheckpointVersion;
+    SERIALIZE_SCALAR(cpt_ver);
+    SERIALIZE_SCALAR(FullSystem);
+    std::string isa = THE_ISA_STR;
+    SERIALIZE_SCALAR(isa);
+}
+
+void
+Root::unserialize(Checkpoint *cp, const std::string &section)
+{
+    uint64_t cpt_ver = 0;
+    UNSERIALIZE_OPT_SCALAR(cpt_ver);
+    if (cpt_ver < gem5CheckpointVersion) {
+        warn("**********************************************************\n");
+        warn("!!!! Checkpoint ver %#x is older than current ver %#x !!!!\n",
+                cpt_ver, gem5CheckpointVersion);
+        warn("You might experience some issues when restoring and should run "
+             "the checkpoint upgrader (util/cpt_upgrade.py) on your "
+             "checkpoint\n");
+        warn("**********************************************************\n");
+    } else if (cpt_ver > gem5CheckpointVersion) {
+        warn("**********************************************************\n");
+        warn("!!!! Checkpoint ver %#x is newer than current ver %#x !!!!\n",
+                cpt_ver, gem5CheckpointVersion);
+        warn("Running a new checkpoint with an older version of gem5 is not "
+             "supported. While it might work, you may experience incorrect "
+             "behavior or crashes.\n");
+        warn("**********************************************************\n");
+     }
+}
+
+
 bool FullSystem;
 unsigned int FullSystemInt;
 

src/sim/root.hh

@@ -111,6 +111,10 @@ class Root : public SimObject
     /** Schedule the timesync event at initState() when not unserializing
      */
     void initState();
+
+    virtual void serialize(std::ostream &os);
+    virtual void unserialize(Checkpoint *cp, const std::string &section);
+
 };
 
 #endif // __SIM_ROOT_HH__

src/sim/serialize.hh

@@ -50,6 +50,15 @@ class Serializable;
 class Checkpoint;
 class SimObject;
 
+/** The current version of the checkpoint format.
+ * This should be incremented by 1 and only 1 for every new version, where a new
+ * version is defined as a checkpoint created before this version wont work on
+ * the current version until the checkpoint format is updated. Adding a new
+ * SimObject shouldn't cause the version number to increase, only changes to
+ * existing objects such as serializing/unserializing more stote, changing sizes
+ * of serialized arrays, etc. */
+static const uint64_t gem5CheckpointVersion = 0x0000000000000001;
+
 template <class T>
 void paramOut(std::ostream &os, const std::string &name, const T &param);
 

util/cpt_upgrader.py

@@ -0,0 +1,167 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2012 ARM Limited
+# All rights reserved
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Ali Saidi
+#
+
+import ConfigParser
+import sys, os
+import os.path as osp
+
+def from_0(cpt):
+    pass
+
+# An example of a translator
+def from_1(cpt):
+    if cpt.get('root','isa') == 'arm':
+        for sec in cpt.sections():
+            import re
+            # Search for all the execution contexts
+            if re.search('.*sys.*\.cpu.*\.x.\..*', sec):
+                # Update each one
+                mr = cpt.get(sec, 'miscRegs').split()
+                #mr.insert(21,0)
+                #mr.insert(26,0)
+                cpt.set(sec, 'miscRegs', ' '.join(str(x) for x in mr))
+
+migrations = []
+migrations.append(from_0)
+migrations.append(from_1)
+
+verbose_print = False
+
+def verboseprint(*args):
+    if not verbose_print:
+        return
+    for arg in args:
+        print arg,
+    print
+
+def process_file(path, **kwargs):
+    if not osp.isfile(path):
+        import errno
+        raise IOError(ennro.ENOENT, "No such file", path)
+
+    verboseprint("Processing file %s...." % path)
+
+    if kwargs.get('backup', True):
+        import shutil
+        shutil.copyfile(path, path + '.bak')
+
+    cpt = ConfigParser.SafeConfigParser()
+
+    # gem5 is case sensitive with paramaters
+    cpt.optionxform = str
+
+    # Read the current data
+    cpt_file = file(path, 'r')
+    cpt.readfp(cpt_file)
+    cpt_file.close()
+
+    # Make sure we know what we're starting from
+    if not cpt.has_option('root','cpt_ver'):
+        raise LookupError("cannot determine version of checkpoint")
+
+    cpt_ver = cpt.getint('root','cpt_ver')
+
+    # If the current checkpoint is longer than the migrations list, we have a problem
+    # and someone didn't update this file
+    if cpt_ver > len(migrations):
+        raise ValueError("upgrade script is too old and needs updating")
+
+    verboseprint("\t...file is at version %#x" % cpt_ver)
+
+    if cpt_ver == len(migrations):
+        verboseprint("\t...nothing to do")
+        return
+
+    # Walk through every function from now until the end fixing the checkpoint
+    for v in xrange(cpt_ver,len(migrations)):
+        verboseprint("\t...migrating to version %#x" %  (v + 1))
+        migrations[v](cpt)
+        cpt.set('root','cpt_ver', str(v + 1))
+
+    # Write the old data back
+    verboseprint("\t...completed")
+    cpt.write(file(path, 'w'))
+
+
+if __name__ == '__main__':
+    from optparse import OptionParser
+    parser = OptionParser("usage: %prog [options] <filename or directory>")
+    parser.add_option("-r", "--recurse", action="store_true",
+                      help="Recurse through all subdirectories modifying "\
+                           "each checkpoint that is found")
+    parser.add_option("-N", "--no-backup", action="store_false",
+                      dest="backup", default=True,
+                      help="Do no backup each checkpoint before modifying it")
+    parser.add_option("-v", "--verbose", action="store_true",
+                      help="Print out debugging information as")
+
+    (options, args) = parser.parse_args()
+    if len(args) != 1:
+        parser.error("You must specify a checkpoint file to modify or a "\
+                     "directory of checkpoints to recursively update")
+
+    verbose_print = options.verbose
+
+    # Deal with shell variables and ~
+    path = osp.expandvars(osp.expanduser(args[0]))
+
+    # Process a single file if we have it
+    if osp.isfile(path):
+        process_file(path, **vars(options))
+    # Process an entire directory
+    elif osp.isdir(path):
+        cpt_file = osp.join(path, 'm5.cpt')
+        if options.recurse:
+            # Visit very file and see if it matches
+            for root,dirs,files in os.walk(path):
+                for name in files:
+                    if name == 'm5.cpt':
+                        process_file(osp.join(root,name), **vars(options))
+                for dir in dirs:
+                    pass
+        # Maybe someone passed a cpt.XXXXXXX directory and not m5.cpt
+        elif osp.isfile(cpt_file):
+            process_file(cpt_file, **vars(options))
+        else:
+            print "Error: checkpoint file not found at in %s " % path,
+            print "and recurse not specified"
+            sys.exit(1)
+    sys.exit(0)
+