diff -r 2980edcf1264 -r c0639bb5beaa src/python/m5/simulate.py
--- a/src/python/m5/simulate.py	Wed Oct 24 18:08:40 2012 -0400
+++ b/src/python/m5/simulate.py	Wed Oct 24 18:10:48 2012 -0400
@@ -181,6 +181,14 @@
     while (not all_drained):
         all_drained = _drain()
 
+def memWriteback(root):
+    for obj in root.descendants():
+        obj.memWriteback()
+
+def memInvalidate(root):
+    for obj in root.descendants():
+        obj.memInvalidate()
+
 def resume(root):
     for obj in root.descendants(): obj.drainResume()
 
@@ -189,6 +197,7 @@
     if not isinstance(root, objects.Root):
         raise TypeError, "Checkpoint must be called on a root object."
     drain(root)
+    memWriteback(root)
     print "Writing checkpoint"
     internal.core.serializeAll(dir)
     resume(root)
diff -r 2980edcf1264 -r c0639bb5beaa src/sim/drain.hh
--- a/src/sim/drain.hh	Wed Oct 24 18:08:40 2012 -0400
+++ b/src/sim/drain.hh	Wed Oct 24 18:10:48 2012 -0400
@@ -202,6 +202,29 @@
      */
     virtual void drainResume();
 
+    /**
+     * Write back dirty buffers to memory using functional writes.
+     *
+     * After returning, an object implementing this method should have
+     * written all its dirty data back to memory. This method is
+     * typically used to prepare a system with caches for
+     * checkpointing.
+     */
+    virtual void memWriteback() {};
+
+    /**
+     * Invalidate the contents of memory buffers.
+     *
+     * When the switching to hardware virtualized CPU models, we need
+     * to make sure that we don't have any cached state in the system
+     * that might become stale when we return. This method is used to
+     * flush all such state back to main memory.
+     *
+     * @warn This does <i>not</i> cause any dirty state to be written
+     * back to memory.
+     */
+    virtual void memInvalidate() {};
+
     State getDrainState() const { return _drainState; }
 
   protected: