x86: add tlb checkpointing

This patch adds checkpointing support to x86 tlb. It upgrades the
cpt_upgrader.py script so that previously created checkpoints can
be updated. It moves the checkpoint version to 6.

1 files changed, 31 insertions, 0 deletions

diff --git a/src/arch/x86/tlb.cc b/src/arch/x86/tlb.cc
index 52cc3e0ee..087cfbadf 100644
--- a/src/arch/x86/tlb.cc
+++ b/src/arch/x86/tlb.cc
@@ -439,11 +439,42 @@ TLB::getWalker()
 void
 TLB::serialize(std::ostream &os)
 {
+    // Only store the entries in use.
+    uint32_t _size = size - freeList.size();
+    SERIALIZE_SCALAR(_size);
+    SERIALIZE_SCALAR(lruSeq);
+
+    uint32_t _count = 0;
+
+    for (uint32_t x = 0; x < size; x++) {
+        if (tlb[x].trieHandle != NULL) {
+            os << "\n[" << csprintf("%s.Entry%d", name(), _count) << "]\n";
+            tlb[x].serialize(os);
+            _count++;
+        }
+    }
 }
 
 void
 TLB::unserialize(Checkpoint *cp, const std::string &section)
 {
+    // Do not allow to restore with a smaller tlb.
+    uint32_t _size;
+    UNSERIALIZE_SCALAR(_size);
+    if (_size > size) {
+        fatal("TLB size less than the one in checkpoint!");
+    }
+
+    UNSERIALIZE_SCALAR(lruSeq);
+
+    for (uint32_t x = 0; x < _size; x++) {
+        TlbEntry *newEntry = freeList.front();
+        freeList.pop_front();
+
+        newEntry->unserialize(cp, csprintf("%s.Entry%d", name(), x));
+        newEntry->trieHandle = trie.insert(newEntry->vaddr,
+            TlbEntryTrie::MaxBits - newEntry->logBytes, newEntry);
+    }
 }
 
 BaseMasterPort *