import invisispec-1.0 source by Mengjia Yan

The original code is at https://github.com/mjyan0720/InvisiSpec-1.0
This code is rebased on upstream gem5 commit 866b200c, which features:
- rdtscp support
- some C++ code optimizations
- newer Linux kernel version number in SE mode

1 files changed, 12 insertions, 1 deletions

diff --git a/src/cpu/o3/inst_queue_impl.hh b/src/cpu/o3/inst_queue_impl.hh
index b34e6d980..980f29b35 100644
--- a/src/cpu/o3/inst_queue_impl.hh
+++ b/src/cpu/o3/inst_queue_impl.hh
@@ -1176,8 +1176,19 @@ InstructionQueue<Impl>::getDeferredMemInstToExecute()
 {
     for (ListIt it = deferredMemInsts.begin(); it != deferredMemInsts.end();
          ++it) {
-        if ((*it)->translationCompleted() || (*it)->isSquashed()) {
+        // [InvisiSpec] we need to check the FenceDelay
+        // a load can be delayed due to
+        // 1. translation delay
+        // 2. virtual fence ahead
+        // 3. not ready to expose and gets a TLB miss
+        // for both (2, 3) we need to restart the translation
+        if ( (*it)->translationCompleted() 
+                || ((*it)->onlyWaitForFence() && !(*it)->fenceDelay())
+                || ((*it)->onlyWaitForExpose() && (*it)->readyToExpose())
+                || (*it)->isSquashed()) {
             DynInstPtr mem_inst = std::move(*it);
+            mem_inst->onlyWaitForFence(false);
+            mem_inst->onlyWaitForExpose(false);
             deferredMemInsts.erase(it);
             return mem_inst;
         }