From 3cd11b02eef1261e0596fc963916d1de2e0c6f69 Mon Sep 17 00:00:00 2001
From: Stanislav Shwartsman <sshwarts@users.sourceforge.net>
Date: Thu, 4 Oct 2012 21:30:50 +0000
Subject: [PATCH] optimization and bugfix for prev commit

---
 bochs/cpu/exception.cc | 51 ++++++++++++++++++------------------------
 bochs/cpu/svm.cc       |  3 +--
 bochs/cpu/vmexit.cc    |  2 --
 bochs/cpu/vmx.cc       |  1 +
 4 files changed, 24 insertions(+), 33 deletions(-)

diff --git a/bochs/cpu/exception.cc b/bochs/cpu/exception.cc
index 78dbe03cd..124e436ef 100644
--- a/bochs/cpu/exception.cc
+++ b/bochs/cpu/exception.cc
@@ -823,7 +823,6 @@ struct BxExceptionInfo exceptions_info[BX_CPU_HANDLED_EXCEPTIONS] = {
 
 // vector:     0..255: vector in IDT
 // error_code: if exception generates and error, push this error code
-// trap:       override exception class to TRAP
 void BX_CPU_C::exception(unsigned vector, Bit16u error_code)
 {
   BX_INSTR_EXCEPTION(BX_CPU_ID, vector, error_code);
@@ -860,34 +859,6 @@ void BX_CPU_C::exception(unsigned vector, Bit16u error_code)
   SvmInterceptException(BX_HARDWARE_EXCEPTION, vector, error_code, push_error);
 #endif
 
-  if (BX_CPU_THIS_PTR last_exception_type == BX_ET_DOUBLE_FAULT) {
-    // restore RIP/RSP to value before error occurred
-    RIP = BX_CPU_THIS_PTR prev_rip;
-    if (BX_CPU_THIS_PTR speculative_rsp)
-      RSP = BX_CPU_THIS_PTR prev_rsp;
-
-    debug(BX_CPU_THIS_PTR prev_rip); // print debug information to the log
-#if BX_SUPPORT_VMX
-    VMexit_TripleFault();
-#endif
-#if BX_DEBUGGER
-    // trap into debugger (similar as done when PANIC occured)
-    bx_debug_break();
-#endif
-    if (SIM->get_param_bool(BXPN_RESET_ON_TRIPLE_FAULT)->get()) {
-      BX_ERROR(("exception(): 3rd (%d) exception with no resolution, shutdown status is %02xh, resetting", vector, DEV_cmos_get_reg(0x0f)));
-      bx_pc_system.Reset(BX_RESET_HARDWARE);
-    }
-    else {
-      BX_PANIC(("exception(): 3rd (%d) exception with no resolution", vector));
-      BX_ERROR(("WARNING: Any simulation after this point is completely bogus !"));
-      shutdown();
-    }
-    longjmp(BX_CPU_THIS_PTR jmp_buf_env, 1); // go back to main decode loop
-  }
-
-  // note: fault-class exceptions _except_ #DB set RF in
-  //       eflags image.
   if (exception_class == BX_EXCEPTION_CLASS_FAULT)
   {
     // restore RIP/RSP to value before error occurred
@@ -895,6 +866,28 @@ void BX_CPU_C::exception(unsigned vector, Bit16u error_code)
     if (BX_CPU_THIS_PTR speculative_rsp)
       RSP = BX_CPU_THIS_PTR prev_rsp;
 
+    if (BX_CPU_THIS_PTR last_exception_type == BX_ET_DOUBLE_FAULT)
+    {
+      debug(BX_CPU_THIS_PTR prev_rip); // print debug information to the log
+#if BX_SUPPORT_VMX
+      VMexit_TripleFault();
+#endif
+#if BX_DEBUGGER
+      // trap into debugger (similar as done when PANIC occured)
+      bx_debug_break();
+#endif
+      if (SIM->get_param_bool(BXPN_RESET_ON_TRIPLE_FAULT)->get()) {
+        BX_ERROR(("exception(): 3rd (%d) exception with no resolution, shutdown status is %02xh, resetting", vector, DEV_cmos_get_reg(0x0f)));
+        bx_pc_system.Reset(BX_RESET_HARDWARE);
+      }
+      else {
+        BX_PANIC(("exception(): 3rd (%d) exception with no resolution", vector));
+        BX_ERROR(("WARNING: Any simulation after this point is completely bogus !"));
+        shutdown();
+      }
+      longjmp(BX_CPU_THIS_PTR jmp_buf_env, 1); // go back to main decode loop
+    }
+
     if (vector != BX_DB_EXCEPTION) BX_CPU_THIS_PTR assert_RF();
   }
 
diff --git a/bochs/cpu/svm.cc b/bochs/cpu/svm.cc
index e5339cc07..13d907144 100644
--- a/bochs/cpu/svm.cc
+++ b/bochs/cpu/svm.cc
@@ -630,6 +630,7 @@ void BX_CPU_C::Svm_Vmexit(int reason, Bit64u exitinfo1, Bit64u exitinfo2)
   //
 
   BX_CPU_THIS_PTR EXT = 0;
+  BX_CPU_THIS_PTR last_exception_type = 0;
 
 #if BX_DEBUGGER
   if (BX_CPU_THIS_PTR vmexit_break) {
@@ -744,8 +745,6 @@ void BX_CPU_C::SvmInterceptException(unsigned type, unsigned vector, Bit16u errc
   BX_CPU_THIS_PTR debug_trap = 0; // clear debug_trap field
   BX_CPU_THIS_PTR inhibit_mask = 0;
 
-  BX_CPU_THIS_PTR last_exception_type = 0; // error resolved
-
   Svm_Vmexit(SVM_VMEXIT_EXCEPTION + vector, (errcode_valid ? errcode : 0), qualification);
 }
 
diff --git a/bochs/cpu/vmexit.cc b/bochs/cpu/vmexit.cc
index 9ef9ef83f..cbc67bccf 100644
--- a/bochs/cpu/vmexit.cc
+++ b/bochs/cpu/vmexit.cc
@@ -255,8 +255,6 @@ void BX_CPU_C::VMexit_Event(unsigned type, unsigned vector, Bit16u errcode, bx_b
   BX_CPU_THIS_PTR debug_trap = 0;
   BX_CPU_THIS_PTR inhibit_mask = 0;
 
-  BX_CPU_THIS_PTR last_exception_type = 0; // error resolved
-
   Bit32u interruption_info = vector | (type << 8);
   if (errcode_valid)
     interruption_info |= (1 << 11); // error code delivered
diff --git a/bochs/cpu/vmx.cc b/bochs/cpu/vmx.cc
index d95d766b3..8beae499a 100644
--- a/bochs/cpu/vmx.cc
+++ b/bochs/cpu/vmx.cc
@@ -2244,6 +2244,7 @@ void BX_CPU_C::VMexit(Bit32u reason, Bit64u qualification)
   mask_event(BX_EVENT_INIT); // INIT is disabled in VMX root mode
 
   BX_CPU_THIS_PTR EXT = 0;
+  BX_CPU_THIS_PTR last_exception_type = 0;
 
 #if BX_DEBUGGER
   if (BX_CPU_THIS_PTR vmexit_break) {