Changeset 21174 in vbox for trunk

Timestamp:

Jul 2, 2009 3:45:46 PM (16 years ago)

Author:

vboxsync

Message:

Preread opcode bytes when disassembling instructions. PGMPhysSimpleReadGCPtr is quite expensive.

File:

• trunk/src/VBox/VMM/VMMAll/EMAll.cpp (modified) (6 diffs)

trunk/src/VBox/VMM/VMMAll/EMAll.cpp

@@ -70 +70 @@
 typedef struct
 {
-    PVM     pVM;
-    PVMCPU  pVCpu;
+    PVM         pVM;
+    PVMCPU      pVCpu;
+    RTGCPTR     GCPtr;
+    uint8_t     aOpcode[8];
 } EMDISSTATE, *PEMDISSTATE;
 
@@ -125 +127 @@
 
 # ifdef IN_RING0
-    int rc = PGMPhysSimpleReadGCPtr(pVCpu, pDest, pSrc, cb);
+    int rc;
+
+    if (    pState->GCPtr
+        &&  pSrc + cb <= pState->GCPtr + sizeof(pState->aOpcode))
+    {
+        unsigned offset = pSrc - pState->GCPtr;
+
+        Assert(pSrc >= pState->GCPtr);
+
+        for (unsigned i=0; i<cb; i++)
+        {
+            pDest[i] = pState->aOpcode[offset + i];
+        }
+        return VINF_SUCCESS;
+    }
+
+    rc = PGMPhysSimpleReadGCPtr(pVCpu, pDest, pSrc, cb);
     AssertMsgRC(rc, ("PGMPhysSimpleReadGCPtr failed for pSrc=%RGv cb=%x rc=%d\n", pSrc, cb, rc));
 # else /* IN_RING3 */
@@ -135 +153 @@
     else
     {
-        for (uint32_t i = 0; i < cb; i++)
+        for (unsigned i = 0; i < cb; i++)
         {
             uint8_t opcode;
@@ -153 +171 @@
     State.pVM   = pVM;
     State.pVCpu = pVCpu;
+    int rc = PGMPhysSimpleReadGCPtr(pVCpu, &State.aOpcode, InstrGC, sizeof(State.aOpcode));
+    if (RT_SUCCESS(rc))
+        State.GCPtr = InstrGC;
+    else
+        State.GCPtr = NULL;
 
     return DISCoreOneEx(InstrGC, pDis->mode, EMReadBytes, &State, pDis, pOpsize);
@@ -213 +236 @@
 VMMDECL(int) EMInterpretDisasOneEx(PVM pVM, PVMCPU pVCpu, RTGCUINTPTR GCPtrInstr, PCCPUMCTXCORE pCtxCore, PDISCPUSTATE pDis, unsigned *pcbInstr)
 {
+    int rc;
+
 #ifndef IN_RC
     EMDISSTATE State;
@@ -218 +243 @@
     State.pVM   = pVM;
     State.pVCpu = pVCpu;
-#endif
-
-    int rc = DISCoreOneEx(GCPtrInstr, SELMGetCpuModeFromSelector(pVM, pCtxCore->eflags, pCtxCore->cs, (PCPUMSELREGHID)&pCtxCore->csHid),
+
+    rc = PGMPhysSimpleReadGCPtr(pVCpu, &State.aOpcode, GCPtrInstr, sizeof(State.aOpcode));
+    if (RT_SUCCESS(rc))
+        State.GCPtr = GCPtrInstr;
+    else
+        State.GCPtr = NULL;
+#endif
+
+    rc = DISCoreOneEx(GCPtrInstr, SELMGetCpuModeFromSelector(pVM, pCtxCore->eflags, pCtxCore->cs, (PCPUMSELREGHID)&pCtxCore->csHid),
 #ifdef IN_RC
                           NULL, NULL,