Changeset 23099 in vbox for trunk/src

Timestamp:

Sep 17, 2009 2:39:06 PM (15 years ago)

Author:

vboxsync

Message:

PATM: implemented couple tweaks to make NetBSD bootable (still some spurious segfaults)

Location:

trunk/src/VBox

Files:

• Main/ConsoleImpl2.cpp (modified) (3 diffs)
• VMM/CPUM.cpp (modified) (2 diffs)
• VMM/PATM/PATM.cpp (modified) (3 diffs)
• VMM/PATM/PATMInternal.h (modified) (2 diffs)

trunk/src/VBox/Main/ConsoleImpl2.cpp

@@ -244 +244 @@
     rc = CFGMR3InsertInteger(pRoot, "CSAMEnabled",          1);     /* boolean */   RC_CHECK();
 
+    PCFGMNODE pCPUM;
+    rc = CFGMR3InsertNode(pRoot, "CPUM", &pCPUM);                                   RC_CHECK();
+
     if (osTypeId == "WindowsNT4")
     {
@@ -251 +254 @@
          */
         LogRel(("Limiting CPUID leaf count for NT4 guests\n"));
-        PCFGMNODE pCPUM;
-        rc = CFGMR3InsertNode(pRoot, "CPUM", &pCPUM);                               RC_CHECK();
         rc = CFGMR3InsertInteger(pCPUM, "NT4LeafLimit", true);                      RC_CHECK();
     }
@@ -273 +274 @@
     rc = CFGMR3InsertInteger(pRoot, "HwVirtExtForced",      fHwVirtExtForced);      RC_CHECK();
 #endif
+
+    if (!fHWVirtExEnabled && osTypeId == "NetBSD")
+    {
+        /*
+         * Use additional NetBSD-specific raw mode heuristics in PATM and CPUM,
+         * see #4291.
+         */
+        PCFGMNODE pPATM;
+        rc = CFGMR3InsertNode(pRoot, "PATM", &pPATM);                               RC_CHECK();
+        rc = CFGMR3InsertInteger(pPATM, "SearchImmediatesBackward", 1);                      RC_CHECK();
+        rc = CFGMR3InsertInteger(pCPUM, "HideCX8", 1);                      RC_CHECK();
+    }
+
 
     PCFGMNODE pHWVirtExt;

trunk/src/VBox/VMM/CPUM.cpp

@@ -528 +528 @@
     }
 
+    PCFGMNODE pCpum = CFGMR3GetChild(CFGMR3GetRoot(pVM), "CPUM");
     /** @cfgm{/CPUM/NT4LeafLimit, boolean, false}
      * Limit the number of standard CPUID leafs to 0..2 to prevent NT4 from
@@ -535 +536 @@
      */
     bool fNt4LeafLimit;
-    CFGMR3QueryBoolDef(CFGMR3GetChild(CFGMR3GetRoot(pVM), "CPUM"), "NT4LeafLimit", &fNt4LeafLimit, false);
+    CFGMR3QueryBoolDef(pCpum, "NT4LeafLimit", &fNt4LeafLimit, false);
     if (fNt4LeafLimit)
         pCPUM->aGuestCpuIdStd[0].eax = 2;
+
+    /**
+     * @todo: very hacky, may need to change, once better understand real reason
+     */
+    bool fHideCX8;
+    CFGMR3QueryBoolDef(pCpum, "HideCX8", &fHideCX8, false);
+    if (fHideCX8)
+        pCPUM->aGuestCpuIdStd[1].edx &= ~X86_CPUID_FEATURE_EDX_CX8;
 
     /*

trunk/src/VBox/VMM/PATM/PATM.cpp

@@ -167 +167 @@
 # endif
 #endif
+    pVM->patm.s.uPATMFlags = 0;
+    bool fSearchBackward;
+    CFGMR3QueryBoolDef(CFGMR3GetChild(CFGMR3GetRoot(pVM), "PATM"), "SearchImmediatesBackward", &fSearchBackward, false);
+    if (fSearchBackward)
+        pVM->patm.s.uPATMFlags |= PATMGFL_SEARCH_IMM_BACKWARD;
 
     rc = patmReinit(pVM);
@@ -1546 +1551 @@
 
 /**
+ * Checks if few instructions before patch contain something
+ * which looks like immediate referring potential patch instruction
+ *
+ * @returns boolean
+ * @param   pVM         The VM to operate on.
+ * @param   pInstrGC    Guest context pointer to instruction
+ */
+static bool patmHasImmsReferringPatch(PVM pVM, RCPTRTYPE(uint8_t *) pInstrGC)
+{
+    int rc;
+    uint32_t value;
+
+    if (!(pVM->patm.s.uPATMFlags & PATMGFL_SEARCH_IMM_BACKWARD))
+        return false;
+
+    PVMCPU pCpu = VMMGetCpu0(pVM);
+    for (int i = 4; i < 12; i++)
+    {
+        rc = PGMPhysSimpleReadGCPtr(pCpu, &value, pInstrGC - i, 4);
+        if (rc == VINF_SUCCESS)
+        {
+            if ((uint32_t)(value-(uint32_t)pInstrGC) < 6)
+                return true;
+        }
+        else
+            break;
+    }
+    return false;
+}
+
+/**
  * Recompiles the instructions in a code block
  *
@@ -1573 +1609 @@
         Log(("patmRecompileCallback: jump to code we've recompiled before %RRv!\n", pCurInstrGC));
         return patmPatchGenRelJump(pVM, pPatch, pCurInstrGC, OP_JMP, !!(pCpu->prefix & PREFIX_OPSIZE));
+    }
+
+
+    if (patmHasImmsReferringPatch(pVM, pInstrGC))
+    {
+        pPatch->flags |= PATMFL_INT3_REPLACEMENT_BLOCK;
     }
 

trunk/src/VBox/VMM/PATM/PATMInternal.h

@@ -79 +79 @@
 #define PATMFL_EXTERNAL_JUMP_INSIDE         RT_BIT_64(33) /** A trampoline patch was created that jumps to an instruction in the patch block */
 #define PATMFL_CODE_REFERENCED              RT_BIT_64(34) /** patch block referenced (called, jumped to) by another patch. */
+
+/* Global flags, affect PATM behavior */
+#define PATMGFL_SEARCH_IMM_BACKWARD         RT_BIT_32(0)  /** search backward from priveledged insn for immediates referring inside patch */
 
 #define SIZEOF_NEARJUMP8                   2 //opcode byte + 1 byte relative offset
@@ -520 +523 @@
     STAMCOUNTER             StatFunctionLookupInsert;
     uint32_t                StatU32FunctionMaxSlotsUsed;
-    uint32_t                Alignment0; /**< Align the structure size on a 8-byte boundrary. */
+    uint32_t                uPATMFlags; 
 } PATM, *PPATM;