Changeset 17622 in vbox for trunk/src/VBox/VMM/PGMMap.cpp

Timestamp:

Mar 10, 2009 12:32:23 PM (16 years ago)

Author:

vboxsync

Message:

Simple check added to make sure we don't bounce back and forth between hypervisor mappings that have caused conflicts in the past.

File:

• trunk/src/VBox/VMM/PGMMap.cpp (modified) (5 diffs)

trunk/src/VBox/VMM/PGMMap.cpp

@@ -1070 +1070 @@
 }
 
+/**
+ * Checks if a new mapping address wasn't previously used and caused a clash with guest mappings.
+ *
+ * @returns VBox status code.
+ * @param   pMapping            The mapping which conflicts.
+ * @param   GCPtr               New mapping address to try
+ */
+bool pgmR3MapIsKnownConflictAddress(PPGMMAPPING pMapping, RTGCPTR GCPtr)
+{
+    for (int i=0;i<RT_ELEMENTS(pMapping->GCPtrConflict);i++)
+    {
+        if (GCPtr == pMapping->GCPtrConflict[i])
+            return true;
+    }
+    return false;
+}
 
 /**
@@ -1086 +1102 @@
     STAM_PROFILE_START(&pVM->pgm.s.StatR3ResolveConflict, a);
 
+    pMapping->GCPtrConflict[pMapping->cConflicts & (PGMMAPPING_CONFLICT_MAX-1)] = GCPtrOldMapping;
+    pMapping->cConflicts++;
+
     /*
      * Scan for free page directory entries.
@@ -1098 +1117 @@
         if (pPDSrc->a[iPDNew].n.u1Present)
             continue;
+
+        if (pgmR3MapIsKnownConflictAddress(pMapping, iPDNew << X86_PD_SHIFT))
+            continue;
+
         if (cPTs > 1)
         {
@@ -1152 +1175 @@
     STAM_PROFILE_START(&pVM->pgm.s.StatR3ResolveConflict, a);
 
+    pMapping->GCPtrConflict[pMapping->cConflicts & (PGMMAPPING_CONFLICT_MAX-1)] = GCPtrOldMapping;
+    pMapping->cConflicts++;
+
     for (int iPDPTE = X86_PG_PAE_PDPE_ENTRIES - 1; iPDPTE >= 0; iPDPTE--)
     {
@@ -1171 +1197 @@
             /* Ugly assumption that mappings start on a 4 MB boundary. */
             if (iPDNew & 1)
+                continue;
+
+            if (pgmR3MapIsKnownConflictAddress(pMapping, ((RTGCPTR32)iPDPTE << X86_PDPT_SHIFT) + (iPDNew << X86_PD_PAE_SHIFT)))
                 continue;