Changeset 20749 in vbox

Timestamp:

Jun 21, 2009 8:57:37 PM (16 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

48865

Message:

REMNotifyInvalidatePage: Don't overflow aGCPtrInvalidatedPages. 2xtodo

Location:

trunk/src/VBox/VMM

Files:

• REMInternal.h (modified) (1 diff)
• VMMAll/REMAll.cpp (modified) (1 diff)

trunk/src/VBox/VMM/REMInternal.h

@@ -165 +165 @@
 
     /** Number of recorded invlpg instructions. */
-    uint32_t                cInvalidatedPages;
+    uint32_t volatile       cInvalidatedPages;
 #if HC_ARCH_BITS == 32
     uint32_t                uPadding2;

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

@@ -47 +47 @@
 VMMDECL(int) REMNotifyInvalidatePage(PVM pVM, RTGCPTR GCPtrPage)
 {
-    if (    pVM->rem.s.cInvalidatedPages < RT_ELEMENTS(pVM->rem.s.aGCPtrInvalidatedPages)
-        &&  EMTryEnterRemLock(pVM) == VINF_SUCCESS) /* if this fails, then we'll just flush the tlb as we don't want to waste time here. */
-    {
-        /*
-         * We sync them back in REMR3State.
-         */
-        pVM->rem.s.aGCPtrInvalidatedPages[pVM->rem.s.cInvalidatedPages++] = GCPtrPage;
+    /*
+     * Try take the REM lock and push the address onto the array.
+     */
+    if (   pVM->rem.s.cInvalidatedPages < RT_ELEMENTS(pVM->rem.s.aGCPtrInvalidatedPages)
+        && EMTryEnterRemLock(pVM) == VINF_SUCCESS)
+    {
+        uint32_t iPage = pVM->rem.s.cInvalidatedPages;
+        if (iPage < RT_ELEMENTS(pVM->rem.s.aGCPtrInvalidatedPages))
+        {
+            ASMAtomicWriteU32(&pVM->rem.s.cInvalidatedPages, iPage + 1);
+            pVM->rem.s.aGCPtrInvalidatedPages[iPage] = GCPtrPage;
+
+            EMRemUnlock(pVM);
+            return VINF_SUCCESS;
+        }
+
+        CPUMSetChangedFlags(VMMGetCpu(pVM), CPUM_CHANGED_GLOBAL_TLB_FLUSH); /** @todo this should be flagged globally, not locally! ... this array should be per-cpu technically speaking. */
+        ASMAtomicWriteU32(&pVM->rem.s.cInvalidatedPages, 0); /** @todo leave this alone? Optimize this code? */
+
         EMRemUnlock(pVM);
     }
     else
     {
-        /* Tell the recompiler to flush its TLB. */
+        /* Fallback: Simply tell the recompiler to flush its TLB. */
         CPUMSetChangedFlags(VMMGetCpu(pVM), CPUM_CHANGED_GLOBAL_TLB_FLUSH);
-        pVM->rem.s.cInvalidatedPages = 0;
+        ASMAtomicWriteU32(&pVM->rem.s.cInvalidatedPages, 0); /** @todo leave this alone?! Optimize this code? */
     }