Changeset 23067 in vbox

Timestamp:

Sep 16, 2009 12:54:52 PM (15 years ago)

Author:

vboxsync

Message:

Flush page tables that have been updated with invalid entries.

Location:

trunk/src/VBox/VMM

Files:

• PGMInternal.h (modified) (3 diffs)
• VMMAll/PGMAllPool.cpp (modified) (12 diffs)

trunk/src/VBox/VMM/PGMInternal.h

@@ -3102 +3102 @@
 
 void            pgmPoolAddDirtyPage(PVM pVM, PPGMPOOL pPool, PPGMPOOLPAGE pPage);
-void            pgmPoolResetDirtyPages(PVM pVM, bool fForceRemoval = false);
+void            pgmPoolResetDirtyPages(PVM pVM);
 
 int             pgmR3ExitShadowModeBeforePoolFlush(PVM pVM, PVMCPU pVCpu);
@@ -3197 +3197 @@
  * @param   pPGM        PGM handle.
  * @param   GCPhys      The GC physical address.
- * @param   ppPage      Where to store the page poitner on success.
+ * @param   ppPage      Where to store the page pointer on success.
  */
 DECLINLINE(int) pgmPhysGetPageEx(PPGM pPGM, RTGCPHYS GCPhys, PPPGMPAGE ppPage)
@@ -3237 +3237 @@
  * @param   pPGM        PGM handle.
  * @param   GCPhys      The GC physical address.
- * @param   ppPage      Where to store the page poitner on success.
+ * @param   ppPage      Where to store the page pointer on success.
  * @param   ppRamHint   Where to read and store the ram list hint.
  *                      The caller initializes this to NULL before the call.

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

@@ -1470 +1470 @@
  *
  * @returns nr of changed PTEs
- * @param   pPool       The pool.
- * @param   pPage       The page.
- * @param   pShwPT      The shadow page table (mapping of the page).
- * @param   pGstPT      The guest page table.
- * @param   pOldGstPT   The old cached guest page table.
- */
-DECLINLINE(unsigned) pgmPoolTrackFlushPTPaePae(PPGMPOOL pPool, PPGMPOOLPAGE pPage, PX86PTPAE pShwPT, PCX86PTPAE pGstPT, PCX86PTPAE pOldGstPT)
+ * @param   pPool           The pool.
+ * @param   pPage           The page.
+ * @param   pShwPT          The shadow page table (mapping of the page).
+ * @param   pGstPT          The guest page table.
+ * @param   pOldGstPT       The old cached guest page table.
+ * @param   fAllowRemoval   Bail out as soon as we encounter an invalid PTE
+ * @param   pfFlush         Flush reused page table (out)
+ */
+DECLINLINE(unsigned) pgmPoolTrackFlushPTPaePae(PPGMPOOL pPool, PPGMPOOLPAGE pPage, PX86PTPAE pShwPT, PCX86PTPAE pGstPT, PCX86PTPAE pOldGstPT, bool fAllowRemoval, bool *pfFlush)
 {
     unsigned cChanged = 0;
@@ -1484 +1486 @@
         AssertMsg(!pShwPT->a[i].n.u1Present, ("Unexpected PTE: idx=%d %RX64 (first=%d)\n", i, pShwPT->a[i].u,  pPage->iFirstPresent));
 #endif
+    *pfFlush = false;
+
     for (unsigned i = pPage->iFirstPresent; i < RT_ELEMENTS(pShwPT->a); i++)
     {
+        /* Check the new value written by the guest. If present and with a bogus physical address, then
+         * it's fairly safe to assume the guest is reusing the PT.
+         */
+        if (    fAllowRemoval
+            &&  pGstPT->a[i].n.u1Present)
+        {
+            if (!PGMPhysIsGCPhysValid(pPool->CTX_SUFF(pVM), pGstPT->a[i].u & X86_PTE_PAE_PG_MASK))
+            {
+                *pfFlush = true;
+                return ++cChanged;
+            }
+        }
         if (pShwPT->a[i].n.u1Present)
         {
@@ -1523 +1539 @@
  * @param   pPool           The pool.
  * @param   idxSlot         Dirty array slot index
- * @param   fForceRemoval   Force removal from the dirty page list
- */
-static void pgmPoolFlushDirtyPage(PVM pVM, PPGMPOOL pPool, unsigned idxSlot, bool fForceRemoval = false)
+ * @param   fAllowRemoval   Allow a reused page table to be removed
+ */
+static void pgmPoolFlushDirtyPage(PVM pVM, PPGMPOOL pPool, unsigned idxSlot, bool fAllowRemoval = false)
 {
     PPGMPOOLPAGE pPage;
@@ -1547 +1563 @@
     void *pvShw = PGMPOOL_PAGE_2_LOCKED_PTR(pPool->CTX_SUFF(pVM), pPage);
     void *pvGst;
+    bool  fFlush;
     int rc = PGM_GCPHYS_2_PTR(pPool->CTX_SUFF(pVM), pPage->GCPhys, &pvGst); AssertReleaseRC(rc);
-    unsigned cChanges = pgmPoolTrackFlushPTPaePae(pPool, pPage, (PX86PTPAE)pvShw, (PCX86PTPAE)pvGst, (PCX86PTPAE)&pPool->aDirtyPages[idxSlot][0]);
+    unsigned cChanges = pgmPoolTrackFlushPTPaePae(pPool, pPage, (PX86PTPAE)pvShw, (PCX86PTPAE)pvGst, (PCX86PTPAE)&pPool->aDirtyPages[idxSlot][0], fAllowRemoval, &fFlush);
     STAM_PROFILE_STOP(&pPool->StatTrackDeref,a);
 
     /** Note: we might want to consider keeping the dirty page active in case there were many changes. */
+    if (fFlush)
+    {
+        Assert(fAllowRemoval);
+        Log(("Flush reused page table!\n"));
+        pgmPoolFlushPage(pPool, pPage);
+        STAM_COUNTER_INC(&pPool->StatForceFlushReused);
+        return;
+    }
 
     /* Write protect the page again to catch all write accesses. */
     rc = PGMHandlerPhysicalReset(pVM, pPage->GCPhys);
     Assert(rc == VINF_SUCCESS);
-    pPage->fDirty         = false;
+    pPage->fDirty = false;
 
 #ifdef VBOX_STRICT
@@ -1610 +1635 @@
     {
         STAM_COUNTER_INC(&pPool->StatDirtyPageOverFlowFlush);
-        pgmPoolFlushDirtyPage(pVM, pPool, idxFree, true /* force removal */);
+        pgmPoolFlushDirtyPage(pVM, pPool, idxFree, true /* allow removal of reused page tables*/);
     }
     Assert(pPool->cDirtyPages < RT_ELEMENTS(pPool->aIdxDirtyPages));
@@ -1691 +1716 @@
  *
  * @param   pVM             VM Handle.
- * @param   fForceRemoval   Force removal of all dirty pages
- */
-void pgmPoolResetDirtyPages(PVM pVM, bool fForceRemoval)
+ */
+void pgmPoolResetDirtyPages(PVM pVM)
 {
     PPGMPOOL pPool = pVM->pgm.s.CTX_SUFF(pPool);
@@ -1704 +1728 @@
     Log(("pgmPoolResetDirtyPages\n"));
     for (unsigned i = 0; i < RT_ELEMENTS(pPool->aIdxDirtyPages); i++)
-        pgmPoolFlushDirtyPage(pVM, pPool, i, fForceRemoval);
+        pgmPoolFlushDirtyPage(pVM, pPool, i, true /* allow removal of reused page tables*/);
 
     pPool->idxFreeDirtyPage = 0;
@@ -2259 +2283 @@
 #ifdef PGMPOOL_WITH_OPTIMIZED_DIRTY_PT
         if (pPageHead->fDirty)
-            pgmPoolFlushDirtyPage(pPool->CTX_SUFF(pVM), pPool, pPageHead->idxDirty, true /* force removal */);
+            pgmPoolFlushDirtyPage(pPool->CTX_SUFF(pVM), pPool, pPageHead->idxDirty, false /* do not remove */);
 #endif
 
@@ -2477 +2501 @@
 
 #ifdef PGMPOOL_WITH_OPTIMIZED_DIRTY_PT
-    pgmPoolResetDirtyPages(pVM, true /* force removal. */);
+    pgmPoolResetDirtyPages(pVM);
 #endif
 
@@ -2519 +2543 @@
 
 #ifdef PGMPOOL_WITH_OPTIMIZED_DIRTY_PT
-    pgmPoolResetDirtyPages(pVM, true /* force removal. */);
+    pgmPoolResetDirtyPages(pVM);
 #endif
 
@@ -2894 +2918 @@
 #  ifdef PGMPOOL_WITH_OPTIMIZED_DIRTY_PT
     if (pPage->fDirty)
-        pgmPoolFlushDirtyPage(pPool->CTX_SUFF(pVM), pPool, pPage->idxDirty, true /* force removal */);
+        pgmPoolFlushDirtyPage(pPool->CTX_SUFF(pVM), pPool, pPage->idxDirty, false /* do not remove */);
 #  endif
 
@@ -4471 +4495 @@
 #ifdef PGMPOOL_WITH_OPTIMIZED_DIRTY_PT
     if (pPage->fDirty)
-        pgmPoolFlushDirtyPage(pVM, pPool, pPage->idxDirty, true /* force removal */);
+        pgmPoolFlushDirtyPage(pVM, pPool, pPage->idxDirty, false /* do not remove */);
 #endif