Changeset 27038 in vbox

Timestamp:

Mar 4, 2010 2:48:14 PM (15 years ago)

Author:

vboxsync

Message:

Try to reuse a 2mb large page if it was previously disabled for monitoring purposes.

Location:

trunk/src/VBox/VMM

Files:

• PGM.cpp (modified) (1 diff)
• PGMInternal.h (modified) (2 diffs)
• VMMAll/PGMAllBth.h (modified) (1 diff)
• VMMAll/PGMAllPhys.cpp (modified) (1 diff)
• VMMAll/PGMAllPool.cpp (modified) (1 diff)

trunk/src/VBox/VMM/PGM.cpp

@@ -1582 +1582 @@
     STAM_REL_REG(pVM, &pPGM->StatLargePageReused,                STAMTYPE_COUNTER, "/PGM/LargePage/Reused",              STAMUNIT_OCCURENCES, "The number of times we've reused a large page.");
     STAM_REL_REG(pVM, &pPGM->StatLargePageRefused,               STAMTYPE_COUNTER, "/PGM/LargePage/Refused",             STAMUNIT_OCCURENCES, "The number of times we couldn't use a large page.");
+    STAM_REL_REG(pVM, &pPGM->StatLargePageRecheck,               STAMTYPE_COUNTER, "/PGM/LargePage/Recheck",             STAMUNIT_OCCURENCES, "The number of times we've rechecked a disabled large page.");    
 
     /* Live save */

trunk/src/VBox/VMM/PGMInternal.h

@@ -2789 +2789 @@
     STAMCOUNTER                     StatLargePageReused;                /**< The number of large pages we've reused.*/
     STAMCOUNTER                     StatLargePageRefused;               /**< The number of times we couldn't use a large page.*/
+    STAMCOUNTER                     StatLargePageRecheck;               /**< The number of times we rechecked a disabled large page.*/
     /** @} */
 
@@ -3332 +3333 @@
 int             pgmPhysAllocPage(PVM pVM, PPGMPAGE pPage, RTGCPHYS GCPhys);
 int             pgmPhysAllocLargePage(PVM pVM, RTGCPHYS GCPhys);
+int             pgmPhysIsValidLargePage(PVM pVM, RTGCPHYS GCPhys, PPGMPAGE pLargePage);
 int             pgmPhysPageLoadIntoTlb(PPGM pPGM, RTGCPHYS GCPhys);
 int             pgmPhysPageLoadIntoTlbWithPage(PPGM pPGM, PPGMPAGE pPage, RTGCPHYS GCPhys);

trunk/src/VBox/VMM/VMMAll/PGMAllBth.h

@@ -2975 +2975 @@
             }
             else
+            if (PGM_PAGE_GET_PDE_TYPE(pPage) == PGM_PAGE_PDE_TYPE_PDE_DISABLED)
+            {
+                /* Recheck the entire 2 MB range to see if we can use it again as a large page. */
+                rc = pgmPhysIsValidLargePage(pVM, GCPtrPage, pPage);
+                if (RT_SUCCESS(rc))
+                {
+                    Assert(PGM_PAGE_GET_STATE(pPage) == PGM_PAGE_STATE_ALLOCATED);
+                    Assert(PGM_PAGE_GET_PDE_TYPE(pPage) == PGM_PAGE_PDE_TYPE_PDE);
+                    HCPhys = PGM_PAGE_GET_HCPHYS(pPage);
+                }
+            }
+            else
             if (PGMIsUsingLargePages(pVM))
             {

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

@@ -551 +551 @@
     return VERR_PGM_INVALID_LARGE_PAGE_RANGE;
 }
+
+/**
+ * Recheck the entire 2 MB range to see if we can use it again as a large page.
+ *
+ * @returns The following VBox status codes.
+ * @retval  VINF_SUCCESS on success, the large page can be used again
+ * @retval  VERR_PGM_INVALID_LARGE_PAGE_RANGE if it can't be reused
+ *
+ * @param   pVM         The VM address.
+ * @param   GCPhys      The address of the page.
+ * @param   pLargePage  Page structure of the base page
+ */
+int pgmPhysIsValidLargePage(PVM pVM, RTGCPHYS GCPhys, PPGMPAGE pLargePage)
+{
+    unsigned i;
+
+    STAM_REL_COUNTER_INC(&pVM->pgm.s.StatLargePageRecheck);
+
+    GCPhys &= X86_PDE2M_PAE_PG_MASK;
+
+    /* Check the base page. */
+    Assert(PGM_PAGE_GET_PDE_TYPE(pLargePage) == PGM_PAGE_PDE_TYPE_PDE_DISABLED);
+    if (    PGM_PAGE_GET_STATE(pLargePage) != PGM_PAGE_STATE_ALLOCATED
+        ||  PGM_PAGE_GET_TYPE(pLargePage) != PGMPAGETYPE_RAM
+        ||  PGM_PAGE_GET_HNDL_PHYS_STATE(pLargePage) != PGM_PAGE_HNDL_PHYS_STATE_NONE)
+    {
+        LogFlow(("pgmPhysIsValidLargePage: checks failed for base page %x %x %x\n", PGM_PAGE_GET_STATE(pLargePage), PGM_PAGE_GET_TYPE(pLargePage), PGM_PAGE_GET_HNDL_PHYS_STATE(pLargePage)));
+        return VERR_PGM_INVALID_LARGE_PAGE_RANGE;
+    }
+
+    /* Check all remaining pages in the 2 MB range. */
+    GCPhys += PAGE_SIZE;
+    for (i = 1; i < _2M/PAGE_SIZE; i++)
+    {
+        PPGMPAGE pPage;
+        int rc = pgmPhysGetPageEx(&pVM->pgm.s, GCPhys, &pPage);
+        AssertRCBreak(rc);
+
+        if (    PGM_PAGE_GET_STATE(pPage) != PGM_PAGE_STATE_ALLOCATED
+            ||  PGM_PAGE_GET_PDE_TYPE(pPage) != PGM_PAGE_PDE_TYPE_PDE
+            ||  PGM_PAGE_GET_TYPE(pPage) != PGMPAGETYPE_RAM
+            ||  PGM_PAGE_GET_HNDL_PHYS_STATE(pPage) != PGM_PAGE_HNDL_PHYS_STATE_NONE)
+        {
+            LogFlow(("pgmPhysIsValidLargePage: checks failed for page %d; %x %x %x\n", i, PGM_PAGE_GET_STATE(pPage), PGM_PAGE_GET_TYPE(pPage), PGM_PAGE_GET_HNDL_PHYS_STATE(pPage)));
+            break;
+        }
+
+        GCPhys += PAGE_SIZE;
+    }
+    if (i == _2M/PAGE_SIZE)
+    {
+        PGM_PAGE_SET_PDE_TYPE(pLargePage, PGM_PAGE_PDE_TYPE_PDE);
+        Log(("pgmPhysIsValidLargePage: page %RGp can be reused!\n", GCPhys));
+        return VINF_SUCCESS;
+    }
+
+    return VERR_PGM_INVALID_LARGE_PAGE_RANGE;
+}
+
 #endif /* PGM_WITH_LARGE_PAGES */
 

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

@@ -3296 +3296 @@
         Log(("pgmPoolTrackUpdateGCPhys: update large page PDE for %RGp (%RGp)\n", GCPhysBase, GCPhysPage));
 
-        /* Mark the large page as disabled as we need to break it up to change a single page in the 2 MB range. */
-        PGM_PAGE_SET_PDE_TYPE(pPhysBase, PGM_PAGE_PDE_TYPE_PDE_DISABLED);
-
-        /* Update the base as that *only* that one has a reference and there's only one PDE to clear. */
-        rc = pgmPoolTrackUpdateGCPhys(pVM, GCPhysBase, pPhysBase, fFlushPTEs, pfFlushTLBs);
-
-        *pfFlushTLBs = true;
-        pgmUnlock(pVM);
-        return rc;
+        if (PGM_PAGE_GET_PDE_TYPE(pPhysBase) == PGM_PAGE_PDE_TYPE_PDE)
+        {
+            /* Mark the large page as disabled as we need to break it up to change a single page in the 2 MB range. */
+            PGM_PAGE_SET_PDE_TYPE(pPhysBase, PGM_PAGE_PDE_TYPE_PDE_DISABLED);
+
+            /* Update the base as that *only* that one has a reference and there's only one PDE to clear. */
+            rc = pgmPoolTrackUpdateGCPhys(pVM, GCPhysBase, pPhysBase, fFlushPTEs, pfFlushTLBs);
+
+            *pfFlushTLBs = true;
+            pgmUnlock(pVM);
+            return rc;
+        }
     }
 #else