Changeset 82975 in vbox for trunk/src/VBox/VMM/VMMR0

Timestamp:

Feb 4, 2020 12:35:27 PM (5 years ago)

Author:

vboxsync

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

135984

Message:

VMM/GMMR0: Use the chunk list rather than the AVL tree in GMMR0FindDuplicatePageReq to look for duplicate pages. This will restricts the AVL tree to lookups and make it simpler to protect. bugref:9627

File:

• trunk/src/VBox/VMM/VMMR0/GMMR0.cpp (modified) (6 diffs)

trunk/src/VBox/VMM/VMMR0/GMMR0.cpp

@@ -5354 +5354 @@
 
 /**
- * RTAvlU32DoWithAll callback.
- *
- * @returns 0
- * @param   pNode       The node to search.
- * @param   pvUser      Pointer to the input argument packet.
- */
-static DECLCALLBACK(int) gmmR0FindDupPageInChunk(PAVLU32NODECORE pNode, void *pvUser)
-{
-    PGMMCHUNK           pChunk = (PGMMCHUNK)pNode;
-    GMMFINDDUPPAGEINFO *pArgs  = (GMMFINDDUPPAGEINFO *)pvUser;
-    PGVM                pGVM   = pArgs->pGVM;
-    PGMM                pGMM   = pArgs->pGMM;
-    uint8_t            *pbChunk;
-
+ * Worker for GMMR0FindDuplicatePageReq.
+ *
+ * @returns true if duplicate, false if not.
+ */
+static bool gmmR0FindDupPageInChunk(PGMM pGMM, PGVM pGVM, PGMMCHUNK pChunk, uint8_t const *pbSourcePage)
+{
+    bool fFoundDuplicate = false;
     /* Only take chunks not mapped into this VM process; not entirely correct. */
+    uint8_t *pbChunk;
     if (!gmmR0IsChunkMapped(pGMM, pGVM, pChunk, (PRTR3PTR)&pbChunk))
     {
@@ -5377 +5371 @@
              * Look for duplicate pages
              */
-            unsigned iPage = (GMM_CHUNK_SIZE >> PAGE_SHIFT);
+            uintptr_t iPage = (GMM_CHUNK_SIZE >> PAGE_SHIFT);
             while (iPage-- > 0)
             {
@@ -5383 +5377 @@
                 {
                     uint8_t *pbDestPage = pbChunk + (iPage  << PAGE_SHIFT);
-
-                    if (!memcmp(pArgs->pSourcePage, pbDestPage, PAGE_SIZE))
+                    if (!memcmp(pbSourcePage, pbDestPage, PAGE_SIZE))
                     {
-                        pArgs->fFoundDuplicate = true;
+                        fFoundDuplicate = true;
                         break;
                     }
@@ -5394 +5387 @@
         }
     }
-    return pArgs->fFoundDuplicate; /* (stops search if true) */
+    return fFoundDuplicate;
 }
 
@@ -5436 +5429 @@
                 if (pPage)
                 {
+                    /*
+                     * Walk the chunks
+                     */
                     GMMFINDDUPPAGEINFO Args;
                     Args.pGVM            = pGVM;
@@ -5441 +5437 @@
                     Args.pSourcePage     = pbSourcePage;
                     Args.fFoundDuplicate = false;
-                    RTAvlU32DoWithAll(&pGMM->pChunks, true /* fFromLeft */, gmmR0FindDupPageInChunk, &Args);
-
-                    pReq->fDuplicate = Args.fFoundDuplicate;
+
+                    PGMMCHUNK pChunk;
+                    pReq->fDuplicate = false;
+                    RTListForEach(&pGMM->ChunkList, pChunk, GMMCHUNK, ListNode)
+                    {
+                        if (gmmR0FindDupPageInChunk(pGMM, pGVM, pChunk, pbSourcePage))
+                        {
+                            pReq->fDuplicate = true;
+                            break;
+                        }
+                    }
                 }
                 else