Changeset 102963 in vbox for trunk/src

Timestamp:

Jan 19, 2024 5:49:52 AM (11 months ago)

Author:

vboxsync

Message:

VMM/CPUM: bugref:10498 Fix incorrect assertion while mapping MTRRs and comment update.

File:

• trunk/src/VBox/VMM/VMMR3/CPUM.cpp (modified) (2 diffs)

trunk/src/VBox/VMM/VMMR3/CPUM.cpp

@@ -3681 +3681 @@
 
     /*
-     * Until the remainder of the memory fits within 4GB, map regions at
-     * incremental powers of two offsets and sizes.
+     * Map regions at incremental powers of two offsets and sizes.
+     * Note: We cannot map an 8GB region in a 4GB offset.
      */
     uint64_t cbLeft    = cb;
@@ -3700 +3700 @@
 
     /*
-     * Optimally try and map any remaining memory smaller than 4GB.
+     * Optimally try and map any remaining memory that is smaller than
+     * the last power of two offset (size) above.
      */
-    Assert(pMtrrMap->cMtrrs - pMtrrMap->idxMtrr > 0);
-    Assert(cbLeft < _4G);
-    return cpumR3MapMtrrsOptimal(pVM, offRegion, cbLeft, pMtrrMap);
+    if (cbLeft > 0)
+    {
+        Assert(pMtrrMap->cMtrrs - pMtrrMap->idxMtrr > 0);
+        return cpumR3MapMtrrsOptimal(pVM, offRegion, cbLeft, pMtrrMap);
+    }
+    return VINF_SUCCESS;
 }