Changeset 65957 in vbox for trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp

Timestamp:

Mar 6, 2017 8:41:43 PM (8 years ago)

Author:

vboxsync

Message:

PGMPool: Address problem where we would incorrectly try to flush an active CR3 page (or pages in PAE) because we thought it was being reused, which obviously would fail, then pretend we succeeded and restart the instruction. Happend on a STOS during linux bootup (e.g. ubuntu 15.10/amd64). Fix was to extend pgmRZPoolMonitorIsReused with a check on locked pages.

File:

• trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp (modified) (3 diffs)

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

@@ -737 +737 @@
  * @param   pDis        The disassembly info for the faulting instruction.
  * @param   pvFault     The fault address.
+ * @param   pPage       The pool page being accessed.
  *
  * @remark  The REP prefix check is left to the caller because of STOSD/W.
  */
-DECLINLINE(bool) pgmRZPoolMonitorIsReused(PVM pVM, PVMCPU pVCpu, PCPUMCTXCORE pRegFrame, PDISCPUSTATE pDis, RTGCPTR pvFault)
-{
+DECLINLINE(bool) pgmRZPoolMonitorIsReused(PVM pVM, PVMCPU pVCpu, PCPUMCTXCORE pRegFrame, PDISCPUSTATE pDis, RTGCPTR pvFault,
+                                          PPGMPOOLPAGE pPage)
+{
+    /* Locked (CR3, PDPTR*4) should not be reusable.  Considering them as
+       such may cause loops booting tst-ubuntu-15_10-64-efi, ++. */
+    if (pPage->cLocked)
+    {
+        Log2(("pgmRZPoolMonitorIsReused: %RGv (%p) can't have been resued, because it's locked!\n", pvFault, pPage));
+        return false;
+    }
+
 # ifndef IN_RC
     /** @todo could make this general, faulting close to rsp should be a safe reuse heuristic. */
@@ -1188 +1198 @@
              || pgmPoolIsPageLocked(pPage)
             )
-        &&  !(fReused = pgmRZPoolMonitorIsReused(pVM, pVCpu, pRegFrame, pDis, pvFault))
+        &&  !(fReused = pgmRZPoolMonitorIsReused(pVM, pVCpu, pRegFrame, pDis, pvFault, pPage))
         &&  !pgmRZPoolMonitorIsForking(pPool, pDis, GCPhysFault & PAGE_OFFSET_MASK))
     {
@@ -1289 +1299 @@
         &&  (pPage->enmKind == PGMPOOLKIND_PAE_PT_FOR_PAE_PT || pPage->enmKind == PGMPOOLKIND_PAE_PT_FOR_32BIT_PT)
         &&  (   fNotReusedNotForking
-             || (   !pgmRZPoolMonitorIsReused(pVM, pVCpu, pRegFrame, pDis, pvFault)
+             || (   !pgmRZPoolMonitorIsReused(pVM, pVCpu, pRegFrame, pDis, pvFault, pPage)
                  && !pgmRZPoolMonitorIsForking(pPool, pDis, GCPhysFault & PAGE_OFFSET_MASK))
             )