Changeset 68853 in vbox for trunk/src

Timestamp:

Sep 25, 2017 1:10:41 PM (8 years ago)

Author:

vboxsync

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

118107

Message:

VMMR3EmtRendezvous: Pretend we're a single CPU config when called during vmR3Destroy after the EMTs have started terminating.

Location:

trunk/src/VBox/VMM

Files:

• VMMR3/VM.cpp (modified) (1 diff)
• VMMR3/VMEmt.cpp (modified) (3 diffs)
• VMMR3/VMM.cpp (modified) (2 diffs)
• include/VMInternal.h (modified) (2 diffs)

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

@@ -2535 +2535 @@
         LogFlow(("vmR3Destroy: returning %Rrc\n", VINF_EM_TERMINATE));
     }
+
+    /*
+     * Decrement the active EMT count here.
+     */
+    PUVMCPU pUVCpu = &pUVM->aCpus[pVCpu->idCpu];
+    if (!pUVCpu->vm.s.fBeenThruVmDestroy)
+    {
+        pUVCpu->vm.s.fBeenThruVmDestroy = true;
+        ASMAtomicDecU32(&pUVM->vm.s.cActiveEmts);
+    }
+    else
+        AssertFailed();
+
     return VINF_EM_TERMINATE;
 }

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

@@ -94 +94 @@
     Log(("vmR3EmulationThread: Emulation thread starting the days work... Thread=%#x pUVM=%p\n", hThreadSelf, pUVM));
     VMSTATE enmBefore = VMSTATE_CREATED; /* (only used for logging atm.) */
+    ASMAtomicIncU32(&pUVM->vm.s.cActiveEmts);
     for (;;)
     {
@@ -244 +245 @@
 
     } /* forever */
+
+
+    /*
+     * Decrement the active EMT count if we haven't done it yet in vmR3Destroy.
+     */
+    if (!pUVCpu->vm.s.fBeenThruVmDestroy)
+        ASMAtomicDecU32(&pUVM->vm.s.cActiveEmts);
 
 
@@ -1381 +1389 @@
 }
 
+
+/**
+ * Returns the number of active EMTs.
+ *
+ * This is used by the rendezvous code during VM destruction to avoid waiting
+ * for EMTs that aren't around any more.
+ *
+ * @returns Number of active EMTs.  0 if invalid parameter.
+ * @param   pUVM                The user mode VM structure.
+ */
+VMMR3_INT_DECL(uint32_t) VMR3GetActiveEmts(PUVM pUVM)
+{
+    UVM_ASSERT_VALID_EXT_RETURN(pUVM, 0);
+    return pUVM->vm.s.cActiveEmts;
+}
+

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

@@ -2160 +2160 @@
     PVMCPU pVCpu = VMMGetCpu(pVM);
     if (!pVCpu)
+    {
         /*
          * Forward the request to an EMT thread.
          */
-    {
         Log(("VMMR3EmtRendezvous: %#x non-EMT\n", fFlags));
         if (!(fFlags & VMMEMTRENDEZVOUS_FLAGS_PRIORITY))
@@ -2171 +2171 @@
         Log(("VMMR3EmtRendezvous: %#x non-EMT returns %Rrc\n", fFlags, VBOXSTRICTRC_VAL(rcStrict)));
     }
-    else if (pVM->cCpus == 1)
+    else if (   pVM->cCpus == 1
+             || (   pVM->enmVMState == VMSTATE_DESTROYING
+                 && VMR3GetActiveEmts(pVM->pUVM) < pVM->cCpus ) )
     {
         /*
          * Shortcut for the single EMT case.
+         *
+         * We also ends up here if EMT(0) (or others) tries to issue a rendezvous
+         * during vmR3Destroy after other emulation threads have started terminating.
          */
         if (!pVCpu->vmm.s.fInRendezvous)

trunk/src/VBox/VMM/include/VMInternal.h

@@ -191 +191 @@
     /** The reference count of the UVM handle. */
     volatile uint32_t               cUvmRefs;
+
+    /** Number of active EMTs. */
+    volatile uint32_t               cActiveEmts;
 
 # ifdef VBOX_WITH_STATISTICS
@@ -342 +345 @@
     /** Wait/Idle indicator. */
     bool volatile                   fWait;
+    /** Set if we've been thru vmR3Destroy and decremented the active EMT count
+     *  already. */
+    bool volatile                   fBeenThruVmDestroy;
     /** Align the next bit. */
-    bool                            afAlignment[HC_ARCH_BITS == 32 ? 3 : 7];
+    bool                            afAlignment[HC_ARCH_BITS == 32 ? 2 : 6];
 
     /** @name Generic Halt data