Changeset 35756 in vbox for trunk/src/VBox/Devices

Timestamp:

Jan 28, 2011 12:29:38 PM (14 years ago)

Author:

vboxsync

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

69717

Message:

BusLogic: Fix SMP race which results in a guest hang

File:

• trunk/src/VBox/Devices/Storage/DevBusLogic.cpp (modified) (2 diffs)

trunk/src/VBox/Devices/Storage/DevBusLogic.cpp

@@ -2345 +2345 @@
 {
     PBUSLOGIC  pBusLogic = PDMINS_2_DATA(pDevIns, PBUSLOGIC);
-
-    AssertMsg(pBusLogic->cMailboxesReady > 0, ("Got notification without any mailboxes ready\n"));
+    uint32_t cMailboxesReady = 0;
 
     /* Reset notification send flag now. */
+    Assert(pBusLogic->fNotificationSend);
     ASMAtomicXchgBool(&pBusLogic->fNotificationSend, false);
+
+    /*
+     * It is possible that there is a notification send but that there is no mailbox ready
+     * in the SMP case. Just do nothing.
+     */
+    cMailboxesReady = ASMAtomicXchgU32(&pBusLogic->cMailboxesReady, 0);
+    if (!cMailboxesReady)
+        return true;
 
     /* Process mailboxes. */
@@ -2358 +2366 @@
         rc = buslogicProcessMailboxNext(pBusLogic);
         AssertMsgRC(rc, ("Processing mailbox failed rc=%Rrc\n", rc));
-    } while (ASMAtomicDecU32(&pBusLogic->cMailboxesReady) > 0);
+    } while (--cMailboxesReady > 0);
 
     return true;