Index: /trunk/include/VBox/vmm/pdmusb.h
===================================================================
--- /trunk/include/VBox/vmm/pdmusb.h	(revision 37858)
+++ /trunk/include/VBox/vmm/pdmusb.h	(revision 37859)
@@ -630,4 +630,24 @@
 
     /**
+     * Creates a PDM thread.
+     *
+     * This differs from the RTThreadCreate() API in that PDM takes care of suspending,
+     * resuming, and destroying the thread as the VM state changes.
+     *
+     * @returns VBox status code.
+     * @param   pDevIns             The device instance.
+     * @param   ppThread            Where to store the thread 'handle'.
+     * @param   pvUser              The user argument to the thread function.
+     * @param   pfnThread           The thread function.
+     * @param   pfnWakeup           The wakup callback. This is called on the EMT
+     *                              thread when a state change is pending.
+     * @param   cbStack             See RTThreadCreate.
+     * @param   enmType             See RTThreadCreate.
+     * @param   pszName             See RTThreadCreate.
+     */
+    DECLR3CALLBACKMEMBER(int, pfnThreadCreate,(PPDMUSBINS pUsbIns, PPPDMTHREAD ppThread, void *pvUser, PFNPDMTHREADUSB pfnThread,
+                                               PFNPDMTHREADWAKEUPUSB pfnWakeup, size_t cbStack, RTTHREADTYPE enmType, const char *pszName));
+
+    /**
      * Set up asynchronous handling of a suspend, reset or power off notification.
      *
@@ -662,5 +682,5 @@
 
 /** Current USBHLP version number. */
-#define PDM_USBHLP_VERSION                      PDM_VERSION_MAKE(0xeefe, 1, 0)
+#define PDM_USBHLP_VERSION                      PDM_VERSION_MAKE(0xeefe, 2, 0)
 
 #endif /* IN_RING3 */
@@ -842,4 +862,14 @@
 
 /**
+ * @copydoc PDMUSBHLP::pfnThreadCreate
+ */
+DECLINLINE(int) PDMUsbHlpThreadCreate(PPDMUSBINS pUsbIns, PPPDMTHREAD ppThread, void *pvUser, PFNPDMTHREADUSB pfnThread,
+                                         PFNPDMTHREADWAKEUPUSB pfnWakeup, size_t cbStack, RTTHREADTYPE enmType, const char *pszName)
+{
+    return pUsbIns->pHlpR3->pfnThreadCreate(pUsbIns, ppThread, pvUser, pfnThread, pfnWakeup, cbStack, enmType, pszName);
+}
+
+
+/**
  * @copydoc PDMUSBHLP::pfnSetAsyncNotification
  */
Index: /trunk/src/VBox/VMM/VMMR3/PDMUsb.cpp
===================================================================
--- /trunk/src/VBox/VMM/VMMR3/PDMUsb.cpp	(revision 37858)
+++ /trunk/src/VBox/VMM/VMMR3/PDMUsb.cpp	(revision 37859)
@@ -1367,4 +1367,21 @@
 
 
+/** @interface_method_impl{PDMUSBHLP,pfnThreadCreate} */
+static DECLCALLBACK(int) pdmR3UsbHlp_ThreadCreate(PPDMUSBINS pUsbIns, PPPDMTHREAD ppThread, void *pvUser, PFNPDMTHREADUSB pfnThread,
+                                                  PFNPDMTHREADWAKEUPUSB pfnWakeup, size_t cbStack, RTTHREADTYPE enmType, const char *pszName)
+{
+    PDMDEV_ASSERT_DEVINS(pUsbIns);
+    VM_ASSERT_EMT(pUsbIns->Internal.s.pVM);
+    LogFlow(("pdmR3UsbHlp_ThreadCreate: caller='%s'/%d: ppThread=%p pvUser=%p pfnThread=%p pfnWakeup=%p cbStack=%#zx enmType=%d pszName=%p:{%s}\n",
+             pUsbIns->pReg->szName, pUsbIns->iInstance, ppThread, pvUser, pfnThread, pfnWakeup, cbStack, enmType, pszName, pszName));
+
+    int rc = pdmR3ThreadCreateUsb(pUsbIns->Internal.s.pVM, pUsbIns, ppThread, pvUser, pfnThread, pfnWakeup, cbStack, enmType, pszName);
+
+    LogFlow(("pdmR3UsbHlp_ThreadCreate: caller='%s'/%d: returns %Rrc *ppThread=%RTthrd\n", pUsbIns->pReg->szName, pUsbIns->iInstance,
+             rc, *ppThread));
+    return rc;
+}
+
+
 /** @interface_method_impl{PDMUSBHLP,pfnSetAsyncNotification} */
 static DECLCALLBACK(int) pdmR3UsbHlp_SetAsyncNotification(PPDMUSBINS pUsbIns, PFNPDMUSBASYNCNOTIFY pfnAsyncNotify)
@@ -1439,4 +1456,5 @@
     pdmR3UsbHlp_VMSetRuntimeErrorV,
     pdmR3UsbHlp_VMState,
+    pdmR3UsbHlp_ThreadCreate,
     pdmR3UsbHlp_SetAsyncNotification,
     pdmR3UsbHlp_AsyncNotificationCompleted,