Changeset 72459 in vbox for trunk/src/VBox/Devices

Timestamp:

Jun 6, 2018 8:17:43 AM (7 years ago)

Author:

vboxsync

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

122941

Message:

Dev/VirtioNet: (​bugref:8651) TX thread is used instead of TX timer.

File:

• trunk/src/VBox/Devices/Network/DevVirtioNet.cpp (modified) (8 diffs)

trunk/src/VBox/Devices/Network/DevVirtioNet.cpp

@@ -64 +64 @@
 #endif /* VBOX_DEVICE_STRUCT_TESTCASE */
 
-
-#define VNET_TX_DELAY           150   /**< 150 microseconds */
+/*
+ * Commenting out VNET_TX_DELAY enables async transmission in a dedicated thread.
+ * When VNET_TX_DELAY is defined, a timer handler does the job. 
+ */
+//#define VNET_TX_DELAY           150   /**< 150 microseconds */
 #define VNET_MAX_FRAME_SIZE     65535 + 18  /**< Max IP packet size + Ethernet header with VLAN tag */
 #define VNET_MAC_FILTER_LEN     32
@@ -154 +157 @@
     uint32_t                u32MaxDiff;
     uint64_t                u64NanoTS;
-#endif /* VNET_TX_DELAY */
+#else /* !VNET_TX_DELAY */
+    /** The support driver session handle. */
+    R3R0PTRTYPE(PSUPDRVSESSION)     pSupDrvSession;
+    /** The event semaphore TX thread waits on. */
+    SUPSEMEVENT                     hTxEvent;
+    R3PTRTYPE(PPDMTHREAD)           pTxThread;
+#endif /* !VNET_TX_DELAY */
 
     /** Indicates transmission in progress -- only one thread is allowed. */
@@ -1476 +1485 @@
 }
 
+inline int vnetCreateTxThreadAndEvent(PPDMDEVINS pDevIns, PVNETSTATE pThis)
+{
+    RT_NOREF(pDevIns, pThis);
+    return VINF_SUCCESS;
+}
+
+inline void vnetDestroyTxThreadAndEvent(PVNETSTATE pThis)
+{
+    RT_NOREF(pThis);
+}
 #else /* !VNET_TX_DELAY */
 
+static DECLCALLBACK(int) vnetTxThread(PPDMDEVINS pDevIns, PPDMTHREAD pThread)
+{
+    RT_NOREF(pDevIns);
+    PVNETSTATE pThis = (PVNETSTATE)pThread->pvUser;
+    int rc = VINF_SUCCESS;
+
+    if (pThread->enmState == PDMTHREADSTATE_INITIALIZING)
+        return VINF_SUCCESS;
+
+    while (pThread->enmState == PDMTHREADSTATE_RUNNING)
+    {
+        rc = SUPSemEventWaitNoResume(pThis->pSupDrvSession, pThis->hTxEvent, RT_INDEFINITE_WAIT);
+        if (RT_UNLIKELY(pThread->enmState != PDMTHREADSTATE_RUNNING))
+            break;
+        vnetTransmitPendingPackets(pThis, pThis->pTxQueue, false /*fOnWorkerThread*/); // @todo: shouldn't it be true instead?
+        Log(("vnetTxThread: enable kicking and get to sleep\n"));
+        vringSetNotification(&pThis->VPCI, &pThis->pTxQueue->VRing, true);
+    }
+
+    return rc;
+}
+
+/**
+ * Unblock TX thread so it can respond to a state change.
+ *
+ * @returns VBox status code.
+ * @param   pDevIns     The device instance.
+ * @param   pThread     The send thread.
+ */
+static DECLCALLBACK(int) vnetTxThreadWakeUp(PPDMDEVINS pDevIns, PPDMTHREAD pThread)
+{
+    RT_NOREF(pDevIns);
+    PVNETSTATE pThis = (PVNETSTATE)pThread->pvUser;
+    return SUPSemEventSignal(pThis->pSupDrvSession, pThis->hTxEvent);
+}
+
+static int vnetCreateTxThreadAndEvent(PPDMDEVINS pDevIns, PVNETSTATE pThis)
+{
+    int rc = SUPSemEventCreate(pThis->pSupDrvSession, &pThis->hTxEvent);
+    if (RT_FAILURE(rc))
+        return PDMDevHlpVMSetError(pDevIns, rc, RT_SRC_POS,
+                                   N_("VNET: Failed to create SUP event semaphore"));
+    rc = PDMDevHlpThreadCreate(pDevIns, &pThis->pTxThread, pThis, vnetTxThread,
+                               vnetTxThreadWakeUp, 0, RTTHREADTYPE_IO, INSTANCE(pThis));
+    if (RT_FAILURE(rc))
+        return PDMDevHlpVMSetError(pDevIns, rc, RT_SRC_POS,
+                                   N_("VNET: Failed to create worker thread %s"), INSTANCE(pThis));
+    return VINF_SUCCESS;
+}
+
+static void vnetDestroyTxThreadAndEvent(PVNETSTATE pThis)
+{
+    if (pThis->pTxThread)
+    {
+        int rcThread;
+        /* Destroy the thread. */
+        int rc = PDMR3ThreadDestroy(pThis->pTxThread, &rcThread);
+        if (RT_FAILURE(rc) || RT_FAILURE(rcThread))
+            AssertMsgFailed(("%s Failed to destroy async IO thread rc=%Rrc rcThread=%Rrc\n", __FUNCTION__, rc, rcThread));
+        pThis->pTxThread = NULL;
+    }
+    if (pThis->hTxEvent != NIL_SUPSEMEVENT)
+    {
+        SUPSemEventClose(pThis->pSupDrvSession, pThis->hTxEvent);
+        pThis->hTxEvent = NIL_SUPSEMEVENT;
+    }
+}
+
 static DECLCALLBACK(void) vnetQueueTransmit(void *pvState, PVQUEUE pQueue)
 {
     PVNETSTATE pThis = (PVNETSTATE)pvState;
 
-    vnetTransmitPendingPackets(pThis, pQueue, false /*fOnWorkerThread*/);
+    Log(("vnetQueueTransmit: disable kicking and wake up TX thread\n"));
+    vringSetNotification(&pThis->VPCI, &pQueue->VRing, false);
+    SUPSemEventSignal(pThis->pSupDrvSession, pThis->hTxEvent);
 }
 
@@ -1919 +2008 @@
     }
 
+    vnetDestroyTxThreadAndEvent(pThis);
     /*
      * Zero some important members.
@@ -1966 +2056 @@
         AssertMsgStmt(pThis->pDrv, ("Failed to obtain the PDMINETWORKUP interface!\n"),
                       rc = VERR_PDM_MISSING_INTERFACE_BELOW);
+
+        vnetCreateTxThreadAndEvent(pDevIns, pThis);
     }
     else if (   rc == VERR_PDM_NO_ATTACHED_DRIVER
@@ -2032 +2124 @@
     PVNETSTATE pThis = PDMINS_2_DATA(pDevIns, PVNETSTATE);
 
+#ifdef VNET_TX_DELAY
     LogRel(("TxTimer stats (avg/min/max): %7d usec %7d usec %7d usec\n",
             pThis->u32AvgDiff, pThis->u32MinDiff, pThis->u32MaxDiff));
+#endif /* VNET_TX_DELAY */
     Log(("%s Destroying instance\n", INSTANCE(pThis)));
     if (pThis->hEventMoreRxDescAvail != NIL_RTSEMEVENT)
@@ -2163 +2257 @@
         return rc;
 
-#ifdef VNET_TX_DELAY
+#ifndef VNET_TX_DELAY
+    pThis->pSupDrvSession = PDMDevHlpGetSupDrvSession(pDevIns);
+    pThis->hTxEvent       = NIL_SUPSEMEVENT;
+    pThis->pTxThread      = NULL;
+#else /* VNET_TX_DELAY */
     /* Create Transmit Delay Timer */
     rc = PDMDevHlpTMTimerCreate(pDevIns, TMCLOCK_VIRTUAL, vnetTxTimer, pThis,
@@ -2188 +2286 @@
         AssertMsgReturn(pThis->pDrv, ("Failed to obtain the PDMINETWORKUP interface!\n"),
                         VERR_PDM_MISSING_INTERFACE_BELOW);
+
+        vnetCreateTxThreadAndEvent(pDevIns, pThis);
     }
     else if (   rc == VERR_PDM_NO_ATTACHED_DRIVER