/** @file * * VBox stream I/O devices: * Generic char driver */ /* * Copyright (C) 2006 InnoTek Systemberatung GmbH * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License as published by the Free Software Foundation, * in version 2 as it comes in the "COPYING" file of the VirtualBox OSE * distribution. VirtualBox OSE is distributed in the hope that it will * be useful, but WITHOUT ANY WARRANTY of any kind. * * If you received this file as part of a commercial VirtualBox * distribution, then only the terms of your commercial VirtualBox * license agreement apply instead of the previous paragraph. */ /******************************************************************************* * Header Files * *******************************************************************************/ #define LOG_GROUP LOG_GROUP_DRV_CHAR #include #include #include #include #include #include #include #include "Builtins.h" /** Size of the send fifo queue (in bytes) */ #define CHAR_MAX_SEND_QUEUE 0x80 #define CHAR_MAX_SEND_QUEUE_MASK 0x7f /******************************************************************************* * Structures and Typedefs * *******************************************************************************/ /** * Char driver instance data. */ typedef struct DRVCHAR { /** Pointer to the driver instance structure. */ PPDMDRVINS pDrvIns; /** Pointer to the char port interface of the driver/device above us. */ PPDMICHARPORT pDrvCharPort; /** Pointer to the stream interface of the driver below us. */ PPDMISTREAM pDrvStream; /** Our char interface. */ PDMICHAR IChar; /** Flag to notify the receive thread it should terminate. */ volatile bool fShutdown; /** Receive thread ID. */ RTTHREAD ReceiveThread; /** Send thread ID. */ RTTHREAD SendThread; /** Send event semephore */ RTSEMEVENT SendSem; /** Internal send FIFO queue */ uint8_t aSendQueue[CHAR_MAX_SEND_QUEUE]; uint32_t iSendQueueHead; uint32_t iSendQueueTail; /** Read/write statistics */ STAMCOUNTER StatBytesRead; STAMCOUNTER StatBytesWritten; } DRVCHAR, *PDRVCHAR; /** Converts a pointer to DRVCHAR::IChar to a PDRVCHAR. */ #define PDMICHAR_2_DRVCHAR(pInterface) ( (PDRVCHAR)((uintptr_t)pInterface - RT_OFFSETOF(DRVCHAR, IChar)) ) /* -=-=-=-=- IBase -=-=-=-=- */ /** * Queries an interface to the driver. * * @returns Pointer to interface. * @returns NULL if the interface was not supported by the driver. * @param pInterface Pointer to this interface structure. * @param enmInterface The requested interface identification. */ static DECLCALLBACK(void *) drvCharQueryInterface(PPDMIBASE pInterface, PDMINTERFACE enmInterface) { PPDMDRVINS pDrvIns = PDMIBASE_2_PDMDRV(pInterface); PDRVCHAR pData = PDMINS2DATA(pDrvIns, PDRVCHAR); switch (enmInterface) { case PDMINTERFACE_BASE: return &pDrvIns->IBase; case PDMINTERFACE_CHAR: return &pData->IChar; default: return NULL; } } /* -=-=-=-=- IChar -=-=-=-=- */ /** @copydoc PDMICHAR::pfnWrite */ static DECLCALLBACK(int) drvCharWrite(PPDMICHAR pInterface, const void *pvBuf, size_t cbWrite) { PDRVCHAR pData = PDMICHAR_2_DRVCHAR(pInterface); const char *pBuffer = (const char *)pvBuf; int rc = VINF_SUCCESS; LogFlow(("%s: pvBuf=%#p cbWrite=%d\n", __FUNCTION__, pvBuf, cbWrite)); for (uint32_t i=0;iiSendQueueHead; pData->aSendQueue[idx] = pBuffer[i]; idx = (idx + 1) & CHAR_MAX_SEND_QUEUE_MASK; STAM_COUNTER_INC(&pData->StatBytesWritten); ASMAtomicXchgU32(&pData->iSendQueueHead, idx); } RTSemEventSignal(pData->SendSem); return VINF_SUCCESS; } /* -=-=-=-=- receive thread -=-=-=-=- */ /** * Send thread loop. * * @returns 0 on success. * @param ThreadSelf Thread handle to this thread. * @param pvUser User argument. */ static DECLCALLBACK(int) drvCharSendLoop(RTTHREAD ThreadSelf, void *pvUser) { PDRVCHAR pData = (PDRVCHAR)pvUser; for(;;) { int rc = RTSemEventWait(pData->SendSem, RT_INDEFINITE_WAIT); if (VBOX_FAILURE(rc)) break; /* * Write the character to the attached stream (if present). */ if ( !pData->fShutdown && pData->pDrvStream) { while (pData->iSendQueueTail != pData->iSendQueueHead) { size_t cbProcessed = 1; rc = pData->pDrvStream->pfnWrite(pData->pDrvStream, &pData->aSendQueue[pData->iSendQueueTail], &cbProcessed); if (VBOX_SUCCESS(rc)) { Assert(cbProcessed); pData->iSendQueueTail++; pData->iSendQueueTail &= CHAR_MAX_SEND_QUEUE_MASK; } else if (rc == VERR_TIMEOUT) { /* Normal case, just means that the stream didn't accept a new * character before the timeout elapsed. Just retry. */ rc = VINF_SUCCESS; } else { Log(("Write failed with %Vrc; skipping\n", rc)); break; } } } else break; } pData->SendThread = NIL_RTTHREAD; return VINF_SUCCESS; } /* -=-=-=-=- receive thread -=-=-=-=- */ /** * Receive thread loop. * * @returns 0 on success. * @param ThreadSelf Thread handle to this thread. * @param pvUser User argument. */ static DECLCALLBACK(int) drvCharReceiveLoop(RTTHREAD ThreadSelf, void *pvUser) { PDRVCHAR pData = (PDRVCHAR)pvUser; char aBuffer[256], *pBuffer; size_t cbRemaining, cbProcessed; int rc; cbRemaining = 0; pBuffer = aBuffer; while (!pData->fShutdown) { if (!cbRemaining) { /* Get block of data from stream driver. */ if (pData->pDrvStream) { cbRemaining = sizeof(aBuffer); rc = pData->pDrvStream->pfnRead(pData->pDrvStream, aBuffer, &cbRemaining); AssertRC(rc); } else { cbRemaining = 0; RTThreadSleep(100); } pBuffer = aBuffer; } else { /* Send data to guest. */ cbProcessed = cbRemaining; rc = pData->pDrvCharPort->pfnNotifyRead(pData->pDrvCharPort, pBuffer, &cbProcessed); if (VBOX_SUCCESS(rc)) { Assert(cbProcessed); pBuffer += cbProcessed; cbRemaining -= cbProcessed; STAM_COUNTER_ADD(&pData->StatBytesRead, cbProcessed); } else if (rc == VERR_TIMEOUT) { /* Normal case, just means that the guest didn't accept a new * character before the timeout elapsed. Just retry. */ rc = VINF_SUCCESS; } else AssertRC(rc); } } pData->ReceiveThread = NIL_RTTHREAD; return VINF_SUCCESS; } /* -=-=-=-=- driver interface -=-=-=-=- */ /** * Construct a char driver instance. * * @returns VBox status. * @param pDrvIns The driver instance data. * If the registration structure is needed, * pDrvIns->pDrvReg points to it. * @param pCfgHandle Configuration node handle for the driver. Use this to * obtain the configuration of the driver instance. It's * also found in pDrvIns->pCfgHandle as it's expected to * be used frequently in this function. */ static DECLCALLBACK(int) drvCharConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfgHandle) { PDRVCHAR pData = PDMINS2DATA(pDrvIns, PDRVCHAR); LogFlow(("%s: iInstance=%d\n", __FUNCTION__, pDrvIns->iInstance)); /* * Init basic data members and interfaces. */ pData->ReceiveThread = NIL_RTTHREAD; pData->fShutdown = false; /* IBase. */ pDrvIns->IBase.pfnQueryInterface = drvCharQueryInterface; /* IChar. */ pData->IChar.pfnWrite = drvCharWrite; /* * Get the ICharPort interface of the above driver/device. */ pData->pDrvCharPort = (PPDMICHARPORT)pDrvIns->pUpBase->pfnQueryInterface(pDrvIns->pUpBase, PDMINTERFACE_CHAR_PORT); if (!pData->pDrvCharPort) return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_MISSING_INTERFACE_ABOVE, RT_SRC_POS, N_("Char#%d has no char port interface above"), pDrvIns->iInstance); /* * Attach driver below and query its stream interface. */ PPDMIBASE pBase; int rc = pDrvIns->pDrvHlp->pfnAttach(pDrvIns, &pBase); if (VBOX_FAILURE(rc)) return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d failed to attach driver below"), pDrvIns->iInstance); pData->pDrvStream = (PPDMISTREAM)pBase->pfnQueryInterface(pBase, PDMINTERFACE_STREAM); if (!pData->pDrvStream) return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_MISSING_INTERFACE_BELOW, RT_SRC_POS, N_("Char#%d has no stream interface below"), pDrvIns->iInstance); rc = RTThreadCreate(&pData->ReceiveThread, drvCharReceiveLoop, (void *)pData, 0, RTTHREADTYPE_IO, RTTHREADFLAGS_WAITABLE, "Char Receive"); if (VBOX_FAILURE(rc)) return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d cannot create receive thread"), pDrvIns->iInstance); rc = RTSemEventCreate(&pData->SendSem); AssertRC(rc); rc = RTThreadCreate(&pData->SendThread, drvCharSendLoop, (void *)pData, 0, RTTHREADTYPE_IO, RTTHREADFLAGS_WAITABLE, "Char Send"); if (VBOX_FAILURE(rc)) return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d cannot create send thread"), pDrvIns->iInstance); PDMDrvHlpSTAMRegisterF(pDrvIns, &pData->StatBytesWritten, STAMTYPE_COUNTER, STAMVISIBILITY_USED, STAMUNIT_BYTES, "Nr of bytes written", "/Devices/Char%d/Written", pDrvIns->iInstance); PDMDrvHlpSTAMRegisterF(pDrvIns, &pData->StatBytesRead, STAMTYPE_COUNTER, STAMVISIBILITY_USED, STAMUNIT_BYTES, "Nr of bytes read", "/Devices/Char%d/Read", pDrvIns->iInstance); return VINF_SUCCESS; } /** * Destruct a char driver instance. * * Most VM resources are freed by the VM. This callback is provided so that * any non-VM resources can be freed correctly. * * @param pDrvIns The driver instance data. */ static DECLCALLBACK(void) drvCharDestruct(PPDMDRVINS pDrvIns) { PDRVCHAR pData = PDMINS2DATA(pDrvIns, PDRVCHAR); LogFlow(("%s: iInstance=%d\n", __FUNCTION__, pDrvIns->iInstance)); pData->fShutdown = true; RTThreadWait(pData->ReceiveThread, 1000, NULL); if (pData->ReceiveThread != NIL_RTTHREAD) LogRel(("Char%d: receive thread did not terminate\n", pDrvIns->iInstance)); /* Empty the send queue */ pData->iSendQueueTail = pData->iSendQueueHead = 0; RTSemEventSignal(pData->SendSem); RTSemEventDestroy(pData->SendSem); pData->SendSem = NIL_RTSEMEVENT; RTThreadWait(pData->SendThread, 1000, NULL); if (pData->SendThread != NIL_RTTHREAD) LogRel(("Char%d: send thread did not terminate\n", pDrvIns->iInstance)); } /** * Char driver registration record. */ const PDMDRVREG g_DrvChar = { /* u32Version */ PDM_DRVREG_VERSION, /* szDriverName */ "Char", /* pszDescription */ "Generic char driver.", /* fFlags */ PDM_DRVREG_FLAGS_HOST_BITS_DEFAULT, /* fClass. */ PDM_DRVREG_CLASS_CHAR, /* cMaxInstances */ ~0, /* cbInstance */ sizeof(DRVCHAR), /* pfnConstruct */ drvCharConstruct, /* pfnDestruct */ drvCharDestruct, /* pfnIOCtl */ NULL, /* pfnPowerOn */ NULL, /* pfnReset */ NULL, /* pfnSuspend */ NULL, /* pfnResume */ NULL, /* pfnDetach */ NULL, /** pfnPowerOff */ NULL };