/**
 * Construct a block driver instance.
 *
 * @copydoc FNPDMDRVCONSTRUCT
 */
static DECLCALLBACK(int) drvscsihostConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfg, uint32_t fFlags)
{
    PDRVSCSIHOST pThis = PDMINS_2_DATA(pDrvIns, PDRVSCSIHOST);
    LogFlowFunc(("pDrvIns=%#p pCfg=%#p\n", pDrvIns, pCfg));
    PDMDRV_CHECK_VERSIONS_RETURN(pDrvIns);

    /*
     * Initialize the instance data first because of the destructor.
     */
    pDrvIns->IBase.pfnQueryInterface            = drvscsihostQueryInterface;
    pThis->ISCSIConnector.pfnSCSIRequestSend    = drvscsihostRequestSend;
    pThis->pDrvIns                              = pDrvIns;
    pThis->hDeviceFile                          = NIL_RTFILE;
    pThis->hQueueRequests                       = NIL_RTREQQUEUE;

    /*
     * Read the configuration.
     */
    if (!CFGMR3AreValuesValid(pCfg, "DevicePath\0"))
        return PDMDRV_SET_ERROR(pDrvIns, VERR_PDM_DRVINS_UNKNOWN_CFG_VALUES,
                                N_("Invalid configuration for host scsi access driver"));


    /* Query the SCSI port interface above. */
    pThis->pDevScsiPort = PDMIBASE_QUERY_INTERFACE(pDrvIns->pUpBase, PDMISCSIPORT);
    AssertMsgReturn(pThis->pDevScsiPort, ("Missing SCSI port interface above\n"), VERR_PDM_MISSING_INTERFACE);

    /* Create request queue. */
    int rc = RTReqQueueCreate(&pThis->hQueueRequests);
    AssertMsgReturn(RT_SUCCESS(rc), ("Failed to create request queue rc=%Rrc\n"), rc);

    /* Open the device. */
    rc = CFGMR3QueryStringAlloc(pCfg, "DevicePath", &pThis->pszDevicePath);
    if (RT_FAILURE(rc))
        return PDMDRV_SET_ERROR(pDrvIns, rc,
                                N_("Configuration error: Failed to get the \"DevicePath\" value"));

    rc = RTFileOpen(&pThis->hDeviceFile, pThis->pszDevicePath, RTFILE_O_READWRITE | RTFILE_O_OPEN | RTFILE_O_DENY_NONE);
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                   N_("DrvSCSIHost#%d: Failed to open device '%s'"), pDrvIns->iInstance, pThis->pszDevicePath);

    /* Create I/O thread. */
    rc = PDMDrvHlpThreadCreate(pDrvIns, &pThis->pAsyncIOThread, pThis, drvscsihostAsyncIOLoop,
                               drvscsihostAsyncIOLoopWakeup, 0, RTTHREADTYPE_IO, "SCSI async IO");
    AssertMsgReturn(RT_SUCCESS(rc), ("Failed to create async I/O thread rc=%Rrc\n"), rc);

    return VINF_SUCCESS;
}
/**
 * Construct a char driver instance.
 *
 * @copydoc FNPDMDRVCONSTRUCT
 */
static DECLCALLBACK(int) drvCharConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfg, uint32_t fFlags)
{
    PDRVCHAR pThis = PDMINS_2_DATA(pDrvIns, PDRVCHAR);
    LogFlow(("%s: iInstance=%d\n", __FUNCTION__, pDrvIns->iInstance));
    PDMDRV_CHECK_VERSIONS_RETURN(pDrvIns);

    /*
     * Init basic data members and interfaces.
     */
    pThis->fShutdown                        = false;
    pThis->ReceiveThread                    = NIL_RTTHREAD;
    pThis->SendThread                       = NIL_RTTHREAD;
    pThis->SendSem                          = NIL_RTSEMEVENT;
    /* IBase. */
    pDrvIns->IBase.pfnQueryInterface        = drvCharQueryInterface;
    /* ICharConnector. */
    pThis->ICharConnector.pfnWrite          = drvCharWrite;
    pThis->ICharConnector.pfnSetParameters  = drvCharSetParameters;
    pThis->ICharConnector.pfnSetModemLines  = drvCharSetModemLines;
    pThis->ICharConnector.pfnSetBreak       = drvCharSetBreak;

    /*
     * Get the ICharPort interface of the above driver/device.
     */
    pThis->pDrvCharPort = PDMIBASE_QUERY_INTERFACE(pDrvIns->pUpBase, PDMICHARPORT);
    if (!pThis->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 = PDMDrvHlpAttach(pDrvIns, fFlags, &pBase);
    if (RT_FAILURE(rc))
        return rc; /* Don't call PDMDrvHlpVMSetError here as we assume that the driver already set an appropriate error */
    pThis->pDrvStream = PDMIBASE_QUERY_INTERFACE(pBase, PDMISTREAM);
    if (!pThis->pDrvStream)
        return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_MISSING_INTERFACE_BELOW, RT_SRC_POS, N_("Char#%d has no stream interface below"), pDrvIns->iInstance);

    /*
     * Don't start the receive thread if the driver doesn't support reading
     */
    if (pThis->pDrvStream->pfnRead)
    {
        rc = RTThreadCreate(&pThis->ReceiveThread, drvCharReceiveLoop, (void *)pThis, 0,
                            RTTHREADTYPE_IO, RTTHREADFLAGS_WAITABLE, "CharRecv");
        if (RT_FAILURE(rc))
            return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d cannot create receive thread"), pDrvIns->iInstance);
    }

    rc = RTSemEventCreate(&pThis->SendSem);
    AssertRCReturn(rc, rc);

    rc = RTThreadCreate(&pThis->SendThread, drvCharSendLoop, (void *)pThis, 0,
                        RTTHREADTYPE_IO, RTTHREADFLAGS_WAITABLE, "CharSend");
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d cannot create send thread"), pDrvIns->iInstance);


    PDMDrvHlpSTAMRegisterF(pDrvIns, &pThis->StatBytesWritten,    STAMTYPE_COUNTER, STAMVISIBILITY_USED, STAMUNIT_BYTES, "Nr of bytes written",         "/Devices/Char%d/Written", pDrvIns->iInstance);
    PDMDrvHlpSTAMRegisterF(pDrvIns, &pThis->StatBytesRead,       STAMTYPE_COUNTER, STAMVISIBILITY_USED, STAMUNIT_BYTES, "Nr of bytes read",            "/Devices/Char%d/Read", pDrvIns->iInstance);

    return VINF_SUCCESS;
}
/**
 * Construct a host parallel driver instance.
 *
 * @copydoc FNPDMDRVCONSTRUCT
 */
static DECLCALLBACK(int) drvHostParallelConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfg, uint32_t fFlags)
{
    PDRVHOSTPARALLEL pThis = PDMINS_2_DATA(pDrvIns, PDRVHOSTPARALLEL);
    LogFlowFunc(("iInstance=%d\n", pDrvIns->iInstance));

    PDMDRV_CHECK_VERSIONS_RETURN(pDrvIns);

    /*
     * Init basic data members and interfaces.
     *
     * Must be done before returning any failure because we've got a destructor.
     */
    pThis->hFileDevice  = NIL_RTFILE;
#ifndef VBOX_WITH_WIN_PARPORT_SUP
    pThis->hWakeupPipeR = NIL_RTPIPE;
    pThis->hWakeupPipeW = NIL_RTPIPE;
#else
    pThis->hWinFileDevice = NIL_RTFILE;
#endif

    pThis->pDrvInsR3                                = pDrvIns;
#ifdef VBOX_WITH_DRVINTNET_IN_R0
    pThis->pDrvInsR0                                = PDMDRVINS_2_R0PTR(pDrvIns);
#endif

    /* IBase. */
    pDrvIns->IBase.pfnQueryInterface                  = drvHostParallelQueryInterface;
    /* IHostParallelConnector. */
    pThis->IHostParallelConnectorR3.pfnWrite            = drvHostParallelWrite;
    pThis->IHostParallelConnectorR3.pfnRead             = drvHostParallelRead;
    pThis->IHostParallelConnectorR3.pfnSetPortDirection = drvHostParallelSetPortDirection;
    pThis->IHostParallelConnectorR3.pfnWriteControl     = drvHostParallelWriteControl;
    pThis->IHostParallelConnectorR3.pfnReadControl      = drvHostParallelReadControl;
    pThis->IHostParallelConnectorR3.pfnReadStatus       = drvHostParallelReadStatus;

    /*
     * Validate the config.
     */
    if (!CFGMR3AreValuesValid(pCfg, "DevicePath\0"))
        return PDMDRV_SET_ERROR(pDrvIns, VERR_PDM_DRVINS_UNKNOWN_CFG_VALUES,
                                N_("Unknown host parallel configuration option, only supports DevicePath"));

    /*
     * Query configuration.
     */
    /* Device */
    int rc = CFGMR3QueryStringAlloc(pCfg, "DevicePath", &pThis->pszDevicePath);
    if (RT_FAILURE(rc))
    {
        AssertMsgFailed(("Configuration error: query for \"DevicePath\" string returned %Rra.\n", rc));
        return rc;
    }

    /*
     * Open the device
     */
    rc = RTFileOpen(&pThis->hFileDevice, pThis->pszDevicePath, RTFILE_O_READWRITE | RTFILE_O_OPEN | RTFILE_O_DENY_NONE);
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Parallel#%d could not open '%s'"),
                                   pDrvIns->iInstance, pThis->pszDevicePath);

#ifndef VBOX_WITH_WIN_PARPORT_SUP
    /*
     * Try to get exclusive access to parallel port
     */
    rc = ioctl(RTFileToNative(pThis->hFileDevice), PPEXCL);
    if (rc < 0)
        return PDMDrvHlpVMSetError(pDrvIns, RTErrConvertFromErrno(errno), RT_SRC_POS,
                                   N_("Parallel#%d could not get exclusive access for parallel port '%s'"
                                      "Be sure that no other process or driver accesses this port"),
                                   pDrvIns->iInstance, pThis->pszDevicePath);

    /*
     * Claim the parallel port
     */
    rc = ioctl(RTFileToNative(pThis->hFileDevice), PPCLAIM);
    if (rc < 0)
        return PDMDrvHlpVMSetError(pDrvIns, RTErrConvertFromErrno(errno), RT_SRC_POS,
                                   N_("Parallel#%d could not claim parallel port '%s'"
                                      "Be sure that no other process or driver accesses this port"),
                                   pDrvIns->iInstance, pThis->pszDevicePath);

    /*
     * Get the IHostParallelPort interface of the above driver/device.
     */
    pThis->pDrvHostParallelPort = PDMIBASE_QUERY_INTERFACE(pDrvIns->pUpBase, PDMIHOSTPARALLELPORT);
    if (!pThis->pDrvHostParallelPort)
        return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_MISSING_INTERFACE_ABOVE, RT_SRC_POS, N_("Parallel#%d has no parallel port interface above"),
                                   pDrvIns->iInstance);

    /*
     * Create wakeup pipe.
     */
    rc = RTPipeCreate(&pThis->hWakeupPipeR, &pThis->hWakeupPipeW, 0 /*fFlags*/);
    AssertRCReturn(rc, rc);

    /*
     * Start in SPP mode.
     */
    pThis->enmModeCur = PDM_PARALLEL_PORT_MODE_INVALID;
    rc = drvHostParallelSetMode(pThis, PDM_PARALLEL_PORT_MODE_SPP);
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("HostParallel#%d cannot change mode of parallel mode to SPP"), pDrvIns->iInstance);

    /*
     * Start waiting for interrupts.
     */
    rc = PDMDrvHlpThreadCreate(pDrvIns, &pThis->pMonitorThread, pThis, drvHostParallelMonitorThread, drvHostParallelWakeupMonitorThread, 0,
                               RTTHREADTYPE_IO, "ParMon");
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("HostParallel#%d cannot create monitor thread"), pDrvIns->iInstance);

#else /* VBOX_WITH_WIN_PARPORT_SUP */
    pThis->fParportAvail     = false;
    pThis->u32LptAddr        = 0;
    pThis->u32LptAddrControl = 0;
    pThis->u32LptAddrStatus  = 0;
    rc = drvWinHostGetparportAddr(pThis);

    /* If we have the char port availabe use it , else I am not getting exclusive access to parallel port.
       Read and write will be done only if addresses are available
    */
    if (pThis->szParportName)
    {
        rc = RTFileOpen(&pThis->hWinFileDevice, (char *)pThis->szParportName,
                        RTFILE_O_READWRITE | RTFILE_O_OPEN | RTFILE_O_DENY_NONE);
    }
#endif
    return VINF_SUCCESS;
}
/**
 * Construct a disk integrity driver instance.
 *
 * @copydoc FNPDMDRVCONSTRUCT
 */
static DECLCALLBACK(int) drvdiskintConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfg, uint32_t fFlags)
{
    int rc = VINF_SUCCESS;
    PDRVDISKINTEGRITY pThis = PDMINS_2_DATA(pDrvIns, PDRVDISKINTEGRITY);
    LogFlow(("drvdiskintConstruct: iInstance=%d\n", pDrvIns->iInstance));
    PDMDRV_CHECK_VERSIONS_RETURN(pDrvIns);

    /*
     * Validate configuration.
     */
    if (!CFGMR3AreValuesValid(pCfg, "CheckConsistency\0"
                                    "TraceRequests\0"
                                    "CheckIntervalMs\0"
                                    "ExpireIntervalMs\0"
                                    "CheckDoubleCompletions\0"
                                    "HistorySize\0"
                                    "IoLog\0"))
        return VERR_PDM_DRVINS_UNKNOWN_CFG_VALUES;

    rc = CFGMR3QueryBoolDef(pCfg, "CheckConsistency", &pThis->fCheckConsistency, false);
    AssertRC(rc);
    rc = CFGMR3QueryBoolDef(pCfg, "TraceRequests", &pThis->fTraceRequests, false);
    AssertRC(rc);
    rc = CFGMR3QueryU32Def(pCfg, "CheckIntervalMs", &pThis->uCheckIntervalMs, 5000); /* 5 seconds */
    AssertRC(rc);
    rc = CFGMR3QueryU32Def(pCfg, "ExpireIntervalMs", &pThis->uExpireIntervalMs, 20000); /* 20 seconds */
    AssertRC(rc);
    rc = CFGMR3QueryBoolDef(pCfg, "CheckDoubleCompletions", &pThis->fCheckDoubleCompletion, false);
    AssertRC(rc);
    rc = CFGMR3QueryU32Def(pCfg, "HistorySize", &pThis->cEntries, 512);
    AssertRC(rc);

    char *pszIoLogFilename = NULL;
    rc = CFGMR3QueryStringAlloc(pCfg, "IoLog", &pszIoLogFilename);
    Assert(RT_SUCCESS(rc) || rc == VERR_CFGM_VALUE_NOT_FOUND);

    /*
     * Initialize most of the data members.
     */
    pThis->pDrvIns                       = pDrvIns;

    /* IBase. */
    pDrvIns->IBase.pfnQueryInterface     = drvdiskintQueryInterface;

    /* IMedia */
    pThis->IMedia.pfnRead                = drvdiskintRead;
    pThis->IMedia.pfnWrite               = drvdiskintWrite;
    pThis->IMedia.pfnFlush               = drvdiskintFlush;
    pThis->IMedia.pfnGetSize             = drvdiskintGetSize;
    pThis->IMedia.pfnIsReadOnly          = drvdiskintIsReadOnly;
    pThis->IMedia.pfnBiosGetPCHSGeometry = drvdiskintBiosGetPCHSGeometry;
    pThis->IMedia.pfnBiosSetPCHSGeometry = drvdiskintBiosSetPCHSGeometry;
    pThis->IMedia.pfnBiosGetLCHSGeometry = drvdiskintBiosGetLCHSGeometry;
    pThis->IMedia.pfnBiosSetLCHSGeometry = drvdiskintBiosSetLCHSGeometry;
    pThis->IMedia.pfnGetUuid             = drvdiskintGetUuid;

    /* IMediaAsync */
    pThis->IMediaAsync.pfnStartRead      = drvdiskintStartRead;
    pThis->IMediaAsync.pfnStartWrite     = drvdiskintStartWrite;
    pThis->IMediaAsync.pfnStartFlush     = drvdiskintStartFlush;

    /* IMediaAsyncPort. */
    pThis->IMediaAsyncPort.pfnTransferCompleteNotify  = drvdiskintAsyncTransferCompleteNotify;

    /* IMediaPort. */
    pThis->IMediaPort.pfnQueryDeviceLocation = drvdiskintQueryDeviceLocation;

    /* Query the media port interface above us. */
    pThis->pDrvMediaPort = PDMIBASE_QUERY_INTERFACE(pDrvIns->pUpBase, PDMIMEDIAPORT);
    if (!pThis->pDrvMediaPort)
        return PDMDRV_SET_ERROR(pDrvIns, VERR_PDM_MISSING_INTERFACE_BELOW,
                                N_("No media port inrerface above"));

    /* Try to attach async media port interface above.*/
    pThis->pDrvMediaAsyncPort = PDMIBASE_QUERY_INTERFACE(pDrvIns->pUpBase, PDMIMEDIAASYNCPORT);

    /*
     * Try attach driver below and query it's media interface.
     */
    PPDMIBASE pBase;
    rc = PDMDrvHlpAttach(pDrvIns, fFlags, &pBase);
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                   N_("Failed to attach driver below us! %Rrc"), rc);

    pThis->pDrvMedia = PDMIBASE_QUERY_INTERFACE(pBase, PDMIMEDIA);
    if (!pThis->pDrvMedia)
        return PDMDRV_SET_ERROR(pDrvIns, VERR_PDM_MISSING_INTERFACE_BELOW,
                                N_("No media or async media interface below"));

    pThis->pDrvMediaAsync = PDMIBASE_QUERY_INTERFACE(pBase, PDMIMEDIAASYNC);

    if (pThis->pDrvMedia->pfnDiscard)
        pThis->IMedia.pfnDiscard = drvdiskintDiscard;
    if (   pThis->pDrvMediaAsync
        && pThis->pDrvMediaAsync->pfnStartDiscard)
        pThis->IMediaAsync.pfnStartDiscard = drvdiskintStartDiscard;

    if (pThis->fCheckConsistency)
    {
        /* Create the AVL tree. */
        pThis->pTreeSegments = (PAVLRFOFFTREE)RTMemAllocZ(sizeof(AVLRFOFFTREE));
        if (!pThis->pTreeSegments)
            rc = VERR_NO_MEMORY;
    }

    if (pThis->fTraceRequests)
    {
        for (unsigned i = 0; i < RT_ELEMENTS(pThis->apReqActive); i++)
        {
            pThis->apReqActive[i].pIoReq  = NULL;
            pThis->apReqActive[i].tsStart = 0;
        }

        pThis->iNextFreeSlot = 0;

        /* Init event semaphore. */
        rc = RTSemEventCreate(&pThis->SemEvent);
        AssertRC(rc);
        pThis->fRunning = true;
        rc = RTThreadCreate(&pThis->hThread, drvdiskIntIoReqExpiredCheck, pThis,
                            0, RTTHREADTYPE_INFREQUENT_POLLER, 0, "DiskIntegrity");
        AssertRC(rc);
    }

    if (pThis->fCheckDoubleCompletion)
    {
        pThis->iEntry = 0;
        pThis->papIoReq = (PDRVDISKAIOREQ *)RTMemAllocZ(pThis->cEntries * sizeof(PDRVDISKAIOREQ));
        AssertPtr(pThis->papIoReq);
    }

    if (pszIoLogFilename)
    {
        rc = VDDbgIoLogCreate(&pThis->hIoLogger, pszIoLogFilename, VDDBG_IOLOG_LOG_DATA);
        MMR3HeapFree(pszIoLogFilename);
    }

    return rc;
}
/**
 * Construct a block driver instance.
 *
 * @copydoc FNPDMDRVCONSTRUCT
 */
static DECLCALLBACK(int) drvscsiConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfg, uint32_t fFlags)
{
    int rc = VINF_SUCCESS;
    PDRVSCSI pThis = PDMINS_2_DATA(pDrvIns, PDRVSCSI);
    LogFlowFunc(("pDrvIns=%#p pCfg=%#p\n", pDrvIns, pCfg));
    PDMDRV_CHECK_VERSIONS_RETURN(pDrvIns);

    /*
     * Initialize the instance data.
     */
    pThis->pDrvIns                              = pDrvIns;
    pThis->ISCSIConnector.pfnSCSIRequestSend    = drvscsiRequestSend;
    pThis->ISCSIConnector.pfnQueryLUNType       = drvscsiQueryLUNType;

    pDrvIns->IBase.pfnQueryInterface            = drvscsiQueryInterface;

    pThis->IMountNotify.pfnMountNotify          = drvscsiMountNotify;
    pThis->IMountNotify.pfnUnmountNotify        = drvscsiUnmountNotify;
    pThis->IPort.pfnQueryDeviceLocation         = drvscsiQueryDeviceLocation;
    pThis->IPortAsync.pfnTransferCompleteNotify = drvscsiTransferCompleteNotify;
    pThis->hQueueRequests                       = NIL_RTREQQUEUE;

    /* Query the SCSI port interface above. */
    pThis->pDevScsiPort = PDMIBASE_QUERY_INTERFACE(pDrvIns->pUpBase, PDMISCSIPORT);
    AssertMsgReturn(pThis->pDevScsiPort, ("Missing SCSI port interface above\n"), VERR_PDM_MISSING_INTERFACE);

    /* Query the optional LED interface above. */
    pThis->pLedPort = PDMIBASE_QUERY_INTERFACE(pDrvIns->pUpBase, PDMILEDPORTS);
    if (pThis->pLedPort != NULL)
    {
        /* Get The Led. */
        rc = pThis->pLedPort->pfnQueryStatusLed(pThis->pLedPort, 0, &pThis->pLed);
        if (RT_FAILURE(rc))
            pThis->pLed = &pThis->Led;
    }
    else
        pThis->pLed = &pThis->Led;

    /*
     * Validate and read configuration.
     */
    if (!CFGMR3AreValuesValid(pCfg, "NonRotationalMedium\0Readonly\0"))
        return PDMDRV_SET_ERROR(pDrvIns, VERR_PDM_DEVINS_UNKNOWN_CFG_VALUES,
                                N_("SCSI configuration error: unknown option specified"));

    rc = CFGMR3QueryBoolDef(pCfg, "NonRotationalMedium", &pThis->fNonRotational, false);
    if (RT_FAILURE(rc))
        return PDMDRV_SET_ERROR(pDrvIns, rc,
                    N_("SCSI configuration error: failed to read \"NonRotationalMedium\" as boolean"));

    rc = CFGMR3QueryBoolDef(pCfg, "Readonly", &pThis->fReadonly, false);
    if (RT_FAILURE(rc))
        return PDMDRV_SET_ERROR(pDrvIns, rc,
                                N_("SCSI configuration error: failed to read \"Readonly\" as boolean"));

    /*
     * Try attach driver below and query it's block interface.
     */
    rc = PDMDrvHlpAttach(pDrvIns, fFlags, &pThis->pDrvBase);
    AssertMsgReturn(RT_SUCCESS(rc), ("Attaching driver below failed rc=%Rrc\n", rc), rc);

    /*
     * Query the block and blockbios interfaces.
     */
    pThis->pDrvBlock = PDMIBASE_QUERY_INTERFACE(pThis->pDrvBase, PDMIBLOCK);
    if (!pThis->pDrvBlock)
    {
        AssertMsgFailed(("Configuration error: No block interface!\n"));
        return VERR_PDM_MISSING_INTERFACE;
    }
    pThis->pDrvBlockBios = PDMIBASE_QUERY_INTERFACE(pThis->pDrvBase, PDMIBLOCKBIOS);
    if (!pThis->pDrvBlockBios)
    {
        AssertMsgFailed(("Configuration error: No block BIOS interface!\n"));
        return VERR_PDM_MISSING_INTERFACE;
    }

    pThis->pDrvMount = PDMIBASE_QUERY_INTERFACE(pThis->pDrvBase, PDMIMOUNT);

    /* Try to get the optional async block interface. */
    pThis->pDrvBlockAsync = PDMIBASE_QUERY_INTERFACE(pThis->pDrvBase, PDMIBLOCKASYNC);

    PDMBLOCKTYPE enmType = pThis->pDrvBlock->pfnGetType(pThis->pDrvBlock);
    VSCSILUNTYPE enmLunType;
    switch (enmType)
    {
    case PDMBLOCKTYPE_HARD_DISK:
        enmLunType = VSCSILUNTYPE_SBC;
        break;
    case PDMBLOCKTYPE_CDROM:
    case PDMBLOCKTYPE_DVD:
        enmLunType = VSCSILUNTYPE_MMC;
        break;
    default:
        return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_UNSUPPORTED_BLOCK_TYPE, RT_SRC_POS,
                                   N_("Only hard disks and CD/DVD-ROMs are currently supported as SCSI devices (enmType=%d)"),
                                   enmType);
    }
    if (    (   enmType == PDMBLOCKTYPE_DVD
             || enmType == PDMBLOCKTYPE_CDROM)
        &&  !pThis->pDrvMount)
    {
        AssertMsgFailed(("Internal error: cdrom without a mountable interface\n"));
        return VERR_INTERNAL_ERROR;
    }

    /* Create VSCSI device and LUN. */
    pThis->VScsiIoCallbacks.pfnVScsiLunMediumGetSize       = drvscsiGetSize;
    pThis->VScsiIoCallbacks.pfnVScsiLunMediumGetSectorSize = drvscsiGetSectorSize;
    pThis->VScsiIoCallbacks.pfnVScsiLunReqTransferEnqueue  = drvscsiReqTransferEnqueue;
    pThis->VScsiIoCallbacks.pfnVScsiLunGetFeatureFlags     = drvscsiGetFeatureFlags;
    pThis->VScsiIoCallbacks.pfnVScsiLunMediumSetLock       = drvscsiSetLock;

    rc = VSCSIDeviceCreate(&pThis->hVScsiDevice, drvscsiVScsiReqCompleted, pThis);
    AssertMsgReturn(RT_SUCCESS(rc), ("Failed to create VSCSI device rc=%Rrc\n"), rc);
    rc = VSCSILunCreate(&pThis->hVScsiLun, enmLunType, &pThis->VScsiIoCallbacks,
                        pThis);
    AssertMsgReturn(RT_SUCCESS(rc), ("Failed to create VSCSI LUN rc=%Rrc\n"), rc);
    rc = VSCSIDeviceLunAttach(pThis->hVScsiDevice, pThis->hVScsiLun, 0);
    AssertMsgReturn(RT_SUCCESS(rc), ("Failed to attached the LUN to the SCSI device\n"), rc);

    //@todo: This is a very hacky way of telling the LUN whether a medium was mounted.
    // The mount/unmount interface doesn't work in a very sensible manner!
    if (pThis->pDrvMount)
    {
        if (pThis->pDrvBlock->pfnGetSize(pThis->pDrvBlock))
        {
            rc = VINF_SUCCESS; VSCSILunMountNotify(pThis->hVScsiLun);
            AssertMsgReturn(RT_SUCCESS(rc), ("Failed to notify the LUN of media being mounted\n"), rc);
        }
        else
        {
            rc = VINF_SUCCESS; VSCSILunUnmountNotify(pThis->hVScsiLun);
            AssertMsgReturn(RT_SUCCESS(rc), ("Failed to notify the LUN of media being unmounted\n"), rc);
        }
    }

    /* Register statistics counter. */
    /** @todo aeichner: Find a way to put the instance number of the attached
     * controller device when we support more than one controller of the same type.
     * At the moment we have the 0 hardcoded. */
    PDMDrvHlpSTAMRegisterF(pDrvIns, &pThis->StatBytesRead, STAMTYPE_COUNTER, STAMVISIBILITY_ALWAYS, STAMUNIT_BYTES,
                            "Amount of data read.", "/Devices/SCSI0/%d/ReadBytes", pDrvIns->iInstance);
    PDMDrvHlpSTAMRegisterF(pDrvIns, &pThis->StatBytesWritten, STAMTYPE_COUNTER, STAMVISIBILITY_ALWAYS, STAMUNIT_BYTES,
                            "Amount of data written.", "/Devices/SCSI0/%d/WrittenBytes", pDrvIns->iInstance);

    pThis->StatIoDepth = 0;

    PDMDrvHlpSTAMRegisterF(pDrvIns, (void *)&pThis->StatIoDepth, STAMTYPE_U32, STAMVISIBILITY_ALWAYS, STAMUNIT_COUNT,
                            "Number of active tasks.", "/Devices/SCSI0/%d/IoDepth", pDrvIns->iInstance);

    if (!pThis->pDrvBlockAsync)
    {
        /* Create request queue. */
        rc = RTReqQueueCreate(&pThis->hQueueRequests);
        AssertMsgReturn(RT_SUCCESS(rc), ("Failed to create request queue rc=%Rrc\n"), rc);
        /* Create I/O thread. */
        rc = PDMDrvHlpThreadCreate(pDrvIns, &pThis->pAsyncIOThread, pThis, drvscsiAsyncIOLoop,
                                   drvscsiAsyncIOLoopWakeup, 0, RTTHREADTYPE_IO, "SCSI async IO");
        AssertMsgReturn(RT_SUCCESS(rc), ("Failed to create async I/O thread rc=%Rrc\n"), rc);

        LogRel(("SCSI#%d: using normal I/O\n", pDrvIns->iInstance));
    }
    else
        LogRel(("SCSI#%d: using async I/O\n", pDrvIns->iInstance));

    if (   pThis->pDrvBlock->pfnDiscard
        || (   pThis->pDrvBlockAsync
            && pThis->pDrvBlockAsync->pfnStartDiscard))
        LogRel(("SCSI#%d: Enabled UNMAP support\n"));

    return VINF_SUCCESS;
}
/**
 * Construct a TCP socket stream driver instance.
 *
 * @copydoc FNPDMDRVCONSTRUCT
 */
static DECLCALLBACK(int) drvTCPConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfg, uint32_t fFlags)
{
    RT_NOREF(fFlags);
    PDMDRV_CHECK_VERSIONS_RETURN(pDrvIns);
    PDRVTCP pThis = PDMINS_2_DATA(pDrvIns, PDRVTCP);

    /*
     * Init the static parts.
     */
    pThis->pDrvIns                      = pDrvIns;
    pThis->pszLocation                  = NULL;
    pThis->fIsServer                    = false;

    pThis->hTcpServ                     = NULL;
    pThis->hTcpSock                     = NIL_RTSOCKET;

    pThis->hPollSet                     = NIL_RTPOLLSET;
    pThis->hPipeWakeR                   = NIL_RTPIPE;
    pThis->hPipeWakeW                   = NIL_RTPIPE;
    pThis->fTcpSockInPollSet            = false;

    pThis->ListenThread                 = NIL_RTTHREAD;
    pThis->fShutdown                    = false;
    /* IBase */
    pDrvIns->IBase.pfnQueryInterface    = drvTCPQueryInterface;
    /* IStream */
    pThis->IStream.pfnPoll              = drvTcpPoll;
    pThis->IStream.pfnPollInterrupt     = drvTcpPollInterrupt;
    pThis->IStream.pfnRead              = drvTcpRead;
    pThis->IStream.pfnWrite             = drvTcpWrite;

    /*
     * Validate and read the configuration.
     */
    PDMDRV_VALIDATE_CONFIG_RETURN(pDrvIns, "Location|IsServer", "");

    int rc = CFGMR3QueryStringAlloc(pCfg, "Location", &pThis->pszLocation);
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                   N_("Configuration error: querying \"Location\" resulted in %Rrc"), rc);
    rc = CFGMR3QueryBool(pCfg, "IsServer", &pThis->fIsServer);
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                   N_("Configuration error: querying \"IsServer\" resulted in %Rrc"), rc);

    rc = RTPipeCreate(&pThis->hPipeWakeR, &pThis->hPipeWakeW, 0 /* fFlags */);
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                   N_("DrvTCP#%d: Failed to create wake pipe"), pDrvIns->iInstance);

    rc = RTPollSetCreate(&pThis->hPollSet);
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                   N_("DrvTCP#%d: Failed to create poll set"), pDrvIns->iInstance);

    rc = RTPollSetAddPipe(pThis->hPollSet, pThis->hPipeWakeR,
                            RTPOLL_EVT_READ | RTPOLL_EVT_ERROR,
                            DRVTCP_POLLSET_ID_WAKEUP);
    if (RT_FAILURE(rc))
        return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                   N_("DrvTCP#%d failed to add wakeup pipe for %s to poll set"),
                                   pDrvIns->iInstance, pThis->pszLocation);

    /*
     * Create/Open the socket.
     */
    if (pThis->fIsServer)
    {
        uint32_t uPort = 0;
        rc = RTStrToUInt32Ex(pThis->pszLocation, NULL, 10, &uPort);
        if (RT_FAILURE(rc))
            return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                       N_("DrvTCP#%d: The port part of the location is not a numerical value"),
                                       pDrvIns->iInstance);

        /** @todo Allow binding to distinct interfaces. */
        rc = RTTcpServerCreateEx(NULL, uPort, &pThis->hTcpServ);
        if (RT_FAILURE(rc))
            return PDMDrvHlpVMSetError(pDrvIns, rc,  RT_SRC_POS,
                                       N_("DrvTCP#%d failed to create server socket"), pDrvIns->iInstance);

        rc = RTThreadCreate(&pThis->ListenThread, drvTCPListenLoop, (void *)pThis, 0,
                            RTTHREADTYPE_IO, RTTHREADFLAGS_WAITABLE, "DrvTCPStream");
        if (RT_FAILURE(rc))
            return PDMDrvHlpVMSetError(pDrvIns, rc,  RT_SRC_POS,
                                       N_("DrvTCP#%d failed to create listening thread"), pDrvIns->iInstance);
    }
    else
    {
        char *pszPort = strchr(pThis->pszLocation, ':');
        if (!pszPort)
            return PDMDrvHlpVMSetError(pDrvIns, VERR_NOT_FOUND, RT_SRC_POS,
                                       N_("DrvTCP#%d: The location misses the port to connect to"),
                                       pDrvIns->iInstance);

        *pszPort = '\0'; /* Overwrite temporarily to avoid copying the hostname into a temporary buffer. */
        uint32_t uPort = 0;
        rc = RTStrToUInt32Ex(pszPort + 1, NULL, 10, &uPort);
        if (RT_FAILURE(rc))
            return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                       N_("DrvTCP#%d: The port part of the location is not a numerical value"),
                                       pDrvIns->iInstance);

        rc = RTTcpClientConnect(pThis->pszLocation, uPort, &pThis->hTcpSock);
        *pszPort = ':'; /* Restore delimiter before checking the status. */
        if (RT_FAILURE(rc))
            return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                       N_("DrvTCP#%d failed to connect to socket %s"),
                                       pDrvIns->iInstance, pThis->pszLocation);

        rc = RTPollSetAddSocket(pThis->hPollSet, pThis->hTcpSock,
                                RTPOLL_EVT_READ | RTPOLL_EVT_WRITE | RTPOLL_EVT_ERROR,
                                DRVTCP_POLLSET_ID_SOCKET);
        if (RT_FAILURE(rc))
            return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS,
                                       N_("DrvTCP#%d failed to add socket for %s to poll set"),
                                       pDrvIns->iInstance, pThis->pszLocation);

        pThis->fTcpSockInPollSet = true;
    }

    LogRel(("DrvTCP: %s, %s\n", pThis->pszLocation, pThis->fIsServer ? "server" : "client"));
    return VINF_SUCCESS;
}