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Diffstat (limited to 'src/VBox/Additions/common/VBoxService/VBoxServiceTimeSync.cpp')
| -rw-r--r-- | src/VBox/Additions/common/VBoxService/VBoxServiceTimeSync.cpp | 815 |
1 files changed, 815 insertions, 0 deletions
diff --git a/src/VBox/Additions/common/VBoxService/VBoxServiceTimeSync.cpp b/src/VBox/Additions/common/VBoxService/VBoxServiceTimeSync.cpp new file mode 100644 index 00000000..ca2ea383 --- /dev/null +++ b/src/VBox/Additions/common/VBoxService/VBoxServiceTimeSync.cpp @@ -0,0 +1,815 @@ +/* $Id: VBoxServiceTimeSync.cpp $ */ +/** @file + * VBoxService - Guest Additions TimeSync Service. + */ + +/* + * Copyright (C) 2007-2019 Oracle Corporation + * + * 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 (GPL) 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. + */ + + +/** @page pg_vgsvc_timesync VBoxService - The Time Sync Service + * + * The time sync subservice synchronizes the guest OS walltime with the host. + * + * The time sync service plays along with the Time Manager (TM) in the VMM + * to keep the guest time accurate using the host machine as a reference. + * Communication is facilitated by VMMDev. TM will try its best to make sure + * all timer ticks get delivered so that there isn't normally any need to + * adjust the guest time. + * + * There are three normal (= acceptable) cases: + * -# When the service starts up. This is because ticks and such might + * be lost during VM and OS startup. (Need to figure out exactly why!) + * -# When the TM is unable to deliver all the ticks and swallows a + * backlog of ticks. The threshold for this is configurable with + * a default of 60 seconds. + * -# The time is adjusted on the host. This can be caused manually by + * the user or by some time sync daemon (NTP, LAN server, etc.). + * + * There are a number of very odd case where adjusting is needed. Here + * are some of them: + * -# Timer device emulation inaccuracies (like rounding). + * -# Inaccuracies in time source VirtualBox uses. + * -# The Guest and/or Host OS doesn't perform proper time keeping. This + * can come about as a result of OS and/or hardware issues. + * + * The TM is our source for the host time and will make adjustments for + * current timer delivery lag. The simplistic approach taken by TM is to + * adjust the host time by the current guest timer delivery lag, meaning that + * if the guest is behind 1 second with PIT/RTC/++ ticks, this should be + * reflected in the guest wall time as well. + * + * Now, there is any amount of trouble we can cause by changing the time. + * Most applications probably use the wall time when they need to measure + * things. A walltime that is being juggled about every so often, even if just + * a little bit, could occasionally upset these measurements by for instance + * yielding negative results. + * + * This bottom line here is that the time sync service isn't really supposed + * to do anything and will try avoid having to do anything when possible. + * + * The implementation uses the latency it takes to query host time as the + * absolute maximum precision to avoid messing up under timer tick catchup + * and/or heavy host/guest load. (Rationale is that a *lot* of stuff may + * happen on our way back from ring-3 and TM/VMMDev since we're taking the + * route thru the inner EM loop with its force flag processing.) + * + * But this latency has to be measured from our perspective, which means it + * could just as easily come out as 0. (OS/2 and Windows guests only update + * the current time when the timer ticks for instance.) The good thing is + * that this isn't really a problem since we won't ever do anything unless + * the drift is noticeable. + * + * It now boils down to these three (configuration) factors: + * -# g_cMsTimeSyncMinAdjust - The minimum drift we will ever bother with. + * -# g_TimeSyncLatencyFactor - The factor we multiply the latency by to + * calculate the dynamic minimum adjust factor. + * -# g_cMsTimeSyncMaxLatency - When to start discarding the data as utterly + * useless and take a rest (someone is too busy to give us good data). + * -# g_TimeSyncSetThreshold - The threshold at which we will just set the time + * instead of trying to adjust it (milliseconds). + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#ifdef RT_OS_WINDOWS +# include <iprt/win/windows.h> +#else +# include <unistd.h> +# include <errno.h> +# include <time.h> +# include <sys/time.h> +#endif + +#include <iprt/assert.h> +#include <iprt/string.h> +#include <iprt/semaphore.h> +#include <iprt/time.h> +#include <iprt/thread.h> +#include <VBox/err.h> +#include <VBox/VBoxGuestLib.h> +#include "VBoxServiceInternal.h" +#include "VBoxServiceUtils.h" + + +/********************************************************************************************************************************* +* Global Variables * +*********************************************************************************************************************************/ +/** The timesync interval (milliseconds). */ +static uint32_t g_TimeSyncInterval = 0; +/** + * @see pg_vgsvc_timesync + * + * @remark OS/2: There is either a 1 second resolution on the DosSetDateTime + * API or a bug in my settimeofday implementation. Thus, don't + * bother unless there is at least a 1 second drift. + */ +#ifdef RT_OS_OS2 +static uint32_t g_cMsTimeSyncMinAdjust = 1000; +#else +static uint32_t g_cMsTimeSyncMinAdjust = 100; +#endif +/** @see pg_vgsvc_timesync */ +static uint32_t g_TimeSyncLatencyFactor = 8; +/** @see pg_vgsvc_timesync */ +static uint32_t g_cMsTimeSyncMaxLatency = 250; +/** @see pg_vgsvc_timesync */ +static uint32_t g_TimeSyncSetThreshold = 20*60*1000; +/** Whether the next adjustment should just set the time instead of trying to + * adjust it. This is used to implement --timesync-set-start. + * For purposes of setting the kernel timezone, OS/2 always starts with this. */ +#ifdef RT_OS_OS2 +static bool volatile g_fTimeSyncSetOnStart = true; +#else +static bool volatile g_fTimeSyncSetOnStart = false; +#endif +/** Whether to set the time when the VM was restored. */ +static bool g_fTimeSyncSetOnRestore = true; +/** The logging verbosity level. + * This uses the global verbosity level by default. */ +static uint32_t g_cTimeSyncVerbosity = 0; + +/** Current error count. Used to decide when to bitch and when not to. */ +static uint32_t g_cTimeSyncErrors = 0; + +/** The semaphore we're blocking on. */ +static RTSEMEVENTMULTI g_TimeSyncEvent = NIL_RTSEMEVENTMULTI; + +/** The VM session ID. Changes whenever the VM is restored or reset. */ +static uint64_t g_idTimeSyncSession; + +#ifdef RT_OS_WINDOWS +/** Process token. */ +static HANDLE g_hTokenProcess = NULL; +/** Old token privileges. */ +static TOKEN_PRIVILEGES g_TkOldPrivileges; +/** Backup values for time adjustment. */ +static DWORD g_dwWinTimeAdjustment; +static DWORD g_dwWinTimeIncrement; +static BOOL g_bWinTimeAdjustmentDisabled; +#endif + + +/** + * @interface_method_impl{VBOXSERVICE,pfnPreInit} + */ +static DECLCALLBACK(int) vgsvcTimeSyncPreInit(void) +{ + /* Use global verbosity as default. */ + g_cTimeSyncVerbosity = g_cVerbosity; + +#ifdef VBOX_WITH_GUEST_PROPS + /** @todo Merge this function with vgsvcTimeSyncOption() to generalize + * the "command line args override guest property values" behavior. */ + + /* + * Read the service options from the VM's guest properties. + * Note that these options can be overridden by the command line options later. + */ + uint32_t uGuestPropSvcClientID; + int rc = VbglR3GuestPropConnect(&uGuestPropSvcClientID); + if (RT_FAILURE(rc)) + { + if (rc == VERR_HGCM_SERVICE_NOT_FOUND) /* Host service is not available. */ + { + VGSvcVerbose(0, "VMInfo: Guest property service is not available, skipping\n"); + rc = VINF_SUCCESS; + } + else + VGSvcError("Failed to connect to the guest property service! Error: %Rrc\n", rc); + } + else + { + rc = VGSvcReadPropUInt32(uGuestPropSvcClientID, "/VirtualBox/GuestAdd/VBoxService/--timesync-interval", + &g_TimeSyncInterval, 50, UINT32_MAX - 1); + if ( RT_SUCCESS(rc) + || rc == VERR_NOT_FOUND) + rc = VGSvcReadPropUInt32(uGuestPropSvcClientID, "/VirtualBox/GuestAdd/VBoxService/--timesync-min-adjust", + &g_cMsTimeSyncMinAdjust, 0, 3600000); + if ( RT_SUCCESS(rc) + || rc == VERR_NOT_FOUND) + rc = VGSvcReadPropUInt32(uGuestPropSvcClientID, "/VirtualBox/GuestAdd/VBoxService/--timesync-latency-factor", + &g_TimeSyncLatencyFactor, 1, 1024); + if ( RT_SUCCESS(rc) + || rc == VERR_NOT_FOUND) + rc = VGSvcReadPropUInt32(uGuestPropSvcClientID, "/VirtualBox/GuestAdd/VBoxService/--timesync-max-latency", + &g_cMsTimeSyncMaxLatency, 1, 3600000); + if ( RT_SUCCESS(rc) + || rc == VERR_NOT_FOUND) + rc = VGSvcReadPropUInt32(uGuestPropSvcClientID, "/VirtualBox/GuestAdd/VBoxService/--timesync-set-threshold", + &g_TimeSyncSetThreshold, 0, 7*24*60*60*1000 /* a week */); + if ( RT_SUCCESS(rc) + || rc == VERR_NOT_FOUND) + { + rc = VGSvcCheckPropExist(uGuestPropSvcClientID, "/VirtualBox/GuestAdd/VBoxService/--timesync-set-start"); + if (RT_SUCCESS(rc)) + g_fTimeSyncSetOnStart = true; + } + if ( RT_SUCCESS(rc) + || rc == VERR_NOT_FOUND) + { + rc = VGSvcCheckPropExist(uGuestPropSvcClientID, "/VirtualBox/GuestAdd/VBoxService/--timesync-no-set-start"); + if (RT_SUCCESS(rc)) + g_fTimeSyncSetOnStart = false; + } + if ( RT_SUCCESS(rc) + || rc == VERR_NOT_FOUND) + { + rc = VGSvcCheckPropExist(uGuestPropSvcClientID, "/VirtualBox/GuestAdd/VBoxService/--timesync-set-on-restore"); + if (RT_SUCCESS(rc)) + g_fTimeSyncSetOnRestore = true; + } + if ( RT_SUCCESS(rc) + || rc == VERR_NOT_FOUND) + { + rc = VGSvcCheckPropExist(uGuestPropSvcClientID, "/VirtualBox/GuestAdd/VBoxService/--timesync-no-set-on-restore"); + if (RT_SUCCESS(rc)) + g_fTimeSyncSetOnRestore = false; + } + if ( RT_SUCCESS(rc) + || rc == VERR_NOT_FOUND) + { + uint32_t uValue; + rc = VGSvcReadPropUInt32(uGuestPropSvcClientID, "/VirtualBox/GuestAdd/VBoxService/--timesync-verbosity", + &uValue, 0 /*uMin*/, 255 /*uMax*/); + if (RT_SUCCESS(rc)) + g_cTimeSyncVerbosity = uValue; + } + VbglR3GuestPropDisconnect(uGuestPropSvcClientID); + } + + if (rc == VERR_NOT_FOUND) /* If a value is not found, don't be sad! */ + rc = VINF_SUCCESS; + return rc; +#else + /* Nothing to do here yet. */ + return VINF_SUCCESS; +#endif +} + + +/** + * Displays a verbose message based on the currently + * set timesync verbosity level. + * + * @param iLevel Minimum log level required to display this message. + * @param pszFormat The message text. + * @param ... Format arguments. + */ +static void vgsvcTimeSyncLog(unsigned iLevel, const char *pszFormat, ...) +{ + if (iLevel <= g_cTimeSyncVerbosity) + { + va_list va; + va_start(va, pszFormat); + VGSvcLogV(pszFormat, va); + va_end(va); + } +} + + +/** + * @interface_method_impl{VBOXSERVICE,pfnOption} + */ +static DECLCALLBACK(int) vgsvcTimeSyncOption(const char **ppszShort, int argc, char **argv, int *pi) +{ + int rc = VINF_SUCCESS; + if (ppszShort) + rc = -1 ;/* no short options */ + else if (!strcmp(argv[*pi], "--timesync-interval")) + rc = VGSvcArgUInt32(argc, argv, "", pi, &g_TimeSyncInterval, 50, UINT32_MAX - 1); + else if (!strcmp(argv[*pi], "--timesync-min-adjust")) + rc = VGSvcArgUInt32(argc, argv, "", pi, &g_cMsTimeSyncMinAdjust, 0, 3600000); + else if (!strcmp(argv[*pi], "--timesync-latency-factor")) + rc = VGSvcArgUInt32(argc, argv, "", pi, &g_TimeSyncLatencyFactor, 1, 1024); + else if (!strcmp(argv[*pi], "--timesync-max-latency")) + rc = VGSvcArgUInt32(argc, argv, "", pi, &g_cMsTimeSyncMaxLatency, 1, 3600000); + else if (!strcmp(argv[*pi], "--timesync-set-threshold")) + rc = VGSvcArgUInt32(argc, argv, "", pi, &g_TimeSyncSetThreshold, 0, 7*24*60*60*1000); /* a week */ + else if (!strcmp(argv[*pi], "--timesync-set-start")) + g_fTimeSyncSetOnStart = true; + else if (!strcmp(argv[*pi], "--timesync-no-set-start")) + g_fTimeSyncSetOnStart = false; + else if (!strcmp(argv[*pi], "--timesync-set-on-restore")) + g_fTimeSyncSetOnRestore = true; + else if (!strcmp(argv[*pi], "--timesync-no-set-on-restore")) + g_fTimeSyncSetOnRestore = false; + else if (!strcmp(argv[*pi], "--timesync-verbosity")) + rc = VGSvcArgUInt32(argc, argv, "", pi, &g_cTimeSyncVerbosity, 0 /*uMin*/, 255 /*uMax*/); + else + rc = -1; + + return rc; +} + + +/** + * @interface_method_impl{VBOXSERVICE,pfnInit} + */ +static DECLCALLBACK(int) vgsvcTimeSyncInit(void) +{ + /* + * If not specified, find the right interval default. + * Then create the event sem to block on. + */ + if (!g_TimeSyncInterval) + g_TimeSyncInterval = g_DefaultInterval * 1000; + if (!g_TimeSyncInterval) + g_TimeSyncInterval = 10 * 1000; + + VbglR3GetSessionId(&g_idTimeSyncSession); + /* The status code is ignored as this information is not available with VBox < 3.2.10. */ + + int rc = RTSemEventMultiCreate(&g_TimeSyncEvent); + AssertRC(rc); +#ifdef RT_OS_WINDOWS + if (RT_SUCCESS(rc)) + { + /* + * Adjust privileges of this process so we can make system time adjustments. + */ + if (OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &g_hTokenProcess)) + { + TOKEN_PRIVILEGES tkPriv; + RT_ZERO(tkPriv); + tkPriv.PrivilegeCount = 1; + tkPriv.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED; + if (LookupPrivilegeValue(NULL, SE_SYSTEMTIME_NAME, &tkPriv.Privileges[0].Luid)) + { + DWORD cbRet = sizeof(g_TkOldPrivileges); + if (AdjustTokenPrivileges(g_hTokenProcess, FALSE, &tkPriv, sizeof(TOKEN_PRIVILEGES), &g_TkOldPrivileges, &cbRet)) + rc = VINF_SUCCESS; + else + { + DWORD dwErr = GetLastError(); + rc = RTErrConvertFromWin32(dwErr); + VGSvcError("vgsvcTimeSyncInit: Adjusting token privileges (SE_SYSTEMTIME_NAME) failed with status code %u/%Rrc!\n", + dwErr, rc); + } + } + else + { + DWORD dwErr = GetLastError(); + rc = RTErrConvertFromWin32(dwErr); + VGSvcError("vgsvcTimeSyncInit: Looking up token privileges (SE_SYSTEMTIME_NAME) failed with status code %u/%Rrc!\n", + dwErr, rc); + } + if (RT_FAILURE(rc)) + { + CloseHandle(g_hTokenProcess); + g_hTokenProcess = NULL; + } + } + else + { + DWORD dwErr = GetLastError(); + rc = RTErrConvertFromWin32(dwErr); + VGSvcError("vgsvcTimeSyncInit: Opening process token (SE_SYSTEMTIME_NAME) failed with status code %u/%Rrc!\n", + dwErr, rc); + g_hTokenProcess = NULL; + } + } + + if (g_pfnGetSystemTimeAdjustment) + { + if (g_pfnGetSystemTimeAdjustment(&g_dwWinTimeAdjustment, &g_dwWinTimeIncrement, &g_bWinTimeAdjustmentDisabled)) + vgsvcTimeSyncLog(0, "vgsvcTimeSyncInit: Initially %ld (100ns) units per %ld (100 ns) units interval, disabled=%d\n", + g_dwWinTimeAdjustment, g_dwWinTimeIncrement, g_bWinTimeAdjustmentDisabled ? 1 : 0); + else + { + DWORD dwErr = GetLastError(); + rc = RTErrConvertFromWin32(dwErr); + VGSvcError("vgsvcTimeSyncInit: Could not get time adjustment values! Last error: %ld!\n", dwErr); + } + } +#endif /* RT_OS_WINDOWS */ + + return rc; +} + + +/** + * Try adjusting the time using adjtime or similar. + * + * @returns true on success, false on failure. + * + * @param pDrift The time adjustment. + */ +static bool vgsvcTimeSyncAdjust(PCRTTIMESPEC pDrift) +{ +#ifdef RT_OS_WINDOWS +/** @todo r=bird: g_hTokenProcess cannot be NULL here. + * vgsvcTimeSyncInit will fail and the service will not be started with + * it being NULL. vgsvcTimeSyncInit OTOH will *NOT* be called until the + * service thread has terminated. If anything + * else is the case, there is buggy code somewhere.*/ + if (g_hTokenProcess == NULL) /* Is the token already closed when shutting down? */ + return false; + + /* The API appeared in NT 3.50. */ + if ( !g_pfnSetSystemTimeAdjustment + || !g_pfnGetSystemTimeAdjustment) + return false; + + DWORD dwWinTimeAdjustment, dwWinNewTimeAdjustment, dwWinTimeIncrement; + BOOL fWinTimeAdjustmentDisabled; + if (g_pfnGetSystemTimeAdjustment(&dwWinTimeAdjustment, &dwWinTimeIncrement, &fWinTimeAdjustmentDisabled)) + { + DWORD dwDiffMax = g_dwWinTimeAdjustment * 0.50; + DWORD dwDiffNew = dwWinTimeAdjustment * 0.10; + + if (RTTimeSpecGetMilli(pDrift) > 0) + { + dwWinNewTimeAdjustment = dwWinTimeAdjustment + dwDiffNew; + if (dwWinNewTimeAdjustment > (g_dwWinTimeAdjustment + dwDiffMax)) + { + dwWinNewTimeAdjustment = g_dwWinTimeAdjustment + dwDiffMax; + dwDiffNew = dwDiffMax; + } + } + else + { + dwWinNewTimeAdjustment = dwWinTimeAdjustment - dwDiffNew; + if (dwWinNewTimeAdjustment < (g_dwWinTimeAdjustment - dwDiffMax)) + { + dwWinNewTimeAdjustment = g_dwWinTimeAdjustment - dwDiffMax; + dwDiffNew = dwDiffMax; + } + } + + vgsvcTimeSyncLog(3, "vgsvcTimeSyncAdjust: Drift=%lldms\n", RTTimeSpecGetMilli(pDrift)); + vgsvcTimeSyncLog(3, "vgsvcTimeSyncAdjust: OrgTA=%ld, CurTA=%ld, NewTA=%ld, DiffNew=%ld, DiffMax=%ld\n", + g_dwWinTimeAdjustment, dwWinTimeAdjustment, dwWinNewTimeAdjustment, dwDiffNew, dwDiffMax); + if (g_pfnSetSystemTimeAdjustment(dwWinNewTimeAdjustment, FALSE /* Periodic adjustments enabled. */)) + { + g_cTimeSyncErrors = 0; + return true; + } + + if (g_cTimeSyncErrors++ < 10) + VGSvcError("vgsvcTimeSyncAdjust: SetSystemTimeAdjustment failed, error=%u\n", GetLastError()); + } + else if (g_cTimeSyncErrors++ < 10) + VGSvcError("vgsvcTimeSyncAdjust: GetSystemTimeAdjustment failed, error=%ld\n", GetLastError()); + +#elif defined(RT_OS_OS2) || defined(RT_OS_HAIKU) + /* No API for doing gradual time adjustments. */ + +#else /* PORTME */ + /* + * Try using adjtime(), most unix-like systems have this. + */ + struct timeval tv; + RTTimeSpecGetTimeval(pDrift, &tv); + if (adjtime(&tv, NULL) == 0) + { + vgsvcTimeSyncLog(1, "vgsvcTimeSyncAdjust: adjtime by %RDtimespec\n", pDrift); + g_cTimeSyncErrors = 0; + return true; + } +#endif + + /* failed */ + return false; +} + + +/** + * Cancels any pending time adjustment. + * + * Called when we've caught up and before calls to vgsvcTimeSyncSet. + */ +static void vgsvcTimeSyncCancelAdjust(void) +{ +#ifdef RT_OS_WINDOWS +/** @todo r=bird: g_hTokenProcess cannot be NULL here. See argumentation in + * vgsvcTimeSyncAdjust. */ + if (g_hTokenProcess == NULL) /* No process token (anymore)? */ + return; + if (!g_pfnSetSystemTimeAdjustment) + return; + if (g_pfnSetSystemTimeAdjustment(0, TRUE /* Periodic adjustments disabled. */)) + vgsvcTimeSyncLog(5, "vgsvcTimeSyncCancelAdjust: Windows Time Adjustment is now disabled.\n"); + else if (g_cTimeSyncErrors++ < 10) + VGSvcError("vgsvcTimeSyncCancelAdjust: SetSystemTimeAdjustment(,disable) failed, error=%u\n", GetLastError()); +#endif /* !RT_OS_WINDOWS */ +} + + +/** + * Set the wall clock to compensate for drift. + * + * @returns true on success, false on failure. + * + * @param pDrift The time adjustment. + */ +static void vgsvcTimeSyncSet(PCRTTIMESPEC pDrift) +{ + /* + * Query the current time, adjust it by adding the drift and set it. + */ + RTTIMESPEC NewGuestTime; + int rc = RTTimeSet(RTTimeSpecAdd(RTTimeNow(&NewGuestTime), pDrift)); + if (RT_SUCCESS(rc)) + { + /* Succeeded - reset the error count and log the change. */ + g_cTimeSyncErrors = 0; + + if (g_cTimeSyncVerbosity >= 1) + { + char sz[64]; + RTTIME Time; + vgsvcTimeSyncLog(1, "time set to %s\n", RTTimeToString(RTTimeExplode(&Time, &NewGuestTime), sz, sizeof(sz))); +#ifdef DEBUG + RTTIMESPEC Tmp; + vgsvcTimeSyncLog(3, " now %s\n", RTTimeToString(RTTimeExplode(&Time, RTTimeNow(&Tmp)), sz, sizeof(sz))); +#endif + } + } + else if (g_cTimeSyncErrors++ < 10) + VGSvcError("vgsvcTimeSyncSet: RTTimeSet(%RDtimespec) failed: %Rrc\n", &NewGuestTime, rc); +} + + +/** + * @interface_method_impl{VBOXSERVICE,pfnWorker} + */ +DECLCALLBACK(int) vgsvcTimeSyncWorker(bool volatile *pfShutdown) +{ + RTTIME Time; + int rc = VINF_SUCCESS; + + /* + * Tell the control thread that it can continue spawning services. + */ + RTThreadUserSignal(RTThreadSelf()); + + /* + * Initialize the last host and guest times to prevent log message. + * We also track whether we set the time in the previous loop. + */ + RTTIMESPEC HostLast; + if (RT_FAILURE(VbglR3GetHostTime(&HostLast))) + RTTimeSpecSetNano(&HostLast, 0); + RTTIMESPEC GuestLast; + RTTimeNow(&GuestLast); + bool fSetTimeLastLoop = false; + + /* + * The Work Loop. + */ + for (;;) + { + /* + * Try to get a reliable time reading. + */ + int cTries = 3; + do + { + /* + * Query the session id (first to keep lantency low) and the time. + */ + uint64_t idNewSession = g_idTimeSyncSession; + if (g_fTimeSyncSetOnRestore) + VbglR3GetSessionId(&idNewSession); + + RTTIMESPEC GuestNow0; + RTTimeNow(&GuestNow0); + + RTTIMESPEC HostNow; + int rc2 = VbglR3GetHostTime(&HostNow); + if (RT_FAILURE(rc2)) + { + if (g_cTimeSyncErrors++ < 10) + VGSvcError("vgsvcTimeSyncWorker: VbglR3GetHostTime failed; rc2=%Rrc\n", rc2); + break; + } + + RTTIMESPEC GuestNow; + RTTimeNow(&GuestNow); + + /* + * Calc latency and check if it's ok. + */ + RTTIMESPEC GuestElapsed = GuestNow; + RTTimeSpecSub(&GuestElapsed, &GuestNow0); + if ((uint32_t)RTTimeSpecGetMilli(&GuestElapsed) < g_cMsTimeSyncMaxLatency) + { + /* + * If we were just restored, set the adjustment threshold to zero to force a resync. + */ + uint32_t TimeSyncSetThreshold = g_TimeSyncSetThreshold; + if ( g_fTimeSyncSetOnRestore + && idNewSession != g_idTimeSyncSession) + { + vgsvcTimeSyncLog(2, "vgsvcTimeSyncWorker: The VM session ID changed, forcing resync.\n"); + g_idTimeSyncSession = idNewSession; + TimeSyncSetThreshold = 0; + } + + /* + * Calculate the adjustment threshold and the current drift. + */ + uint32_t MinAdjust = RTTimeSpecGetMilli(&GuestElapsed) * g_TimeSyncLatencyFactor; + if (MinAdjust < g_cMsTimeSyncMinAdjust) + MinAdjust = g_cMsTimeSyncMinAdjust; + + RTTIMESPEC Drift = HostNow; + RTTimeSpecSub(&Drift, &GuestNow); + if (RTTimeSpecGetMilli(&Drift) < 0) + MinAdjust += g_cMsTimeSyncMinAdjust; /* extra buffer against moving time backwards. */ + + RTTIMESPEC AbsDrift = Drift; + RTTimeSpecAbsolute(&AbsDrift); + + if (g_cTimeSyncVerbosity >= 4) + { + char sz1[64]; + char sz2[64]; + vgsvcTimeSyncLog(4, "vgsvcTimeSyncWorker: Host: %s (MinAdjust: %RU32 ms), Guest: %s => %RDtimespec drift\n", + RTTimeToString(RTTimeExplode(&Time, &HostNow), sz1, sizeof(sz1)), MinAdjust, + RTTimeToString(RTTimeExplode(&Time, &GuestNow), sz2, sizeof(sz2)), &Drift); + } + + bool fSetTimeInThisLoop = false; + uint64_t AbsDriftMilli = RTTimeSpecGetMilli(&AbsDrift); + if ( AbsDriftMilli > MinAdjust + || g_fTimeSyncSetOnStart) + { + /* + * Ok, the drift is above the threshold. + * + * Try a gradual adjustment first, if that fails or the drift is + * too big, fall back on just setting the time. + */ + if ( AbsDriftMilli > TimeSyncSetThreshold + || g_fTimeSyncSetOnStart + || !vgsvcTimeSyncAdjust(&Drift)) + { + vgsvcTimeSyncCancelAdjust(); + vgsvcTimeSyncSet(&Drift); + fSetTimeInThisLoop = true; + } + + /* + * Log radical host time changes. + */ + int64_t cNsHostDelta = RTTimeSpecGetNano(&HostNow) - RTTimeSpecGetNano(&HostLast); + if ((uint64_t)RT_ABS(cNsHostDelta) > RT_NS_1HOUR / 2) + vgsvcTimeSyncLog(0, "vgsvcTimeSyncWorker: Radical host time change: %'RI64ns (HostNow=%RDtimespec HostLast=%RDtimespec)\n", + cNsHostDelta, &HostNow, &HostLast); + } + else + vgsvcTimeSyncCancelAdjust(); + HostLast = HostNow; + + /* + * Log radical guest time changes (we could be the cause of these, mind). + * Note! Right now we don't care about an extra log line after we called + * vgsvcTimeSyncSet. fSetTimeLastLoop helps show it though. + */ + int64_t cNsGuestDelta = RTTimeSpecGetNano(&GuestNow) - RTTimeSpecGetNano(&GuestLast); + if ((uint64_t)RT_ABS(cNsGuestDelta) > RT_NS_1HOUR / 2) + vgsvcTimeSyncLog(0, "vgsvcTimeSyncWorker: Radical guest time change: %'RI64ns (GuestNow=%RDtimespec GuestLast=%RDtimespec fSetTimeLastLoop=%RTbool)\n", + cNsGuestDelta, &GuestNow, &GuestLast, fSetTimeLastLoop); + GuestLast = GuestNow; + fSetTimeLastLoop = fSetTimeInThisLoop; + break; + } + vgsvcTimeSyncLog(3, "vgsvcTimeSyncWorker: %RDtimespec: latency too high (%RDtimespec, max %ums) sleeping 1s\n", + &GuestNow, &GuestElapsed, g_cMsTimeSyncMaxLatency); + RTThreadSleep(1000); + } while (--cTries > 0); + + /* Clear the set-next/set-start flag. */ + g_fTimeSyncSetOnStart = false; + + /* + * Block for a while. + * + * The event semaphore takes care of ignoring interruptions and it + * allows us to implement service wakeup later. + */ + if (*pfShutdown) + break; + int rc2 = RTSemEventMultiWait(g_TimeSyncEvent, g_TimeSyncInterval); + if (*pfShutdown) + break; + if (rc2 != VERR_TIMEOUT && RT_FAILURE(rc2)) + { + VGSvcError("vgsvcTimeSyncWorker: RTSemEventMultiWait failed; rc2=%Rrc\n", rc2); + rc = rc2; + break; + } + } + + vgsvcTimeSyncCancelAdjust(); + return rc; +} + + +/** + * @interface_method_impl{VBOXSERVICE,pfnStop} + */ +static DECLCALLBACK(void) vgsvcTimeSyncStop(void) +{ + if (g_TimeSyncEvent != NIL_RTSEMEVENTMULTI) + RTSemEventMultiSignal(g_TimeSyncEvent); +} + + +/** + * @interface_method_impl{VBOXSERVICE,pfnTerm} + */ +static DECLCALLBACK(void) vgsvcTimeSyncTerm(void) +{ +#ifdef RT_OS_WINDOWS + /* + * Restore the SE_SYSTEMTIME_NAME token privileges (if init succeeded). + */ + if (g_hTokenProcess) + { + if (!AdjustTokenPrivileges(g_hTokenProcess, FALSE, &g_TkOldPrivileges, sizeof(TOKEN_PRIVILEGES), NULL, NULL)) + { + DWORD dwErr = GetLastError(); + VGSvcError("vgsvcTimeSyncTerm: Restoring token privileges (SE_SYSTEMTIME_NAME) failed with code %u!\n", dwErr); + } + CloseHandle(g_hTokenProcess); + g_hTokenProcess = NULL; + } +#endif /* !RT_OS_WINDOWS */ + + if (g_TimeSyncEvent != NIL_RTSEMEVENTMULTI) + { + RTSemEventMultiDestroy(g_TimeSyncEvent); + g_TimeSyncEvent = NIL_RTSEMEVENTMULTI; + } +} + + +/** + * The 'timesync' service description. + */ +VBOXSERVICE g_TimeSync = +{ + /* pszName. */ + "timesync", + /* pszDescription. */ + "Time synchronization", + /* pszUsage. */ + " [--timesync-interval <ms>] [--timesync-min-adjust <ms>]\n" + " [--timesync-latency-factor <x>] [--timesync-max-latency <ms>]\n" + " [--timesync-set-threshold <ms>]\n" + " [--timesync-set-start|--timesync-no-set-start]\n" + " [--timesync-set-on-restore|--timesync-no-set-on-restore]\n" + " [--timesync-verbosity <level>]" + , + /* pszOptions. */ + " --timesync-interval Specifies the interval at which to synchronize the\n" + " time with the host. The default is 10000 ms.\n" + " --timesync-min-adjust The minimum absolute drift value measured in\n" + " milliseconds to make adjustments for.\n" + " The default is 1000 ms on OS/2 and 100 ms elsewhere.\n" + " --timesync-latency-factor\n" + " The factor to multiply the time query latency with\n" + " to calculate the dynamic minimum adjust time.\n" + " The default is 8 times.\n" + " --timesync-max-latency The max host timer query latency to accept.\n" + " The default is 250 ms.\n" + " --timesync-set-threshold\n" + " The absolute drift threshold, given as milliseconds,\n" + " where to start setting the time instead of trying to\n" + " adjust it. The default is 20 min.\n" + " --timesync-set-start, --timesync-no-set-start \n" + " Set the time when starting the time sync service.\n" +#ifdef RT_OS_OS2 + " Default: --timesync-set-start\n" +#else + " Default: --timesync-no-set-start\n" +#endif + " --timesync-set-on-restore, --timesync-no-set-on-restore\n" + " Whether to immediately set the time when the VM is\n" + " restored or not. Default: --timesync-set-on-restore\n" + " --timesync-verbosity Sets the verbosity level. Defaults to service wide\n" + " verbosity level.\n" + , + /* methods */ + vgsvcTimeSyncPreInit, + vgsvcTimeSyncOption, + vgsvcTimeSyncInit, + vgsvcTimeSyncWorker, + vgsvcTimeSyncStop, + vgsvcTimeSyncTerm +}; + |