TMAllCpu.cpp revision 6760140deea97c8cf2157689f2a459ffe15348f8
/* $Id$ */
/** @file
* TM - Timeout Manager, CPU Time, All Contexts.
*/
/*
* 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_TM
#include <VBox/tm.h>
#include "TMInternal.h"
#include <VBox/vm.h>
#include <VBox/sup.h>
#include <VBox/param.h>
#include <VBox/err.h>
#include <iprt/assert.h>
#include <iprt/asm.h>
#include <iprt/log.h>
/**
* Gets the raw cpu tick from current virtual time.
*/
DECLINLINE(uint64_t) tmCpuTickGetRawVirtual(PVM pVM, bool fCheckTimers)
{
uint64_t u64 = TMVirtualSyncGetEx(pVM, fCheckTimers);
if (u64 != TMCLOCK_FREQ_VIRTUAL)
u64 = ASMMultU64ByU32DivByU32(u64, pVM->tm.s.cTSCTicksPerSecond, TMCLOCK_FREQ_VIRTUAL);
return u64;
}
/**
* Resumes the CPU timestamp counter ticking.
*
* @returns VBox status code.
* @param pVM The VM to operate on.
*/
TMDECL(int) TMCpuTickResume(PVM pVM)
{
if (!pVM->tm.s.fTSCTicking)
{
pVM->tm.s.fTSCTicking = true;
if (pVM->tm.s.fTSCVirtualized)
{
if (pVM->tm.s.fTSCUseRealTSC)
pVM->tm.s.u64TSCOffset = ASMReadTSC() - pVM->tm.s.u64TSC;
else
pVM->tm.s.u64TSCOffset = tmCpuTickGetRawVirtual(pVM, false /* don't check for pending timers */)
- pVM->tm.s.u64TSC;
}
return VINF_SUCCESS;
}
AssertFailed();
return VERR_INTERNAL_ERROR;
}
/**
* Pauses the CPU timestamp counter ticking.
*
* @returns VBox status code.
* @param pVM The VM to operate on.
*/
TMDECL(int) TMCpuTickPause(PVM pVM)
{
if (pVM->tm.s.fTSCTicking)
{
pVM->tm.s.u64TSC = TMCpuTickGet(pVM);
pVM->tm.s.fTSCTicking = false;
return VINF_SUCCESS;
}
AssertFailed();
return VERR_INTERNAL_ERROR;
}
/**
* Returns the TSC offset (virtual TSC - host TSC)
*
* @returns TSC ofset
* @param pVM The VM to operate on.
* @todo Remove this when the code has been switched to TMCpuTickCanUseRealTSC.
*/
TMDECL(uint64_t) TMCpuTickGetOffset(PVM pVM)
{
uint64_t u64;
if (RT_LIKELY(pVM->tm.s.fTSCTicking))
{
if (pVM->tm.s.fTSCVirtualized)
{
if (pVM->tm.s.fTSCUseRealTSC)
u64 = ASMReadTSC();
else
u64 = tmCpuTickGetRawVirtual(pVM, false /* don't check for pending timers */);
u64 -= pVM->tm.s.u64TSCOffset;
}
else
u64 = ASMReadTSC();
}
else
u64 = pVM->tm.s.u64TSC;
return u64 - ASMReadTSC();
}
/**
* Checks if AMD-V / VT-x can use an offsetted hardware TSC or not.
*
* @returns true/false accordingly.
* @param pVM The VM handle.
* @param poffRealTSC The offset against the TSC of the current CPU.
* Can be NULL.
* @thread EMT.
*/
TMDECL(bool) TMCpuTickCanUseRealTSC(PVM pVM, uint64_t *poffRealTSC)
{
/*
* We require:
* 1. A fixed TSC, this is checked at init time.
* 2. That the TSC is ticking (we shouldn't be here if it isn't)
* 3. Either that we're using the real TSC as time source or
* a) We don't have any lag to catch up.
* b) The virtual sync clock hasn't been halted by an expired timer.
* c) We're not using warp drive (accelerated virtual guest time).
*/
if ( pVM->tm.s.fMaybeUseOffsettedHostTSC
&& RT_LIKELY(pVM->tm.s.fTSCTicking)
&& ( pVM->tm.s.fTSCUseRealTSC
|| ( !pVM->tm.s.fVirtualSyncCatchUp
&& RT_LIKELY(pVM->tm.s.fVirtualSyncTicking)
&& !pVM->tm.s.fVirtualWarpDrive))
)
{
if (!pVM->tm.s.fTSCUseRealTSC)
{
/* The source is the timer synchronous virtual clock. */
Assert(pVM->tm.s.fTSCVirtualized);
if (poffRealTSC)
{
uint64_t u64Now = tmCpuTickGetRawVirtual(pVM, false /* don't check for pending timers */)
- pVM->tm.s.u64TSCOffset;
/** @todo When we start collecting statistics on how much time we spend executing
* guest code before exiting, we should check this against the next virtual sync
* timer timeout. If it's lower than the avg. length, we should trap rdtsc to increase
* the chance that we'll get interrupted right after the timer expired. */
*poffRealTSC = u64Now - ASMReadTSC();
}
}
else if (poffRealTSC)
{
/* The source is the real TSC. */
if (pVM->tm.s.fTSCVirtualized)
*poffRealTSC = pVM->tm.s.u64TSCOffset;
else
*poffRealTSC = 0;
}
return true;
}
return false;
}
/**
* Read the current CPU timstamp counter.
*
* @returns Gets the CPU tsc.
* @param pVM The VM to operate on.
*/
TMDECL(uint64_t) TMCpuTickGet(PVM pVM)
{
uint64_t u64;
if (RT_LIKELY(pVM->tm.s.fTSCTicking))
{
if (pVM->tm.s.fTSCVirtualized)
{
if (pVM->tm.s.fTSCUseRealTSC)
u64 = ASMReadTSC();
else
u64 = tmCpuTickGetRawVirtual(pVM, true /* check for pending timers */);
u64 -= pVM->tm.s.u64TSCOffset;
}
else
u64 = ASMReadTSC();
}
else
u64 = pVM->tm.s.u64TSC;
return u64;
}
/**
* Sets the current CPU timestamp counter.
*
* @returns VBox status code.
* @param pVM The VM to operate on.
* @param u64Tick The new timestamp value.
*/
TMDECL(int) TMCpuTickSet(PVM pVM, uint64_t u64Tick)
{
Assert(!pVM->tm.s.fTSCTicking);
pVM->tm.s.u64TSC = u64Tick;
return VINF_SUCCESS;
}
/**
* Get the timestamp frequency.
*
* @returns Number of ticks per second.
* @param pVM The VM.
*/
TMDECL(uint64_t) TMCpuTicksPerSecond(PVM pVM)
{
if (pVM->tm.s.fTSCUseRealTSC)
{
uint64_t cTSCTicksPerSecond = SUPGetCpuHzFromGIP(g_pSUPGlobalInfoPage);
if (RT_LIKELY(cTSCTicksPerSecond != ~(uint64_t)0))
return cTSCTicksPerSecond;
}
return pVM->tm.s.cTSCTicksPerSecond;
}