/**
* Resumes the CPU timestamp counter ticking.
*
* @returns VBox status code.
* @param pVM The cross context VM structure.
* @param pVCpu The cross context virtual CPU structure.
* @internal
*/
int tmCpuTickResume(PVM pVM, PVMCPU pVCpu)
{
if (!pVCpu->tm.s.fTSCTicking)
{
pVCpu->tm.s.fTSCTicking = true;
/** @todo Test that pausing and resuming doesn't cause lag! (I.e. that we're
* unpaused before the virtual time and stopped after it. */
switch (pVM->tm.s.enmTSCMode)
{
case TMTSCMODE_REAL_TSC_OFFSET:
pVCpu->tm.s.offTSCRawSrc = SUPReadTsc() - pVCpu->tm.s.u64TSC;
break;
case TMTSCMODE_VIRT_TSC_EMULATED:
case TMTSCMODE_DYNAMIC:
pVCpu->tm.s.offTSCRawSrc = tmCpuTickGetRawVirtual(pVM, false /* don't check for pending timers */)
- pVCpu->tm.s.u64TSC;
break;
case TMTSCMODE_NATIVE_API:
pVCpu->tm.s.offTSCRawSrc = 0; /** @todo ?? */
/* Looks like this is only used by weird modes and MSR TSC writes. We cannot support either on NEM/win. */
break;
default:
AssertFailedReturn(VERR_IPE_NOT_REACHED_DEFAULT_CASE);
}
return VINF_SUCCESS;
}
AssertFailed();
return VERR_TM_TSC_ALREADY_TICKING;
}
/**
* Read the current CPU timestamp counter.
*
* @returns Gets the CPU tsc.
* @param pVCpu The cross context virtual CPU structure.
* @param fCheckTimers Whether to check timers.
*/
DECLINLINE(uint64_t) tmCpuTickGetInternal(PVMCPU pVCpu, bool fCheckTimers)
{
uint64_t u64;
if (RT_LIKELY(pVCpu->tm.s.fTSCTicking))
{
PVM pVM = pVCpu->CTX_SUFF(pVM);
if (pVM->tm.s.enmTSCMode == TMTSCMODE_REAL_TSC_OFFSET)
u64 = SUPReadTsc();
else
u64 = tmCpuTickGetRawVirtual(pVM, fCheckTimers);
u64 -= pVCpu->tm.s.offTSCRawSrc;
/* Always return a value higher than what the guest has already seen. */
if (RT_LIKELY(u64 > pVCpu->tm.s.u64TSCLastSeen))
pVCpu->tm.s.u64TSCLastSeen = u64;
else
{
STAM_COUNTER_INC(&pVM->tm.s.StatTSCUnderflow);
pVCpu->tm.s.u64TSCLastSeen += 64; /** @todo choose a good increment here */
u64 = pVCpu->tm.s.u64TSCLastSeen;
}
}
else
u64 = pVCpu->tm.s.u64TSC;
return u64;
}
/**
* Resumes the CPU timestamp counter ticking.
*
* @returns VINF_SUCCESS or VERR_TM_VIRTUAL_TICKING_IPE (asserted).
* @param pVM The cross context VM structure.
* @param pVCpu The cross context virtual CPU structure.
*/
int tmCpuTickResumeLocked(PVM pVM, PVMCPU pVCpu)
{
if (!pVCpu->tm.s.fTSCTicking)
{
/* TSC must be ticking before calling tmCpuTickGetRawVirtual()! */
pVCpu->tm.s.fTSCTicking = true;
uint32_t c = ASMAtomicIncU32(&pVM->tm.s.cTSCsTicking);
AssertMsgReturn(c <= pVM->cCpus, ("%u vs %u\n", c, pVM->cCpus), VERR_TM_VIRTUAL_TICKING_IPE);
if (c == 1)
{
/* The first VCPU to resume. */
uint64_t offTSCRawSrcOld = pVCpu->tm.s.offTSCRawSrc;
STAM_COUNTER_INC(&pVM->tm.s.StatTSCResume);
/* When resuming, use the TSC value of the last stopped VCPU to avoid the TSC going back. */
if (pVM->tm.s.enmTSCMode == TMTSCMODE_REAL_TSC_OFFSET)
pVCpu->tm.s.offTSCRawSrc = SUPReadTsc() - pVM->tm.s.u64LastPausedTSC;
else
pVCpu->tm.s.offTSCRawSrc = tmCpuTickGetRawVirtual(pVM, false /* don't check for pending timers */)
- pVM->tm.s.u64LastPausedTSC;
/* Calculate the offset for other VCPUs to use. */
pVM->tm.s.offTSCPause = pVCpu->tm.s.offTSCRawSrc - offTSCRawSrcOld;
}
else
{
/* All other VCPUs (if any). */
pVCpu->tm.s.offTSCRawSrc += pVM->tm.s.offTSCPause;
}
}
return VINF_SUCCESS;
}
/**
* Read the current CPU timestamp counter.
*
* @returns Gets the CPU tsc.
* @param pVCpu The cross context virtual CPU structure.
* @param fCheckTimers Whether to check timers.
*/
DECLINLINE(uint64_t) tmCpuTickGetInternal(PVMCPU pVCpu, bool fCheckTimers)
{
uint64_t u64;
if (RT_LIKELY(pVCpu->tm.s.fTSCTicking))
{
PVM pVM = pVCpu->CTX_SUFF(pVM);
switch (pVM->tm.s.enmTSCMode)
{
case TMTSCMODE_REAL_TSC_OFFSET:
u64 = SUPReadTsc();
break;
case TMTSCMODE_VIRT_TSC_EMULATED:
case TMTSCMODE_DYNAMIC:
u64 = tmCpuTickGetRawVirtual(pVM, fCheckTimers);
break;
#ifndef IN_RC
case TMTSCMODE_NATIVE_API:
{
u64 = 0;
int rcNem = NEMHCQueryCpuTick(pVCpu, &u64, NULL);
AssertLogRelRCReturn(rcNem, SUPReadTsc());
break;
}
#endif
default:
AssertFailedBreakStmt(u64 = SUPReadTsc());
}
u64 -= pVCpu->tm.s.offTSCRawSrc;
/* Always return a value higher than what the guest has already seen. */
if (RT_LIKELY(u64 > pVCpu->tm.s.u64TSCLastSeen))
pVCpu->tm.s.u64TSCLastSeen = u64;
else
{
STAM_COUNTER_INC(&pVM->tm.s.StatTSCUnderflow);
pVCpu->tm.s.u64TSCLastSeen += 64; /** @todo choose a good increment here */
u64 = pVCpu->tm.s.u64TSCLastSeen;
}
}
else
u64 = pVCpu->tm.s.u64TSC;
return u64;
}
/**
* Resumes the CPU timestamp counter ticking.
*
* @returns VINF_SUCCESS or VERR_TM_VIRTUAL_TICKING_IPE (asserted).
* @param pVM The cross context VM structure.
* @param pVCpu The cross context virtual CPU structure.
*/
int tmCpuTickResumeLocked(PVM pVM, PVMCPU pVCpu)
{
if (!pVCpu->tm.s.fTSCTicking)
{
/* TSC must be ticking before calling tmCpuTickGetRawVirtual()! */
pVCpu->tm.s.fTSCTicking = true;
uint32_t c = ASMAtomicIncU32(&pVM->tm.s.cTSCsTicking);
AssertMsgReturn(c <= pVM->cCpus, ("%u vs %u\n", c, pVM->cCpus), VERR_TM_VIRTUAL_TICKING_IPE);
if (c == 1)
{
/* The first VCPU to resume. */
uint64_t offTSCRawSrcOld = pVCpu->tm.s.offTSCRawSrc;
STAM_COUNTER_INC(&pVM->tm.s.StatTSCResume);
/* When resuming, use the TSC value of the last stopped VCPU to avoid the TSC going back. */
switch (pVM->tm.s.enmTSCMode)
{
case TMTSCMODE_REAL_TSC_OFFSET:
pVCpu->tm.s.offTSCRawSrc = SUPReadTsc() - pVM->tm.s.u64LastPausedTSC;
break;
case TMTSCMODE_VIRT_TSC_EMULATED:
case TMTSCMODE_DYNAMIC:
pVCpu->tm.s.offTSCRawSrc = tmCpuTickGetRawVirtual(pVM, false /* don't check for pending timers */)
- pVM->tm.s.u64LastPausedTSC;
break;
case TMTSCMODE_NATIVE_API:
{
#ifndef IN_RC
int rc = NEMHCResumeCpuTickOnAll(pVM, pVCpu, pVM->tm.s.u64LastPausedTSC);
AssertRCReturn(rc, rc);
pVCpu->tm.s.offTSCRawSrc = offTSCRawSrcOld = 0;
#else
AssertFailedReturn(VERR_INTERNAL_ERROR_2);
#endif
break;
}
default:
AssertFailedReturn(VERR_IPE_NOT_REACHED_DEFAULT_CASE);
}
/* Calculate the offset addendum for other VCPUs to use. */
pVM->tm.s.offTSCPause = pVCpu->tm.s.offTSCRawSrc - offTSCRawSrcOld;
}
else
{
/* All other VCPUs (if any). */
pVCpu->tm.s.offTSCRawSrc += pVM->tm.s.offTSCPause;
}
}
return VINF_SUCCESS;
}
/**
* Resumes the CPU timestamp counter ticking.
*
* @returns VBox status code.
* @param pVM The cross context VM structure.
* @param pVCpu The cross context virtual CPU structure.
* @internal
*/
int tmCpuTickResume(PVM pVM, PVMCPU pVCpu)
{
if (!pVCpu->tm.s.fTSCTicking)
{
pVCpu->tm.s.fTSCTicking = true;
/** @todo Test that pausing and resuming doesn't cause lag! (I.e. that we're
* unpaused before the virtual time and stopped after it. */
if (pVM->tm.s.enmTSCMode == TMTSCMODE_REAL_TSC_OFFSET)
pVCpu->tm.s.offTSCRawSrc = SUPReadTsc() - pVCpu->tm.s.u64TSC;
else
pVCpu->tm.s.offTSCRawSrc = tmCpuTickGetRawVirtual(pVM, false /* don't check for pending timers */)
- pVCpu->tm.s.u64TSC;
return VINF_SUCCESS;
}
AssertFailed();
return VERR_TM_TSC_ALREADY_TICKING;
}
