/**
* Enables the Hyper-V TSC page.
*
* @returns VBox status code.
* @param pVM Pointer to the VM.
* @param GCPhysTscPage Where to map the TSC page.
* @param fUseThisTscSeq Whether to set the TSC sequence number to the one
* specified in @a uTscSeq.
* @param uTscSeq The TSC sequence value to use. Ignored if
* @a fUseThisTscSeq is false.
*/
VMMR3_INT_DECL(int) gimR3HvEnableTscPage(PVM pVM, RTGCPHYS GCPhysTscPage, bool fUseThisTscSeq, uint32_t uTscSeq)
{
PPDMDEVINSR3 pDevIns = pVM->gim.s.pDevInsR3;
PGIMMMIO2REGION pRegion = &pVM->gim.s.u.Hv.aMmio2Regions[GIM_HV_REF_TSC_PAGE_REGION_IDX];
AssertPtrReturn(pDevIns, VERR_GIM_DEVICE_NOT_REGISTERED);
int rc;
if (pRegion->fMapped)
{
/*
* Is it already enabled at the given guest-address?
*/
if (pRegion->GCPhysPage == GCPhysTscPage)
return VINF_SUCCESS;
/*
* If it's mapped at a different address, unmap the previous address.
*/
rc = gimR3HvDisableTscPage(pVM);
AssertRC(rc);
}
/*
* Map the TSC-page at the specified address.
*/
Assert(!pRegion->fMapped);
rc = GIMR3Mmio2Map(pVM, pRegion, GCPhysTscPage);
if (RT_SUCCESS(rc))
{
Assert(pRegion->GCPhysPage == GCPhysTscPage);
/*
* Update the TSC scale. Windows guests expect a non-zero TSC sequence, otherwise
* they fallback to using the reference count MSR which is not ideal in terms of VM-exits.
*
* Also, Hyper-V normalizes the time in 10 MHz, see:
* http://technet.microsoft.com/it-it/sysinternals/dn553408%28v=vs.110%29
*/
PGIMHVREFTSC pRefTsc = (PGIMHVREFTSC)pRegion->pvPageR3;
Assert(pRefTsc);
uint64_t const u64TscKHz = TMCpuTicksPerSecond(pVM) / UINT64_C(1000);
uint32_t u32TscSeq = 1;
if ( fUseThisTscSeq
&& uTscSeq < UINT32_C(0xfffffffe))
u32TscSeq = uTscSeq + 1;
pRefTsc->u32TscSequence = u32TscSeq;
pRefTsc->u64TscScale = ((INT64_C(10000) << 32) / u64TscKHz) << 32;
pRefTsc->i64TscOffset = 0;
LogRel(("GIM: HyperV: Enabled TSC page at %#RGp - u64TscScale=%#RX64 u64TscKHz=%#RX64 (%'RU64) Seq=%#RU32\n",
GCPhysTscPage, pRefTsc->u64TscScale, u64TscKHz, u64TscKHz, pRefTsc->u32TscSequence));
TMR3CpuTickParavirtEnable(pVM);
return VINF_SUCCESS;
}
else
LogRelFunc(("GIMR3Mmio2Map failed. rc=%Rrc\n", rc));
return VERR_GIM_OPERATION_FAILED;
}
/**
* Enables the KVM VCPU system-time structure.
*
* @returns VBox status code.
* @param pVM Pointer to the VM.
* @param pVCpu Pointer to the VMCPU.
*
* @remarks Don't do any release assertions here, these can be triggered by
* guest R0 code.
*/
VMMR3_INT_DECL(int) gimR3KvmEnableSystemTime(PVM pVM, PVMCPU pVCpu)
{
PGIMKVM pKvm = &pVM->gim.s.u.Kvm;
PGIMKVMCPU pKvmCpu = &pVCpu->gim.s.u.KvmCpu;
/*
* Validate the mapping address first.
*/
if (!PGMPhysIsGCPhysNormal(pVM, pKvmCpu->GCPhysSystemTime))
{
LogRel(("GIM: KVM: VCPU%3d: Invalid physical addr requested for mapping system-time struct. GCPhysSystemTime=%#RGp\n",
pVCpu->idCpu, pKvmCpu->GCPhysSystemTime));
return VERR_GIM_OPERATION_FAILED;
}
/*
* Construct the system-time struct.
*/
GIMKVMSYSTEMTIME SystemTime;
RT_ZERO(SystemTime);
SystemTime.u32Version = pKvmCpu->u32SystemTimeVersion;
SystemTime.u64NanoTS = pKvmCpu->uVirtNanoTS;
SystemTime.u64Tsc = pKvmCpu->uTsc;
SystemTime.fFlags = pKvmCpu->fSystemTimeFlags | GIM_KVM_SYSTEM_TIME_FLAGS_TSC_STABLE;
/*
* How the guest calculates the system time (nanoseconds):
*
* tsc = rdtsc - SysTime.u64Tsc
* if (SysTime.i8TscShift >= 0)
* tsc <<= i8TscShift;
* else
* tsc >>= -i8TscShift;
* time = ((tsc * SysTime.u32TscScale) >> 32) + SysTime.u64NanoTS
*/
uint64_t u64TscFreq = pKvm->cTscTicksPerSecond;
SystemTime.i8TscShift = 0;
while (u64TscFreq > 2 * RT_NS_1SEC_64)
{
u64TscFreq >>= 1;
SystemTime.i8TscShift--;
}
uint32_t uTscFreqLo = (uint32_t)u64TscFreq;
while (uTscFreqLo <= RT_NS_1SEC)
{
uTscFreqLo <<= 1;
SystemTime.i8TscShift++;
}
SystemTime.u32TscScale = ASMDivU64ByU32RetU32(RT_NS_1SEC_64 << 32, uTscFreqLo);
/*
* Update guest memory with the system-time struct.
*/
Assert(!(SystemTime.u32Version & UINT32_C(1)));
int rc = PGMPhysSimpleWriteGCPhys(pVM, pKvmCpu->GCPhysSystemTime, &SystemTime, sizeof(GIMKVMSYSTEMTIME));
if (RT_SUCCESS(rc))
{
LogRel(("GIM: KVM: VCPU%3d: Enabled system-time struct. at %#RGp - u32TscScale=%#RX32 i8TscShift=%d uVersion=%#RU32 "
"fFlags=%#x uTsc=%#RX64 uVirtNanoTS=%#RX64\n", pVCpu->idCpu, pKvmCpu->GCPhysSystemTime, SystemTime.u32TscScale,
SystemTime.i8TscShift, SystemTime.u32Version, SystemTime.fFlags, pKvmCpu->uTsc, pKvmCpu->uVirtNanoTS));
TMR3CpuTickParavirtEnable(pVM);
}
else
LogRel(("GIM: KVM: VCPU%3d: Failed to write system-time struct. at %#RGp. rc=%Rrc\n",
pVCpu->idCpu, pKvmCpu->GCPhysSystemTime, rc));
return rc;
}
