diff options
Diffstat (limited to 'src/VBox/Runtime/common/time/timesupref.h')
| -rw-r--r-- | src/VBox/Runtime/common/time/timesupref.h | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/time/timesupref.h b/src/VBox/Runtime/common/time/timesupref.h new file mode 100644 index 00000000..84322972 --- /dev/null +++ b/src/VBox/Runtime/common/time/timesupref.h @@ -0,0 +1,394 @@ +/* $Id: timesupref.h $ */ +/** @file + * IPRT - Time using SUPLib, the C Code Template. + */ + +/* + * Copyright (C) 2006-2020 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. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL) only, as it comes in the "COPYING.CDDL" file of the + * VirtualBox OSE distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + */ + + +/** + * The C reference implementation of the assembly routines. + * + * Calculate NanoTS using the information in the global information page (GIP) + * which the support library (SUPLib) exports. + * + * This function guarantees that the returned timestamp is later (in time) than + * any previous calls in the same thread. + * + * @remark The way the ever increasing time guarantee is currently implemented means + * that if you call this function at a frequency higher than 1GHz you're in for + * trouble. We currently assume that no idiot will do that for real life purposes. + * + * @returns Nanosecond timestamp. + * @param pData Pointer to the data structure. + */ +RTDECL(uint64_t) rtTimeNanoTSInternalRef(PRTTIMENANOTSDATA pData) +{ +#if TMPL_MODE == TMPL_MODE_SYNC_INVAR_WITH_DELTA && defined(IN_RING3) + PSUPGIPCPU pGipCpuAttemptedTscRecalibration = NULL; +#endif + AssertCompile(RT_IS_POWER_OF_TWO(RTCPUSET_MAX_CPUS)); + + for (;;) + { +#ifndef IN_RING3 /* This simplifies and improves everything. */ + RTCCUINTREG const uFlags = ASMIntDisableFlags(); +#endif + + /* + * Check that the GIP is sane and that the premises for this worker function + * hasn't changed (CPU onlined with bad delta or missing features). + */ + PSUPGLOBALINFOPAGE pGip = g_pSUPGlobalInfoPage; + if ( RT_LIKELY(pGip) + && RT_LIKELY(pGip->u32Magic == SUPGLOBALINFOPAGE_MAGIC) +#if TMPL_MODE == TMPL_MODE_SYNC_INVAR_WITH_DELTA + && RT_LIKELY(pGip->enmUseTscDelta >= SUPGIPUSETSCDELTA_PRACTICALLY_ZERO) +#else + && RT_LIKELY(pGip->enmUseTscDelta <= SUPGIPUSETSCDELTA_ROUGHLY_ZERO) +#endif +#if defined(IN_RING3) && TMPL_GET_CPU_METHOD != 0 + && RT_LIKELY(pGip->fGetGipCpu & TMPL_GET_CPU_METHOD) +#endif + ) + { + /* + * Resolve pGipCpu if needed. If the instruction is serializing, we + * read the transaction id first if possible. + */ +#if TMPL_MODE == TMPL_MODE_ASYNC || TMPL_MODE == TMPL_MODE_SYNC_INVAR_WITH_DELTA +# if defined(IN_RING0) + uint32_t const iCpuSet = RTMpCurSetIndex(); + uint16_t const iGipCpu = iCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx) + ? pGip->aiCpuFromCpuSetIdx[iCpuSet] : UINT16_MAX; +# elif defined(IN_RC) + uint32_t const iCpuSet = VMMGetCpu(&g_VM)->iHostCpuSet; + uint16_t const iGipCpu = iCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx) + ? pGip->aiCpuFromCpuSetIdx[iCpuSet] : UINT16_MAX; +# elif TMPL_GET_CPU_METHOD == SUPGIPGETCPU_APIC_ID +# if TMPL_MODE != TMPL_MODE_ASYNC + uint32_t const u32TransactionId = pGip->aCPUs[0].u32TransactionId; +# endif + uint8_t const idApic = ASMGetApicId(); + uint16_t const iGipCpu = pGip->aiCpuFromApicId[idApic]; +# elif TMPL_GET_CPU_METHOD == SUPGIPGETCPU_APIC_ID_EXT_0B +# if TMPL_MODE != TMPL_MODE_ASYNC + uint32_t const u32TransactionId = pGip->aCPUs[0].u32TransactionId; +# endif + uint32_t const idApic = ASMGetApicIdExt0B(); + uint16_t const iGipCpu = pGip->aiCpuFromApicId[idApic]; +# elif TMPL_GET_CPU_METHOD == SUPGIPGETCPU_APIC_ID_EXT_8000001E +# if TMPL_MODE != TMPL_MODE_ASYNC + uint32_t const u32TransactionId = pGip->aCPUs[0].u32TransactionId; +# endif + uint32_t const idApic = ASMGetApicIdExt8000001E(); + uint16_t const iGipCpu = pGip->aiCpuFromApicId[idApic]; +# elif TMPL_GET_CPU_METHOD == SUPGIPGETCPU_RDTSCP_MASK_MAX_SET_CPUS \ + || TMPL_GET_CPU_METHOD == SUPGIPGETCPU_RDTSCP_GROUP_IN_CH_NUMBER_IN_CL +# if TMPL_MODE != TMPL_MODE_ASYNC + uint32_t const u32TransactionId = pGip->aCPUs[0].u32TransactionId; +# endif + uint32_t uAux; + ASMReadTscWithAux(&uAux); +# if TMPL_GET_CPU_METHOD == SUPGIPGETCPU_RDTSCP_MASK_MAX_SET_CPUS + uint16_t const iCpuSet = uAux & (RTCPUSET_MAX_CPUS - 1); +# else + uint16_t iCpuSet = 0; + uint16_t offGipCpuGroup = pGip->aoffCpuGroup[(uAux >> 8) & UINT8_MAX]; + if (offGipCpuGroup < pGip->cPages * PAGE_SIZE) + { + PSUPGIPCPUGROUP pGipCpuGroup = (PSUPGIPCPUGROUP)((uintptr_t)pGip + offGipCpuGroup); + if ( (uAux & UINT8_MAX) < pGipCpuGroup->cMaxMembers + && pGipCpuGroup->aiCpuSetIdxs[uAux & UINT8_MAX] != -1) + iCpuSet = pGipCpuGroup->aiCpuSetIdxs[uAux & UINT8_MAX]; + } +# endif + uint16_t const iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet]; +# elif TMPL_GET_CPU_METHOD == SUPGIPGETCPU_IDTR_LIMIT_MASK_MAX_SET_CPUS + uint16_t const cbLim = ASMGetIdtrLimit(); + uint16_t const iCpuSet = (cbLim - 256 * (ARCH_BITS == 64 ? 16 : 8)) & (RTCPUSET_MAX_CPUS - 1); + uint16_t const iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet]; +# else +# error "What?" +# endif + if (RT_LIKELY(iGipCpu < pGip->cCpus)) + { + PSUPGIPCPU pGipCpu = &pGip->aCPUs[iGipCpu]; +#else + { +#endif + /* + * Get the transaction ID if necessary and we haven't already + * read it before a serializing instruction above. We can skip + * this for ASYNC_TSC mode in ring-0 and raw-mode context since + * we disable interrupts. + */ +#if TMPL_MODE == TMPL_MODE_ASYNC && defined(IN_RING3) + uint32_t const u32TransactionId = pGipCpu->u32TransactionId; + ASMCompilerBarrier(); + TMPL_READ_FENCE(); +#elif TMPL_MODE != TMPL_MODE_ASYNC \ + && TMPL_GET_CPU_METHOD != SUPGIPGETCPU_APIC_ID \ + && TMPL_GET_CPU_METHOD != SUPGIPGETCPU_APIC_ID_EXT_0B \ + && TMPL_GET_CPU_METHOD != SUPGIPGETCPU_APIC_ID_EXT_8000001E \ + && TMPL_GET_CPU_METHOD != SUPGIPGETCPU_RDTSCP_MASK_MAX_SET_CPUS \ + && TMPL_GET_CPU_METHOD != SUPGIPGETCPU_RDTSCP_GROUP_IN_CH_NUMBER_IN_CL + uint32_t const u32TransactionId = pGip->aCPUs[0].u32TransactionId; + ASMCompilerBarrier(); + TMPL_READ_FENCE(); +#endif + + /* + * Gather all the data we need. The mess at the end is to make + * sure all loads are done before we recheck the transaction ID + * without triggering serializing twice. + */ + uint32_t u32NanoTSFactor0 = pGip->u32UpdateIntervalNS; +#if TMPL_MODE == TMPL_MODE_ASYNC + uint32_t u32UpdateIntervalTSC = pGipCpu->u32UpdateIntervalTSC; + uint64_t u64NanoTS = pGipCpu->u64NanoTS; + uint64_t u64TSC = pGipCpu->u64TSC; +#else + uint32_t u32UpdateIntervalTSC = pGip->aCPUs[0].u32UpdateIntervalTSC; + uint64_t u64NanoTS = pGip->aCPUs[0].u64NanoTS; + uint64_t u64TSC = pGip->aCPUs[0].u64TSC; +# if TMPL_MODE == TMPL_MODE_SYNC_INVAR_WITH_DELTA + int64_t i64TscDelta = pGipCpu->i64TSCDelta; +# endif +#endif + uint64_t u64PrevNanoTS = ASMAtomicUoReadU64(pData->pu64Prev); +#if TMPL_GET_CPU_METHOD == SUPGIPGETCPU_RDTSCP_MASK_MAX_SET_CPUS \ + || TMPL_GET_CPU_METHOD == SUPGIPGETCPU_RDTSCP_GROUP_IN_CH_NUMBER_IN_CL + ASMCompilerBarrier(); + uint32_t uAux2; + uint64_t u64Delta = ASMReadTscWithAux(&uAux2); /* serializing */ +#else + uint64_t u64Delta = ASMReadTSC(); + ASMCompilerBarrier(); +# if TMPL_GET_CPU_METHOD != SUPGIPGETCPU_APIC_ID /* getting APIC will serialize */ \ + && TMPL_GET_CPU_METHOD != SUPGIPGETCPU_APIC_ID_EXT_0B \ + && TMPL_GET_CPU_METHOD != SUPGIPGETCPU_APIC_ID_EXT_8000001E \ + && (defined(IN_RING3) || TMPL_MODE != TMPL_MODE_ASYNC) + TMPL_READ_FENCE(); /* Expensive (~30 ticks). Would like convincing argumentation that let us remove it. */ +# endif +#endif + + /* + * Check that we didn't change CPU. + */ +#if defined(IN_RING3) && ( TMPL_MODE == TMPL_MODE_ASYNC || TMPL_MODE == TMPL_MODE_SYNC_INVAR_WITH_DELTA ) +# if TMPL_GET_CPU_METHOD == SUPGIPGETCPU_APIC_ID + if (RT_LIKELY(ASMGetApicId() == idApic)) +# elif TMPL_GET_CPU_METHOD == SUPGIPGETCPU_APIC_ID_EXT_0B + if (RT_LIKELY(ASMGetApicIdExt0B() == idApic)) +# elif TMPL_GET_CPU_METHOD == SUPGIPGETCPU_APIC_ID_EXT_8000001E + if (RT_LIKELY(ASMGetApicIdExt8000001E() == idApic)) +# elif TMPL_GET_CPU_METHOD == SUPGIPGETCPU_RDTSCP_MASK_MAX_SET_CPUS \ + || TMPL_GET_CPU_METHOD == SUPGIPGETCPU_RDTSCP_GROUP_IN_CH_NUMBER_IN_CL + if (RT_LIKELY(uAux2 == uAux)) +# elif TMPL_GET_CPU_METHOD == SUPGIPGETCPU_IDTR_LIMIT_MASK_MAX_SET_CPUS + if (RT_LIKELY(ASMGetIdtrLimit() == cbLim)) +# endif +#endif + { + /* + * Check the transaction ID (see above for R0/RC + ASYNC). + */ +#if defined(IN_RING3) || TMPL_MODE != TMPL_MODE_ASYNC +# if TMPL_MODE == TMPL_MODE_ASYNC + if (RT_LIKELY(pGipCpu->u32TransactionId == u32TransactionId && !(u32TransactionId & 1) )) +# else + if (RT_LIKELY(pGip->aCPUs[0].u32TransactionId == u32TransactionId && !(u32TransactionId & 1) )) +# endif +#endif + { + + /* + * Apply the TSC delta. If the delta is invalid and the + * execution allows it, try trigger delta recalibration. + */ +#if TMPL_MODE == TMPL_MODE_SYNC_INVAR_WITH_DELTA && defined(IN_RING3) + if (RT_LIKELY( i64TscDelta != INT64_MAX + || pGipCpu == pGipCpuAttemptedTscRecalibration)) +#endif + { +#if TMPL_MODE == TMPL_MODE_SYNC_INVAR_WITH_DELTA +# ifndef IN_RING3 + if (RT_LIKELY(i64TscDelta != INT64_MAX)) +# endif + u64Delta -= i64TscDelta; +#endif + + /* + * Bingo! We've got a consistent set of data. + */ +#ifndef IN_RING3 + ASMSetFlags(uFlags); +#endif + + /* + * Calc NanoTS delta. + */ + u64Delta -= u64TSC; + if (RT_LIKELY(u64Delta <= u32UpdateIntervalTSC)) + { /* MSVC branch hint, probably pointless. */ } + else + { + /* + * We've expired the interval, cap it. If we're here for the 2nd + * time without any GIP update in-between, the checks against + * *pu64Prev below will force 1ns stepping. + */ + ASMAtomicIncU32(&pData->cExpired); + u64Delta = u32UpdateIntervalTSC; + } +#if !defined(_MSC_VER) || !defined(RT_ARCH_X86) /* GCC makes very pretty code from these two inline calls, while MSC cannot. */ + u64Delta = ASMMult2xU32RetU64((uint32_t)u64Delta, u32NanoTSFactor0); + u64Delta = ASMDivU64ByU32RetU32(u64Delta, u32UpdateIntervalTSC); +#else + __asm + { + mov eax, dword ptr [u64Delta] + mul dword ptr [u32NanoTSFactor0] + div dword ptr [u32UpdateIntervalTSC] + mov dword ptr [u64Delta], eax + xor edx, edx + mov dword ptr [u64Delta + 4], edx + } +#endif + + /* + * Calculate the time and compare it with the previously returned value. + */ + u64NanoTS += u64Delta; + uint64_t u64DeltaPrev = u64NanoTS - u64PrevNanoTS; + if (RT_LIKELY( u64DeltaPrev > 0 + && u64DeltaPrev < UINT64_C(86000000000000) /* 24h */)) + { /* Frequent - less than 24h since last call. */ } + else if (RT_LIKELY( (int64_t)u64DeltaPrev <= 0 + && (int64_t)u64DeltaPrev + u32NanoTSFactor0 * 2 >= 0)) + { + /* Occasional - u64NanoTS is in the recent 'past' relative the previous call. */ + ASMAtomicIncU32(&pData->c1nsSteps); + u64NanoTS = u64PrevNanoTS + 1; + } + else if (!u64PrevNanoTS) + /* We're resuming (see TMVirtualResume). */; + else + { + /* Something has gone bust, if negative offset it's real bad. */ + ASMAtomicIncU32(&pData->cBadPrev); + pData->pfnBad(pData, u64NanoTS, u64DeltaPrev, u64PrevNanoTS); + } + + /* + * Attempt updating the previous value, provided we're still ahead of it. + * + * There is no point in recalculating u64NanoTS because we got preempted or if + * we raced somebody while the GIP was updated, since these are events + * that might occur at any point in the return path as well. + */ + if (RT_LIKELY(ASMAtomicCmpXchgU64(pData->pu64Prev, u64NanoTS, u64PrevNanoTS))) + return u64NanoTS; + + ASMAtomicIncU32(&pData->cUpdateRaces); + for (int cTries = 25; cTries > 0; cTries--) + { + u64PrevNanoTS = ASMAtomicReadU64(pData->pu64Prev); + if (u64PrevNanoTS >= u64NanoTS) + break; + if (ASMAtomicCmpXchgU64(pData->pu64Prev, u64NanoTS, u64PrevNanoTS)) + break; + ASMNopPause(); + } + return u64NanoTS; + } + +#if TMPL_MODE == TMPL_MODE_SYNC_INVAR_WITH_DELTA && defined(IN_RING3) + /* + * Call into the support driver to try make it recalculate the delta. We + * remember which GIP CPU structure we're probably working on so we won't + * end up in a loop if the driver for some reason cannot get the job done. + */ + else /* else is unecessary, but helps checking the preprocessor spaghetti. */ + { + pGipCpuAttemptedTscRecalibration = pGipCpu; + uint64_t u64TscTmp; + uint16_t idApicUpdate; + int rc = SUPR3ReadTsc(&u64TscTmp, &idApicUpdate); + if (RT_SUCCESS(rc) && idApicUpdate < RT_ELEMENTS(pGip->aiCpuFromApicId)) + { + uint32_t iUpdateGipCpu = pGip->aiCpuFromApicId[idApicUpdate]; + if (iUpdateGipCpu < pGip->cCpus) + pGipCpuAttemptedTscRecalibration = &pGip->aCPUs[iUpdateGipCpu]; + } + } +#endif + } + } + + /* + * No joy must try again. + */ +#ifdef _MSC_VER +# pragma warning(disable: 4702) +#endif +#ifndef IN_RING3 + ASMSetFlags(uFlags); +#endif + ASMNopPause(); + continue; + } + +#if TMPL_MODE == TMPL_MODE_ASYNC || TMPL_MODE == TMPL_MODE_SYNC_INVAR_WITH_DELTA + /* + * We've got a bad CPU or APIC index of some kind. + */ + else /* else is unecessary, but helps checking the preprocessor spaghetti. */ + { +# ifndef IN_RING3 + ASMSetFlags(uFlags); +# endif +# if defined(IN_RING0) \ + || defined(IN_RC) \ + || ( TMPL_GET_CPU_METHOD != SUPGIPGETCPU_APIC_ID \ + && TMPL_GET_CPU_METHOD != SUPGIPGETCPU_APIC_ID_EXT_0B /*?*/ \ + && TMPL_GET_CPU_METHOD != SUPGIPGETCPU_APIC_ID_EXT_8000001E /*?*/) + return pData->pfnBadCpuIndex(pData, UINT16_MAX-1, iCpuSet, iGipCpu); +# else + return pData->pfnBadCpuIndex(pData, idApic, UINT16_MAX-1, iGipCpu); +# endif + } +#endif + } + + /* + * Something changed in the GIP config or it was unmapped, figure out + * the right worker function to use now. + */ +#ifndef IN_RING3 + ASMSetFlags(uFlags); +#endif + return pData->pfnRediscover(pData); + } +} + |