SUPDrvGip.cpp revision 5cb0813f7ea960345b7bc247add053f4aa5841aa
eb3a3435bb6f3ad6a38085912929372669c498favboxsync/* $Id$ */
eb3a3435bb6f3ad6a38085912929372669c498favboxsync/** @file
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * VBoxDrv - The VirtualBox Support Driver - Common code for GIP.
eb3a3435bb6f3ad6a38085912929372669c498favboxsync */
eb3a3435bb6f3ad6a38085912929372669c498favboxsync
eb3a3435bb6f3ad6a38085912929372669c498favboxsync/*
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * Copyright (C) 2006-2015 Oracle Corporation
eb3a3435bb6f3ad6a38085912929372669c498favboxsync *
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * This file is part of VirtualBox Open Source Edition (OSE), as
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * available from http://www.virtualbox.org. This file is free software;
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * you can redistribute it and/or modify it under the terms of the GNU
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * General Public License (GPL) as published by the Free Software
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * Foundation, in version 2 as it comes in the "COPYING" file of the
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
eb3a3435bb6f3ad6a38085912929372669c498favboxsync *
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * The contents of this file may alternatively be used under the terms
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * of the Common Development and Distribution License Version 1.0
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * VirtualBox OSE distribution, in which case the provisions of the
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * CDDL are applicable instead of those of the GPL.
eb3a3435bb6f3ad6a38085912929372669c498favboxsync *
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * You may elect to license modified versions of this file under the
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * terms and conditions of either the GPL or the CDDL or both.
eb3a3435bb6f3ad6a38085912929372669c498favboxsync */
eb3a3435bb6f3ad6a38085912929372669c498favboxsync
eb3a3435bb6f3ad6a38085912929372669c498favboxsync/*******************************************************************************
eb3a3435bb6f3ad6a38085912929372669c498favboxsync* Header Files *
eb3a3435bb6f3ad6a38085912929372669c498favboxsync*******************************************************************************/
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#define LOG_GROUP LOG_GROUP_SUP_DRV
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#define SUPDRV_AGNOSTIC
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#include "SUPDrvInternal.h"
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#ifndef PAGE_SHIFT
eb3a3435bb6f3ad6a38085912929372669c498favboxsync# include <iprt/param.h>
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#endif
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#include <iprt/asm.h>
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#include <iprt/asm-amd64-x86.h>
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#include <iprt/asm-math.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#include <iprt/cpuset.h>
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#include <iprt/handletable.h>
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#include <iprt/mem.h>
eb3a3435bb6f3ad6a38085912929372669c498favboxsync#include <iprt/mp.h>
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#include <iprt/power.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#include <iprt/process.h>
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#include <iprt/semaphore.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#include <iprt/spinlock.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#include <iprt/thread.h>
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#include <iprt/uuid.h>
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#include <iprt/net.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#include <iprt/crc.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#include <iprt/string.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#include <iprt/timer.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#if defined(RT_OS_DARWIN) || defined(RT_OS_SOLARIS) || defined(RT_OS_FREEBSD)
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync# include <iprt/rand.h>
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync# include <iprt/path.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#endif
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#include <iprt/uint128.h>
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync#include <iprt/x86.h>
4b783d68e6d569ab798901917ace422a4810edf0vboxsync
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#include <VBox/param.h>
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#include <VBox/log.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#include <VBox/err.h>
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#if defined(RT_OS_SOLARIS) || defined(RT_OS_DARWIN)
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync# include "dtrace/SUPDrv.h"
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#else
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync/* ... */
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#endif
4b783d68e6d569ab798901917ace422a4810edf0vboxsync
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync/*******************************************************************************
4b783d68e6d569ab798901917ace422a4810edf0vboxsync* Defined Constants And Macros *
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync*******************************************************************************/
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync/** The frequency by which we recalculate the u32UpdateHz and
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync * u32UpdateIntervalNS GIP members. The value must be a power of 2.
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync *
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync * Warning: Bumping this too high might overflow u32UpdateIntervalNS.
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync */
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#define GIP_UPDATEHZ_RECALC_FREQ 0x800
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync/** A reserved TSC value used for synchronization as well as measurement of
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync * TSC deltas. */
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#define GIP_TSC_DELTA_RSVD UINT64_MAX
4b783d68e6d569ab798901917ace422a4810edf0vboxsync/** The number of TSC delta measurement loops in total (includes primer and
4b783d68e6d569ab798901917ace422a4810edf0vboxsync * read-time loops). */
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#define GIP_TSC_DELTA_LOOPS 96
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync/** The number of cache primer loops. */
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#define GIP_TSC_DELTA_PRIMER_LOOPS 4
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync/** The number of loops until we keep computing the minumum read time. */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#define GIP_TSC_DELTA_READ_TIME_LOOPS 24
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync/** @name Master / worker synchronization values.
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync * @{ */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** Stop measurement of TSC delta. */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#define GIP_TSC_DELTA_SYNC_STOP UINT32_C(0)
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** Start measurement of TSC delta. */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#define GIP_TSC_DELTA_SYNC_START UINT32_C(1)
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** Worker thread is ready for reading the TSC. */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#define GIP_TSC_DELTA_SYNC_WORKER_READY UINT32_C(2)
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** Worker thread is done updating TSC delta info. */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#define GIP_TSC_DELTA_SYNC_WORKER_DONE UINT32_C(3)
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** When IPRT is isn't concurrent safe: Master is ready and will wait for worker
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync * with a timeout. */
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync#define GIP_TSC_DELTA_SYNC_PRESTART_MASTER UINT32_C(4)
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** @} */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync/** When IPRT is isn't concurrent safe: Worker is ready after waiting for
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync * master with a timeout. */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#define GIP_TSC_DELTA_SYNC_PRESTART_WORKER 5
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** The TSC-refinement interval in seconds. */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#define GIP_TSC_REFINE_PERIOD_IN_SECS 5
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** The TSC-delta threshold for the SUPGIPUSETSCDELTA_PRACTICALLY_ZERO rating */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#define GIP_TSC_DELTA_THRESHOLD_PRACTICALLY_ZERO 32
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** The TSC-delta threshold for the SUPGIPUSETSCDELTA_ROUGHLY_ZERO rating */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#define GIP_TSC_DELTA_THRESHOLD_ROUGHLY_ZERO 448
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** The TSC delta value for the initial GIP master - 0 in regular builds.
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync * To test the delta code this can be set to a non-zero value. */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#if 0
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync# define GIP_TSC_DELTA_INITIAL_MASTER_VALUE INT64_C(170139095182512) /* 0x00009abd9854acb0 */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#else
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync# define GIP_TSC_DELTA_INITIAL_MASTER_VALUE INT64_C(0)
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#endif
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsyncAssertCompile(GIP_TSC_DELTA_PRIMER_LOOPS < GIP_TSC_DELTA_READ_TIME_LOOPS);
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsyncAssertCompile(GIP_TSC_DELTA_PRIMER_LOOPS + GIP_TSC_DELTA_READ_TIME_LOOPS < GIP_TSC_DELTA_LOOPS);
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/** @def VBOX_SVN_REV
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync * The makefile should define this if it can. */
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync#ifndef VBOX_SVN_REV
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync# define VBOX_SVN_REV 0
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#endif
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#if 0 /* Don't start the GIP timers. Useful when debugging the IPRT timer code. */
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync# define DO_NOT_START_GIP
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#endif
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync
4b783d68e6d569ab798901917ace422a4810edf0vboxsync
4b783d68e6d569ab798901917ace422a4810edf0vboxsync/*******************************************************************************
eb3a3435bb6f3ad6a38085912929372669c498favboxsync* Internal Functions *
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync*******************************************************************************/
eb3a3435bb6f3ad6a38085912929372669c498favboxsyncstatic DECLCALLBACK(void) supdrvGipSyncAndInvariantTimer(PRTTIMER pTimer, void *pvUser, uint64_t iTick);
4b783d68e6d569ab798901917ace422a4810edf0vboxsyncstatic DECLCALLBACK(void) supdrvGipAsyncTimer(PRTTIMER pTimer, void *pvUser, uint64_t iTick);
4b783d68e6d569ab798901917ace422a4810edf0vboxsyncstatic void supdrvGipInitCpu(PSUPGLOBALINFOPAGE pGip, PSUPGIPCPU pCpu, uint64_t u64NanoTS, uint64_t uCpuHz);
4b783d68e6d569ab798901917ace422a4810edf0vboxsync#ifdef SUPDRV_USE_TSC_DELTA_THREAD
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsyncstatic int supdrvTscDeltaThreadInit(PSUPDRVDEVEXT pDevExt);
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsyncstatic void supdrvTscDeltaTerm(PSUPDRVDEVEXT pDevExt);
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsyncstatic void supdrvTscDeltaThreadStartMeasurement(PSUPDRVDEVEXT pDevExt);
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#else
eb3a3435bb6f3ad6a38085912929372669c498favboxsyncstatic int supdrvMeasureInitialTscDeltas(PSUPDRVDEVEXT pDevExt);
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsyncstatic int supdrvMeasureTscDeltaOne(PSUPDRVDEVEXT pDevExt, uint32_t idxWorker);
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync#endif
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync/*******************************************************************************
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync* Global Variables *
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync*******************************************************************************/
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsyncDECLEXPORT(PSUPGLOBALINFOPAGE) g_pSUPGlobalInfoPage = NULL;
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync
eb3a3435bb6f3ad6a38085912929372669c498favboxsync/*
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync *
c72f00ff9f31a65845a8722126d37708b61bb6aevboxsync * Misc Common GIP Code
eb3a3435bb6f3ad6a38085912929372669c498favboxsync * Misc Common GIP Code
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync * Misc Common GIP Code
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync *
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync *
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync */
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync
eb3a3435bb6f3ad6a38085912929372669c498favboxsync
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync/**
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync * Finds the GIP CPU index corresponding to @a idCpu.
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync *
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync * @returns GIP CPU array index, UINT32_MAX if not found.
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync * @param pGip The GIP.
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync * @param idCpu The CPU ID.
f13fb2df3059d9304d27e4a594a0401ba9de4c91vboxsync */
eb3a3435bb6f3ad6a38085912929372669c498favboxsyncstatic uint32_t supdrvGipFindCpuIndexForCpuId(PSUPGLOBALINFOPAGE pGip, RTCPUID idCpu)
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync{
4b783d68e6d569ab798901917ace422a4810edf0vboxsync uint32_t i;
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync for (i = 0; i < pGip->cCpus; i++)
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync if (pGip->aCPUs[i].idCpu == idCpu)
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync return i;
29e50fce8a16b6c8955f48b7d1e19cb7aa3694ddvboxsync return UINT32_MAX;
467aa5ec73ac24ab34a04b46ea812955566910dcvboxsync}
4b783d68e6d569ab798901917ace422a4810edf0vboxsync
eb3a3435bb6f3ad6a38085912929372669c498favboxsync
467aa5ec73ac24ab34a04b46ea812955566910dcvboxsync
eb3a3435bb6f3ad6a38085912929372669c498favboxsync/*
4b783d68e6d569ab798901917ace422a4810edf0vboxsync *
* GIP Mapping and Unmapping Related Code.
* GIP Mapping and Unmapping Related Code.
* GIP Mapping and Unmapping Related Code.
*
*
*/
/**
* (Re-)initializes the per-cpu structure prior to starting or resuming the GIP
* updating.
*
* @param pGip Pointer to the GIP.
* @param pGipCpu The per CPU structure for this CPU.
* @param u64NanoTS The current time.
*/
static void supdrvGipReInitCpu(PSUPGLOBALINFOPAGE pGip, PSUPGIPCPU pGipCpu, uint64_t u64NanoTS)
{
/*
* Here we don't really care about applying the TSC delta. The re-initialization of this
* value is not relevant especially while (re)starting the GIP as the first few ones will
* be ignored anyway, see supdrvGipDoUpdateCpu().
*/
pGipCpu->u64TSC = ASMReadTSC() - pGipCpu->u32UpdateIntervalTSC;
pGipCpu->u64NanoTS = u64NanoTS;
}
/**
* Set the current TSC and NanoTS value for the CPU.
*
* @param idCpu The CPU ID. Unused - we have to use the APIC ID.
* @param pvUser1 Pointer to the ring-0 GIP mapping.
* @param pvUser2 Pointer to the variable holding the current time.
*/
static DECLCALLBACK(void) supdrvGipReInitCpuCallback(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
PSUPGLOBALINFOPAGE pGip = (PSUPGLOBALINFOPAGE)pvUser1;
unsigned iCpu = pGip->aiCpuFromApicId[ASMGetApicId()];
if (RT_LIKELY(iCpu < pGip->cCpus && pGip->aCPUs[iCpu].idCpu == idCpu))
supdrvGipReInitCpu(pGip, &pGip->aCPUs[iCpu], *(uint64_t *)pvUser2);
NOREF(pvUser2);
NOREF(idCpu);
}
/**
* State structure for supdrvGipDetectGetGipCpuCallback.
*/
typedef struct SUPDRVGIPDETECTGETCPU
{
/** Bitmap of APIC IDs that has been seen (initialized to zero).
* Used to detect duplicate APIC IDs (paranoia). */
uint8_t volatile bmApicId[256 / 8];
/** Mask of supported GIP CPU getter methods (SUPGIPGETCPU_XXX) (all bits set
* initially). The callback clears the methods not detected. */
uint32_t volatile fSupported;
/** The first callback detecting any kind of range issues (initialized to
* NIL_RTCPUID). */
RTCPUID volatile idCpuProblem;
} SUPDRVGIPDETECTGETCPU;
/** Pointer to state structure for supdrvGipDetectGetGipCpuCallback. */
typedef SUPDRVGIPDETECTGETCPU *PSUPDRVGIPDETECTGETCPU;
/**
* Checks for alternative ways of getting the CPU ID.
*
* This also checks the APIC ID, CPU ID and CPU set index values against the
* GIP tables.
*
* @param idCpu The CPU ID. Unused - we have to use the APIC ID.
* @param pvUser1 Pointer to the state structure.
* @param pvUser2 Pointer to the GIP.
*/
static DECLCALLBACK(void) supdrvGipDetectGetGipCpuCallback(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
PSUPDRVGIPDETECTGETCPU pState = (PSUPDRVGIPDETECTGETCPU)pvUser1;
PSUPGLOBALINFOPAGE pGip = (PSUPGLOBALINFOPAGE)pvUser2;
uint32_t fSupported = 0;
uint16_t idApic;
int iCpuSet;
AssertMsg(idCpu == RTMpCpuId(), ("idCpu=%#x RTMpCpuId()=%#x\n", idCpu, RTMpCpuId())); /* paranoia^3 */
/*
* Check that the CPU ID and CPU set index are interchangable.
*/
iCpuSet = RTMpCpuIdToSetIndex(idCpu);
if ((RTCPUID)iCpuSet == idCpu)
{
AssertCompile(RT_IS_POWER_OF_TWO(RTCPUSET_MAX_CPUS));
if ( iCpuSet >= 0
&& iCpuSet < RTCPUSET_MAX_CPUS
&& RT_IS_POWER_OF_TWO(RTCPUSET_MAX_CPUS))
{
/*
* Check whether the IDTR.LIMIT contains a CPU number.
*/
#ifdef RT_ARCH_X86
uint16_t const cbIdt = sizeof(X86DESC64SYSTEM) * 256;
#else
uint16_t const cbIdt = sizeof(X86DESCGATE) * 256;
#endif
RTIDTR Idtr;
ASMGetIDTR(&Idtr);
if (Idtr.cbIdt >= cbIdt)
{
uint32_t uTmp = Idtr.cbIdt - cbIdt;
uTmp &= RTCPUSET_MAX_CPUS - 1;
if (uTmp == idCpu)
{
RTIDTR Idtr2;
ASMGetIDTR(&Idtr2);
if (Idtr2.cbIdt == Idtr.cbIdt)
fSupported |= SUPGIPGETCPU_IDTR_LIMIT_MASK_MAX_SET_CPUS;
}
}
/*
* Check whether RDTSCP is an option.
*/
if (ASMHasCpuId())
{
if ( ASMIsValidExtRange(ASMCpuId_EAX(UINT32_C(0x80000000)))
&& (ASMCpuId_EDX(UINT32_C(0x80000001)) & X86_CPUID_EXT_FEATURE_EDX_RDTSCP) )
{
uint32_t uAux;
ASMReadTscWithAux(&uAux);
if ((uAux & (RTCPUSET_MAX_CPUS - 1)) == idCpu)
{
ASMNopPause();
ASMReadTscWithAux(&uAux);
if ((uAux & (RTCPUSET_MAX_CPUS - 1)) == idCpu)
fSupported |= SUPGIPGETCPU_RDTSCP_MASK_MAX_SET_CPUS;
}
}
}
}
}
/*
* Check that the APIC ID is unique.
*/
idApic = ASMGetApicId();
if (RT_LIKELY( idApic < RT_ELEMENTS(pGip->aiCpuFromApicId)
&& !ASMAtomicBitTestAndSet(pState->bmApicId, idApic)))
fSupported |= SUPGIPGETCPU_APIC_ID;
else
{
AssertCompile(sizeof(pState->bmApicId) * 8 == RT_ELEMENTS(pGip->aiCpuFromApicId));
ASMAtomicCmpXchgU32(&pState->idCpuProblem, idCpu, NIL_RTCPUID);
LogRel(("supdrvGipDetectGetGipCpuCallback: idCpu=%#x iCpuSet=%d idApic=%#x - duplicate APIC ID.\n",
idCpu, iCpuSet, idApic));
}
/*
* Check that the iCpuSet is within the expected range.
*/
if (RT_UNLIKELY( iCpuSet < 0
|| (unsigned)iCpuSet >= RTCPUSET_MAX_CPUS
|| (unsigned)iCpuSet >= RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)))
{
ASMAtomicCmpXchgU32(&pState->idCpuProblem, idCpu, NIL_RTCPUID);
LogRel(("supdrvGipDetectGetGipCpuCallback: idCpu=%#x iCpuSet=%d idApic=%#x - CPU set index is out of range.\n",
idCpu, iCpuSet, idApic));
}
else
{
RTCPUID idCpu2 = RTMpCpuIdFromSetIndex(iCpuSet);
if (RT_UNLIKELY(idCpu2 != idCpu))
{
ASMAtomicCmpXchgU32(&pState->idCpuProblem, idCpu, NIL_RTCPUID);
LogRel(("supdrvGipDetectGetGipCpuCallback: idCpu=%#x iCpuSet=%d idApic=%#x - CPU id/index roundtrip problem: %#x\n",
idCpu, iCpuSet, idApic, idCpu2));
}
}
/*
* Update the supported feature mask before we return.
*/
ASMAtomicAndU32(&pState->fSupported, fSupported);
NOREF(pvUser2);
}
/**
* Increase the timer freqency on hosts where this is possible (NT).
*
* The idea is that more interrupts is better for us... Also, it's better than
* we increase the timer frequence, because we might end up getting inaccurate
* callbacks if someone else does it.
*
* @param pDevExt Sets u32SystemTimerGranularityGrant if increased.
*/
static void supdrvGipRequestHigherTimerFrequencyFromSystem(PSUPDRVDEVEXT pDevExt)
{
if (pDevExt->u32SystemTimerGranularityGrant == 0)
{
uint32_t u32SystemResolution;
if ( RT_SUCCESS_NP(RTTimerRequestSystemGranularity( 976563 /* 1024 HZ */, &u32SystemResolution))
|| RT_SUCCESS_NP(RTTimerRequestSystemGranularity( 1000000 /* 1000 HZ */, &u32SystemResolution))
|| RT_SUCCESS_NP(RTTimerRequestSystemGranularity( 1953125 /* 512 HZ */, &u32SystemResolution))
|| RT_SUCCESS_NP(RTTimerRequestSystemGranularity( 2000000 /* 500 HZ */, &u32SystemResolution))
)
{
Assert(RTTimerGetSystemGranularity() <= u32SystemResolution);
pDevExt->u32SystemTimerGranularityGrant = u32SystemResolution;
}
}
}
/**
* Undoes supdrvGipRequestHigherTimerFrequencyFromSystem.
*
* @param pDevExt Clears u32SystemTimerGranularityGrant.
*/
static void supdrvGipReleaseHigherTimerFrequencyFromSystem(PSUPDRVDEVEXT pDevExt)
{
if (pDevExt->u32SystemTimerGranularityGrant)
{
int rc2 = RTTimerReleaseSystemGranularity(pDevExt->u32SystemTimerGranularityGrant);
AssertRC(rc2);
pDevExt->u32SystemTimerGranularityGrant = 0;
}
}
/**
* Maps the GIP into userspace and/or get the physical address of the GIP.
*
* @returns IPRT status code.
* @param pSession Session to which the GIP mapping should belong.
* @param ppGipR3 Where to store the address of the ring-3 mapping. (optional)
* @param pHCPhysGip Where to store the physical address. (optional)
*
* @remark There is no reference counting on the mapping, so one call to this function
* count globally as one reference. One call to SUPR0GipUnmap() is will unmap GIP
* and remove the session as a GIP user.
*/
SUPR0DECL(int) SUPR0GipMap(PSUPDRVSESSION pSession, PRTR3PTR ppGipR3, PRTHCPHYS pHCPhysGip)
{
int rc;
PSUPDRVDEVEXT pDevExt = pSession->pDevExt;
RTR3PTR pGipR3 = NIL_RTR3PTR;
RTHCPHYS HCPhys = NIL_RTHCPHYS;
LogFlow(("SUPR0GipMap: pSession=%p ppGipR3=%p pHCPhysGip=%p\n", pSession, ppGipR3, pHCPhysGip));
/*
* Validate
*/
AssertReturn(SUP_IS_SESSION_VALID(pSession), VERR_INVALID_PARAMETER);
AssertPtrNullReturn(ppGipR3, VERR_INVALID_POINTER);
AssertPtrNullReturn(pHCPhysGip, VERR_INVALID_POINTER);
#ifdef SUPDRV_USE_MUTEX_FOR_GIP
RTSemMutexRequest(pDevExt->mtxGip, RT_INDEFINITE_WAIT);
#else
RTSemFastMutexRequest(pDevExt->mtxGip);
#endif
if (pDevExt->pGip)
{
/*
* Map it?
*/
rc = VINF_SUCCESS;
if (ppGipR3)
{
if (pSession->GipMapObjR3 == NIL_RTR0MEMOBJ)
rc = RTR0MemObjMapUser(&pSession->GipMapObjR3, pDevExt->GipMemObj, (RTR3PTR)-1, 0,
RTMEM_PROT_READ, RTR0ProcHandleSelf());
if (RT_SUCCESS(rc))
pGipR3 = RTR0MemObjAddressR3(pSession->GipMapObjR3);
}
/*
* Get physical address.
*/
if (pHCPhysGip && RT_SUCCESS(rc))
HCPhys = pDevExt->HCPhysGip;
/*
* Reference globally.
*/
if (!pSession->fGipReferenced && RT_SUCCESS(rc))
{
pSession->fGipReferenced = 1;
pDevExt->cGipUsers++;
if (pDevExt->cGipUsers == 1)
{
PSUPGLOBALINFOPAGE pGipR0 = pDevExt->pGip;
uint64_t u64NanoTS;
/*
* GIP starts/resumes updating again. On windows we bump the
* host timer frequency to make sure we don't get stuck in guest
* mode and to get better timer (and possibly clock) accuracy.
*/
LogFlow(("SUPR0GipMap: Resumes GIP updating\n"));
supdrvGipRequestHigherTimerFrequencyFromSystem(pDevExt);
/*
* document me
*/
if (pGipR0->aCPUs[0].u32TransactionId != 2 /* not the first time */)
{
unsigned i;
for (i = 0; i < pGipR0->cCpus; i++)
ASMAtomicUoWriteU32(&pGipR0->aCPUs[i].u32TransactionId,
(pGipR0->aCPUs[i].u32TransactionId + GIP_UPDATEHZ_RECALC_FREQ * 2)
& ~(GIP_UPDATEHZ_RECALC_FREQ * 2 - 1));
ASMAtomicWriteU64(&pGipR0->u64NanoTSLastUpdateHz, 0);
}
/*
* document me
*/
u64NanoTS = RTTimeSystemNanoTS() - pGipR0->u32UpdateIntervalNS;
if ( pGipR0->u32Mode == SUPGIPMODE_INVARIANT_TSC
|| pGipR0->u32Mode == SUPGIPMODE_SYNC_TSC
|| RTMpGetOnlineCount() == 1)
supdrvGipReInitCpu(pGipR0, &pGipR0->aCPUs[0], u64NanoTS);
else
RTMpOnAll(supdrvGipReInitCpuCallback, pGipR0, &u64NanoTS);
/*
* Detect alternative ways to figure the CPU ID in ring-3 and
* raw-mode context. Check the sanity of the APIC IDs, CPU IDs,
* and CPU set indexes while we're at it.
*/
if (RT_SUCCESS(rc))
{
SUPDRVGIPDETECTGETCPU DetectState;
RT_BZERO((void *)&DetectState.bmApicId, sizeof(DetectState.bmApicId));
DetectState.fSupported = UINT32_MAX;
DetectState.idCpuProblem = NIL_RTCPUID;
rc = RTMpOnAll(supdrvGipDetectGetGipCpuCallback, &DetectState, pGipR0);
if (DetectState.idCpuProblem == NIL_RTCPUID)
{
if ( DetectState.fSupported != UINT32_MAX
&& DetectState.fSupported != 0)
{
if (pGipR0->fGetGipCpu != DetectState.fSupported)
{
pGipR0->fGetGipCpu = DetectState.fSupported;
LogRel(("SUPR0GipMap: fGetGipCpu=%#x\n", DetectState.fSupported));
}
}
else
{
LogRel(("SUPR0GipMap: No supported ways of getting the APIC ID or CPU number in ring-3! (%#x)\n",
DetectState.fSupported));
rc = VERR_UNSUPPORTED_CPU;
}
}
else
{
LogRel(("SUPR0GipMap: APIC ID, CPU ID or CPU set index problem detected on CPU #%u (%#x)!\n",
DetectState.idCpuProblem, DetectState.idCpuProblem));
rc = VERR_INVALID_CPU_ID;
}
}
/*
* Start the GIP timer if all is well..
*/
if (RT_SUCCESS(rc))
{
#ifndef DO_NOT_START_GIP
rc = RTTimerStart(pDevExt->pGipTimer, 0 /* fire ASAP */); AssertRC(rc);
#endif
rc = VINF_SUCCESS;
}
/*
* Bail out on error.
*/
if (RT_FAILURE(rc))
{
LogRel(("SUPR0GipMap: failed rc=%Rrc\n", rc));
pDevExt->cGipUsers = 0;
pSession->fGipReferenced = 0;
if (pSession->GipMapObjR3 != NIL_RTR0MEMOBJ)
{
int rc2 = RTR0MemObjFree(pSession->GipMapObjR3, false); AssertRC(rc2);
if (RT_SUCCESS(rc2))
pSession->GipMapObjR3 = NIL_RTR0MEMOBJ;
}
HCPhys = NIL_RTHCPHYS;
pGipR3 = NIL_RTR3PTR;
}
}
}
}
else
{
rc = VERR_GENERAL_FAILURE;
Log(("SUPR0GipMap: GIP is not available!\n"));
}
#ifdef SUPDRV_USE_MUTEX_FOR_GIP
RTSemMutexRelease(pDevExt->mtxGip);
#else
RTSemFastMutexRelease(pDevExt->mtxGip);
#endif
/*
* Write returns.
*/
if (pHCPhysGip)
*pHCPhysGip = HCPhys;
if (ppGipR3)
*ppGipR3 = pGipR3;
#ifdef DEBUG_DARWIN_GIP
OSDBGPRINT(("SUPR0GipMap: returns %d *pHCPhysGip=%lx pGipR3=%p\n", rc, (unsigned long)HCPhys, (void *)pGipR3));
#else
LogFlow(( "SUPR0GipMap: returns %d *pHCPhysGip=%lx pGipR3=%p\n", rc, (unsigned long)HCPhys, (void *)pGipR3));
#endif
return rc;
}
/**
* Unmaps any user mapping of the GIP and terminates all GIP access
* from this session.
*
* @returns IPRT status code.
* @param pSession Session to which the GIP mapping should belong.
*/
SUPR0DECL(int) SUPR0GipUnmap(PSUPDRVSESSION pSession)
{
int rc = VINF_SUCCESS;
PSUPDRVDEVEXT pDevExt = pSession->pDevExt;
#ifdef DEBUG_DARWIN_GIP
OSDBGPRINT(("SUPR0GipUnmap: pSession=%p pGip=%p GipMapObjR3=%p\n",
pSession,
pSession->GipMapObjR3 != NIL_RTR0MEMOBJ ? RTR0MemObjAddress(pSession->GipMapObjR3) : NULL,
pSession->GipMapObjR3));
#else
LogFlow(("SUPR0GipUnmap: pSession=%p\n", pSession));
#endif
AssertReturn(SUP_IS_SESSION_VALID(pSession), VERR_INVALID_PARAMETER);
#ifdef SUPDRV_USE_MUTEX_FOR_GIP
RTSemMutexRequest(pDevExt->mtxGip, RT_INDEFINITE_WAIT);
#else
RTSemFastMutexRequest(pDevExt->mtxGip);
#endif
/*
* Unmap anything?
*/
if (pSession->GipMapObjR3 != NIL_RTR0MEMOBJ)
{
rc = RTR0MemObjFree(pSession->GipMapObjR3, false);
AssertRC(rc);
if (RT_SUCCESS(rc))
pSession->GipMapObjR3 = NIL_RTR0MEMOBJ;
}
/*
* Dereference global GIP.
*/
if (pSession->fGipReferenced && !rc)
{
pSession->fGipReferenced = 0;
if ( pDevExt->cGipUsers > 0
&& !--pDevExt->cGipUsers)
{
LogFlow(("SUPR0GipUnmap: Suspends GIP updating\n"));
#ifndef DO_NOT_START_GIP
rc = RTTimerStop(pDevExt->pGipTimer); AssertRC(rc); rc = VINF_SUCCESS;
#endif
supdrvGipReleaseHigherTimerFrequencyFromSystem(pDevExt);
}
}
#ifdef SUPDRV_USE_MUTEX_FOR_GIP
RTSemMutexRelease(pDevExt->mtxGip);
#else
RTSemFastMutexRelease(pDevExt->mtxGip);
#endif
return rc;
}
/**
* Gets the GIP pointer.
*
* @returns Pointer to the GIP or NULL.
*/
SUPDECL(PSUPGLOBALINFOPAGE) SUPGetGIP(void)
{
return g_pSUPGlobalInfoPage;
}
/*
*
*
* GIP Initialization, Termination and CPU Offline / Online Related Code.
* GIP Initialization, Termination and CPU Offline / Online Related Code.
* GIP Initialization, Termination and CPU Offline / Online Related Code.
*
*
*/
/**
* Used by supdrvInitRefineInvariantTscFreqTimer and supdrvGipInitMeasureTscFreq
* to update the TSC frequency related GIP variables.
*
* @param pGip The GIP.
* @param nsElapsed The number of nano seconds elapsed.
* @param cElapsedTscTicks The corresponding number of TSC ticks.
* @param iTick The tick number for debugging.
*/
static void supdrvGipInitSetCpuFreq(PSUPGLOBALINFOPAGE pGip, uint64_t nsElapsed, uint64_t cElapsedTscTicks, uint32_t iTick)
{
/*
* Calculate the frequency.
*/
uint64_t uCpuHz;
if ( cElapsedTscTicks < UINT64_MAX / RT_NS_1SEC
&& nsElapsed < UINT32_MAX)
uCpuHz = ASMMultU64ByU32DivByU32(cElapsedTscTicks, RT_NS_1SEC, (uint32_t)nsElapsed);
else
{
RTUINT128U CpuHz, Tmp, Divisor;
CpuHz.s.Lo = CpuHz.s.Hi = 0;
RTUInt128MulU64ByU64(&Tmp, cElapsedTscTicks, RT_NS_1SEC_64);
RTUInt128Div(&CpuHz, &Tmp, RTUInt128AssignU64(&Divisor, nsElapsed));
uCpuHz = CpuHz.s.Lo;
}
/*
* Update the GIP.
*/
ASMAtomicWriteU64(&pGip->u64CpuHz, uCpuHz);
if (pGip->u32Mode != SUPGIPMODE_ASYNC_TSC)
{
ASMAtomicWriteU64(&pGip->aCPUs[0].u64CpuHz, uCpuHz);
/* For inspecting the frequency calcs using tstGIP-2, debugger or similar. */
if (iTick + 1 < pGip->cCpus)
ASMAtomicWriteU64(&pGip->aCPUs[iTick + 1].u64CpuHz, uCpuHz);
}
}
/**
* Timer callback function for TSC frequency refinement in invariant GIP mode.
*
* This is started during driver init and fires once
* GIP_TSC_REFINE_PERIOD_IN_SECS seconds later.
*
* @param pTimer The timer.
* @param pvUser Opaque pointer to the device instance data.
* @param iTick The timer tick.
*/
static DECLCALLBACK(void) supdrvInitRefineInvariantTscFreqTimer(PRTTIMER pTimer, void *pvUser, uint64_t iTick)
{
PSUPDRVDEVEXT pDevExt = (PSUPDRVDEVEXT)pvUser;
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
RTCPUID idCpu;
uint64_t cNsElapsed;
uint64_t cTscTicksElapsed;
uint64_t nsNow;
uint64_t uTsc;
RTCCUINTREG fEFlags;
/* Paranoia. */
AssertReturnVoid(pGip);
AssertReturnVoid(pGip->u32Mode == SUPGIPMODE_INVARIANT_TSC);
/*
* If we got a power event, stop the refinement process.
*/
if (pDevExt->fInvTscRefinePowerEvent)
{
int rc = RTTimerStop(pTimer); AssertRC(rc);
return;
}
/*
* Try get close to the next clock tick as usual.
*
* PORTME: If timers are called from the clock interrupt handler, or
* an interrupt handler with higher priority than the clock
* interrupt, or spinning for ages in timer handlers is frowned
* upon, this loop must be disabled!
*
* Darwin, FreeBSD, Linux, Solaris, Windows 8.1+:
* High RTTimeSystemNanoTS resolution should prevent any noticable
* spinning her.
*
* Windows 8.0 and earlier:
* We're running in a DPC here, so we may trigger the DPC watchdog?
*
* OS/2:
* Timer callbacks are done in the clock interrupt, so skip it.
*/
#if 0 /* Does this trigger the DPC watchdog? */
#if !defined(RT_OS_OS2)
nsNow = RTTimeSystemNanoTS();
while (RTTimeSystemNanoTS() == nsNow)
ASMNopPause();
#endif
#endif
fEFlags = ASMIntDisableFlags();
uTsc = ASMReadTSC();
nsNow = RTTimeSystemNanoTS();
idCpu = RTMpCpuId();
ASMSetFlags(fEFlags);
cNsElapsed = nsNow - pDevExt->nsStartInvarTscRefine;
cTscTicksElapsed = uTsc - pDevExt->uTscStartInvarTscRefine;
/*
* If the above measurement was taken on a different CPU than the one we
* started the process on, cTscTicksElapsed will need to be adjusted with
* the TSC deltas of both the CPUs.
*
* We ASSUME that the delta calculation process takes less time than the
* TSC frequency refinement timer. If it doesn't, we'll complain and
* drop the frequency refinement.
*
* Note! We cannot entirely trust enmUseTscDelta here because it's
* downgraded after each delta calculation.
*/
if ( idCpu != pDevExt->idCpuInvarTscRefine
&& pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED)
{
uint32_t iStartCpuSet = RTMpCpuIdToSetIndex(pDevExt->idCpuInvarTscRefine);
uint32_t iStopCpuSet = RTMpCpuIdToSetIndex(idCpu);
uint16_t iStartGipCpu = iStartCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)
? pGip->aiCpuFromCpuSetIdx[iStartCpuSet] : UINT16_MAX;
uint16_t iStopGipCpu = iStopCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)
? pGip->aiCpuFromCpuSetIdx[iStopCpuSet] : UINT16_MAX;
int64_t iStartTscDelta = iStartGipCpu < pGip->cCpus ? pGip->aCPUs[iStartGipCpu].i64TSCDelta : INT64_MAX;
int64_t iStopTscDelta = iStopGipCpu < pGip->cCpus ? pGip->aCPUs[iStopGipCpu].i64TSCDelta : INT64_MAX;
if (RT_LIKELY(iStartTscDelta != INT64_MAX && iStopTscDelta != INT64_MAX))
{
if (pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_PRACTICALLY_ZERO)
{
/* cTscTicksElapsed = (uTsc - iStopTscDelta) - (pDevExt->uTscStartInvarTscRefine - iStartTscDelta); */
cTscTicksElapsed += iStartTscDelta - iStopTscDelta;
}
}
/*
* Allow 5 times the refinement period to elapse before we give up on the TSC delta
* calculations.
*/
else if (cNsElapsed > GIP_TSC_REFINE_PERIOD_IN_SECS * 5 * RT_NS_1SEC_64)
{
SUPR0Printf("vboxdrv: Failed to refine invariant TSC frequency because deltas are unavailable after %u (%u) seconds\n",
(uint32_t)(cNsElapsed / RT_NS_1SEC), GIP_TSC_REFINE_PERIOD_IN_SECS);
SUPR0Printf("vboxdrv: start: %u, %u, %#llx stop: %u, %u, %#llx\n",
iStartCpuSet, iStartGipCpu, iStartTscDelta, iStopCpuSet, iStopGipCpu, iStopTscDelta);
int rc = RTTimerStop(pTimer); AssertRC(rc);
return;
}
}
/*
* Calculate and update the CPU frequency variables in GIP.
*
* If there is a GIP user already and we've already refined the frequency
* a couple of times, don't update it as we want a stable frequency value
* for all VMs.
*/
if ( pDevExt->cGipUsers == 0
|| cNsElapsed < RT_NS_1SEC * 2)
{
supdrvGipInitSetCpuFreq(pGip, cNsElapsed, cTscTicksElapsed, (uint32_t)iTick);
/*
* Stop the timer once we've reached the defined refinement period.
*/
if (cNsElapsed > GIP_TSC_REFINE_PERIOD_IN_SECS * RT_NS_1SEC_64)
{
int rc = RTTimerStop(pTimer);
AssertRC(rc);
}
}
else
{
int rc = RTTimerStop(pTimer);
AssertRC(rc);
}
}
/**
* @callback_method_impl{FNRTPOWERNOTIFICATION}
*/
static DECLCALLBACK(void) supdrvGipPowerNotificationCallback(RTPOWEREVENT enmEvent, void *pvUser)
{
PSUPDRVDEVEXT pDevExt = (PSUPDRVDEVEXT)pvUser;
/*
* If the TSC frequency refinement timer we need to cancel it so it doesn't screw
* up the frequency after a long suspend.
*/
if ( enmEvent == RTPOWEREVENT_SUSPEND
|| enmEvent == RTPOWEREVENT_RESUME)
ASMAtomicWriteBool(&pDevExt->fInvTscRefinePowerEvent, true);
}
/**
* Start the TSC-frequency refinment timer for the invariant TSC GIP mode.
*
* We cannot use this in the synchronous and asynchronous tsc GIP modes because
* the CPU may change the TSC frequence between now and when the timer fires
* (supdrvInitAsyncRefineTscTimer).
*
* @param pDevExt Pointer to the device instance data.
* @param pGip Pointer to the GIP.
*/
static void supdrvGipInitStartTimerForRefiningInvariantTscFreq(PSUPDRVDEVEXT pDevExt, PSUPGLOBALINFOPAGE pGip)
{
uint64_t u64NanoTS;
RTCCUINTREG fEFlags;
int rc;
/*
* Register a power management callback.
*/
pDevExt->fInvTscRefinePowerEvent = false;
rc = RTPowerNotificationRegister(supdrvGipPowerNotificationCallback, pDevExt);
AssertRC(rc); /* ignore */
/*
* Record the TSC and NanoTS as the starting anchor point for refinement
* of the TSC. We try get as close to a clock tick as possible on systems
* which does not provide high resolution time.
*/
u64NanoTS = RTTimeSystemNanoTS();
while (RTTimeSystemNanoTS() == u64NanoTS)
ASMNopPause();
fEFlags = ASMIntDisableFlags();
pDevExt->uTscStartInvarTscRefine = ASMReadTSC();
pDevExt->nsStartInvarTscRefine = RTTimeSystemNanoTS();
pDevExt->idCpuInvarTscRefine = RTMpCpuId();
ASMSetFlags(fEFlags);
/*
* Create a timer that runs on the same CPU so we won't have a depencency
* on the TSC-delta and can run in parallel to it. On systems that does not
* implement CPU specific timers we'll apply deltas in the timer callback,
* just like we do for CPUs going offline.
*
* The longer the refinement interval the better the accuracy, at least in
* theory. If it's too long though, ring-3 may already be starting its
* first VMs before we're done. On most systems we will be loading the
* support driver during boot and VMs won't be started for a while yet,
* it is really only a problem during development (especially with
* on-demand driver starting on windows).
*
* To avoid wasting time doing a long supdrvGipInitMeasureTscFreq() call
* to calculate the frequency during driver loading, the timer is set
* to fire after 200 ms the first time. It will then reschedule itself
* to fire every second until GIP_TSC_REFINE_PERIOD_IN_SECS has been
* reached or it notices that there is a user land client with GIP
* mapped (we want a stable frequency for all VMs).
*/
rc = RTTimerCreateEx(&pDevExt->pInvarTscRefineTimer, RT_NS_1SEC,
RTTIMER_FLAGS_CPU(RTMpCpuIdToSetIndex(pDevExt->idCpuInvarTscRefine)),
supdrvInitRefineInvariantTscFreqTimer, pDevExt);
if (RT_SUCCESS(rc))
{
rc = RTTimerStart(pDevExt->pInvarTscRefineTimer, 2*RT_NS_100MS);
if (RT_SUCCESS(rc))
return;
RTTimerDestroy(pDevExt->pInvarTscRefineTimer);
}
if (rc == VERR_CPU_OFFLINE || rc == VERR_NOT_SUPPORTED)
{
rc = RTTimerCreateEx(&pDevExt->pInvarTscRefineTimer, RT_NS_1SEC, RTTIMER_FLAGS_CPU_ANY,
supdrvInitRefineInvariantTscFreqTimer, pDevExt);
if (RT_SUCCESS(rc))
{
rc = RTTimerStart(pDevExt->pInvarTscRefineTimer, 2*RT_NS_100MS);
if (RT_SUCCESS(rc))
return;
RTTimerDestroy(pDevExt->pInvarTscRefineTimer);
}
}
pDevExt->pInvarTscRefineTimer = NULL;
OSDBGPRINT(("vboxdrv: Failed to create or start TSC frequency refinement timer: rc=%Rrc\n", rc));
}
/**
* @callback_method_impl{PFNRTMPWORKER,
* RTMpOnSpecific callback for reading TSC and time on the CPU we started
* the measurements on.}
*/
DECLCALLBACK(void) supdrvGipInitReadTscAndNanoTsOnCpu(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
RTCCUINTREG fEFlags = ASMIntDisableFlags();
uint64_t *puTscStop = (uint64_t *)pvUser1;
uint64_t *pnsStop = (uint64_t *)pvUser2;
*puTscStop = ASMReadTSC();
*pnsStop = RTTimeSystemNanoTS();
ASMSetFlags(fEFlags);
}
/**
* Measures the TSC frequency of the system.
*
* The TSC frequency can vary on systems which are not reported as invariant.
* On such systems the object of this function is to find out what the nominal,
* maximum TSC frequency under 'normal' CPU operation.
*
* @returns VBox status code.
* @param pDevExt Pointer to the device instance.
* @param pGip Pointer to the GIP.
* @param fRough Set if we're doing the rough calculation that the
* TSC measuring code needs, where accuracy isn't all
* that important (too high is better than to low).
* When clear we try for best accuracy that we can
* achieve in reasonably short time.
*/
static int supdrvGipInitMeasureTscFreq(PSUPDRVDEVEXT pDevExt, PSUPGLOBALINFOPAGE pGip, bool fRough)
{
uint32_t nsTimerIncr = RTTimerGetSystemGranularity();
int cTriesLeft = fRough ? 4 : 2;
while (cTriesLeft-- > 0)
{
RTCCUINTREG fEFlags;
uint64_t nsStart;
uint64_t nsStop;
uint64_t uTscStart;
uint64_t uTscStop;
RTCPUID idCpuStart;
RTCPUID idCpuStop;
/*
* Synchronize with the host OS clock tick on systems without high
* resolution time API (older Windows version for example).
*/
nsStart = RTTimeSystemNanoTS();
while (RTTimeSystemNanoTS() == nsStart)
ASMNopPause();
/*
* Read the TSC and current time, noting which CPU we're on.
*/
fEFlags = ASMIntDisableFlags();
uTscStart = ASMReadTSC();
nsStart = RTTimeSystemNanoTS();
idCpuStart = RTMpCpuId();
ASMSetFlags(fEFlags);
/*
* Delay for a while.
*/
if (pGip->u32Mode == SUPGIPMODE_INVARIANT_TSC)
{
/*
* Sleep-wait since the TSC frequency is constant, it eases host load.
* Shorter interval produces more variance in the frequency (esp. Windows).
*/
uint64_t msElapsed = 0;
uint64_t msDelay = ( ((fRough ? 16 : 200) * RT_NS_1MS + nsTimerIncr - 1) / nsTimerIncr * nsTimerIncr - RT_NS_100US )
/ RT_NS_1MS;
do
{
RTThreadSleep((RTMSINTERVAL)(msDelay - msElapsed));
nsStop = RTTimeSystemNanoTS();
msElapsed = (nsStop - nsStart) / RT_NS_1MS;
} while (msElapsed < msDelay);
while (RTTimeSystemNanoTS() == nsStop)
ASMNopPause();
}
else
{
/*
* Busy-wait keeping the frequency up.
*/
do
{
ASMNopPause();
nsStop = RTTimeSystemNanoTS();
} while (nsStop - nsStart < RT_NS_100MS);
}
/*
* Read the TSC and time again.
*/
fEFlags = ASMIntDisableFlags();
uTscStop = ASMReadTSC();
nsStop = RTTimeSystemNanoTS();
idCpuStop = RTMpCpuId();
ASMSetFlags(fEFlags);
/*
* If the CPU changes things get a bit complicated and what we
* can get away with depends on the GIP mode / TSC reliablity.
*/
if (idCpuStop != idCpuStart)
{
bool fDoXCall = false;
/*
* Synchronous TSC mode: we're probably fine as it's unlikely
* that we were rescheduled because of TSC throttling or power
* management reasons, so just go ahead.
*/
if (pGip->u32Mode == SUPGIPMODE_SYNC_TSC)
{
/* Probably ok, maybe we should retry once?. */
Assert(pGip->enmUseTscDelta == SUPGIPUSETSCDELTA_NOT_APPLICABLE);
}
/*
* If we're just doing the rough measurement, do the cross call and
* get on with things (we don't have deltas!).
*/
else if (fRough)
fDoXCall = true;
/*
* Invariant TSC mode: It doesn't matter if we have delta available
* for both CPUs. That is not something we can assume at this point.
*
* Note! We cannot necessarily trust enmUseTscDelta here because it's
* downgraded after each delta calculation and the delta
* calculations may not be complete yet.
*/
else if (pGip->u32Mode == SUPGIPMODE_INVARIANT_TSC)
{
/** @todo This section of code is never reached atm, consider dropping it later on... */
if (pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED)
{
uint32_t iStartCpuSet = RTMpCpuIdToSetIndex(idCpuStart);
uint32_t iStopCpuSet = RTMpCpuIdToSetIndex(idCpuStop);
uint16_t iStartGipCpu = iStartCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)
? pGip->aiCpuFromCpuSetIdx[iStartCpuSet] : UINT16_MAX;
uint16_t iStopGipCpu = iStopCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)
? pGip->aiCpuFromCpuSetIdx[iStopCpuSet] : UINT16_MAX;
int64_t iStartTscDelta = iStartGipCpu < pGip->cCpus ? pGip->aCPUs[iStartGipCpu].i64TSCDelta : INT64_MAX;
int64_t iStopTscDelta = iStopGipCpu < pGip->cCpus ? pGip->aCPUs[iStopGipCpu].i64TSCDelta : INT64_MAX;
if (RT_LIKELY(iStartTscDelta != INT64_MAX && iStopTscDelta != INT64_MAX))
{
if (pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_PRACTICALLY_ZERO)
{
uTscStart -= iStartTscDelta;
uTscStop -= iStopTscDelta;
}
}
/*
* Invalid CPU indexes are not caused by online/offline races, so
* we have to trigger driver load failure if that happens as GIP
* and IPRT assumptions are busted on this system.
*/
else if (iStopGipCpu >= pGip->cCpus || iStartGipCpu >= pGip->cCpus)
{
SUPR0Printf("vboxdrv: Unexpected CPU index in supdrvGipInitMeasureTscFreq.\n");
SUPR0Printf("vboxdrv: start: %u, %u, %#llx stop: %u, %u, %#llx\n",
iStartCpuSet, iStartGipCpu, iStartTscDelta, iStopCpuSet, iStopGipCpu, iStopTscDelta);
return VERR_INVALID_CPU_INDEX;
}
/*
* No valid deltas. We retry, if we're on our last retry
* we do the cross call instead just to get a result. The
* frequency will be refined in a few seconds anyways.
*/
else if (cTriesLeft > 0)
continue;
else
fDoXCall = true;
}
}
/*
* Asynchronous TSC mode: This is bad as the reason we usually
* use this mode is to deal with variable TSC frequencies and
* deltas. So, we need to get the TSC from the same CPU as
* started it, we also need to keep that CPU busy. So, retry
* and fall back to the cross call on the last attempt.
*/
else
{
Assert(pGip->u32Mode == SUPGIPMODE_ASYNC_TSC);
if (cTriesLeft > 0)
continue;
fDoXCall = true;
}
if (fDoXCall)
{
/*
* Try read the TSC and timestamp on the start CPU.
*/
int rc = RTMpOnSpecific(idCpuStart, supdrvGipInitReadTscAndNanoTsOnCpu, &uTscStop, &nsStop);
if (RT_FAILURE(rc) && (!fRough || cTriesLeft > 0))
continue;
}
}
/*
* Calculate the TSC frequency and update it (shared with the refinement timer).
*/
supdrvGipInitSetCpuFreq(pGip, nsStop - nsStart, uTscStop - uTscStart, 0);
return VINF_SUCCESS;
}
Assert(!fRough);
return VERR_SUPDRV_TSC_FREQ_MEASUREMENT_FAILED;
}
/**
* Finds our (@a idCpu) entry, or allocates a new one if not found.
*
* @returns Index of the CPU in the cache set.
* @param pGip The GIP.
* @param idCpu The CPU ID.
*/
static uint32_t supdrvGipFindOrAllocCpuIndexForCpuId(PSUPGLOBALINFOPAGE pGip, RTCPUID idCpu)
{
uint32_t i, cTries;
/*
* ASSUMES that CPU IDs are constant.
*/
for (i = 0; i < pGip->cCpus; i++)
if (pGip->aCPUs[i].idCpu == idCpu)
return i;
cTries = 0;
do
{
for (i = 0; i < pGip->cCpus; i++)
{
bool fRc;
ASMAtomicCmpXchgSize(&pGip->aCPUs[i].idCpu, idCpu, NIL_RTCPUID, fRc);
if (fRc)
return i;
}
} while (cTries++ < 32);
AssertReleaseFailed();
return i - 1;
}
/**
* The calling CPU should be accounted as online, update GIP accordingly.
*
* This is used by supdrvGipCreate() as well as supdrvGipMpEvent().
*
* @param pDevExt The device extension.
* @param idCpu The CPU ID.
*/
static void supdrvGipMpEventOnlineOrInitOnCpu(PSUPDRVDEVEXT pDevExt, RTCPUID idCpu)
{
int iCpuSet = 0;
uint16_t idApic = UINT16_MAX;
uint32_t i = 0;
uint64_t u64NanoTS = 0;
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
AssertPtrReturnVoid(pGip);
Assert(!RTThreadPreemptIsEnabled(NIL_RTTHREAD));
AssertRelease(idCpu == RTMpCpuId());
Assert(pGip->cPossibleCpus == RTMpGetCount());
/*
* Do this behind a spinlock with interrupts disabled as this can fire
* on all CPUs simultaneously, see @bugref{6110}.
*/
RTSpinlockAcquire(pDevExt->hGipSpinlock);
/*
* Update the globals.
*/
ASMAtomicWriteU16(&pGip->cPresentCpus, RTMpGetPresentCount());
ASMAtomicWriteU16(&pGip->cOnlineCpus, RTMpGetOnlineCount());
iCpuSet = RTMpCpuIdToSetIndex(idCpu);
if (iCpuSet >= 0)
{
Assert(RTCpuSetIsMemberByIndex(&pGip->PossibleCpuSet, iCpuSet));
RTCpuSetAddByIndex(&pGip->OnlineCpuSet, iCpuSet);
RTCpuSetAddByIndex(&pGip->PresentCpuSet, iCpuSet);
}
/*
* Update the entry.
*/
u64NanoTS = RTTimeSystemNanoTS() - pGip->u32UpdateIntervalNS;
i = supdrvGipFindOrAllocCpuIndexForCpuId(pGip, idCpu);
supdrvGipInitCpu(pGip, &pGip->aCPUs[i], u64NanoTS, pGip->u64CpuHz);
idApic = ASMGetApicId();
ASMAtomicWriteU16(&pGip->aCPUs[i].idApic, idApic);
ASMAtomicWriteS16(&pGip->aCPUs[i].iCpuSet, (int16_t)iCpuSet);
ASMAtomicWriteSize(&pGip->aCPUs[i].idCpu, idCpu);
/*
* Update the APIC ID and CPU set index mappings.
*/
ASMAtomicWriteU16(&pGip->aiCpuFromApicId[idApic], i);
ASMAtomicWriteU16(&pGip->aiCpuFromCpuSetIdx[iCpuSet], i);
/* Add this CPU to this set of CPUs we need to calculate the TSC-delta for. */
RTCpuSetAddByIndex(&pDevExt->TscDeltaCpuSet, RTMpCpuIdToSetIndex(idCpu));
/* Update the Mp online/offline counter. */
ASMAtomicIncU32(&pDevExt->cMpOnOffEvents);
/* Commit it. */
ASMAtomicWriteSize(&pGip->aCPUs[i].enmState, SUPGIPCPUSTATE_ONLINE);
RTSpinlockRelease(pDevExt->hGipSpinlock);
}
/**
* RTMpOnSpecific callback wrapper for supdrvGipMpEventOnlineOrInitOnCpu().
*
* @param idCpu The CPU ID we are running on.
* @param pvUser1 Opaque pointer to the device instance data.
* @param pvUser2 Not used.
*/
static DECLCALLBACK(void) supdrvGipMpEventOnlineCallback(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
PSUPDRVDEVEXT pDevExt = (PSUPDRVDEVEXT)pvUser1;
NOREF(pvUser2);
supdrvGipMpEventOnlineOrInitOnCpu(pDevExt, idCpu);
}
/**
* The CPU should be accounted as offline, update the GIP accordingly.
*
* This is used by supdrvGipMpEvent.
*
* @param pDevExt The device extension.
* @param idCpu The CPU ID.
*/
static void supdrvGipMpEventOffline(PSUPDRVDEVEXT pDevExt, RTCPUID idCpu)
{
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
int iCpuSet;
unsigned i;
AssertPtrReturnVoid(pGip);
RTSpinlockAcquire(pDevExt->hGipSpinlock);
iCpuSet = RTMpCpuIdToSetIndex(idCpu);
AssertReturnVoid(iCpuSet >= 0);
i = pGip->aiCpuFromCpuSetIdx[iCpuSet];
AssertReturnVoid(i < pGip->cCpus);
AssertReturnVoid(pGip->aCPUs[i].idCpu == idCpu);
Assert(RTCpuSetIsMemberByIndex(&pGip->PossibleCpuSet, iCpuSet));
RTCpuSetDelByIndex(&pGip->OnlineCpuSet, iCpuSet);
/* Update the Mp online/offline counter. */
ASMAtomicIncU32(&pDevExt->cMpOnOffEvents);
if (pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED)
{
/* Reset the TSC delta, we will recalculate it lazily. */
ASMAtomicWriteS64(&pGip->aCPUs[i].i64TSCDelta, INT64_MAX);
/* Remove this CPU from the set of CPUs that we have obtained the TSC deltas. */
RTCpuSetDelByIndex(&pDevExt->TscDeltaObtainedCpuSet, iCpuSet);
}
/* Commit it. */
ASMAtomicWriteSize(&pGip->aCPUs[i].enmState, SUPGIPCPUSTATE_OFFLINE);
RTSpinlockRelease(pDevExt->hGipSpinlock);
}
/**
* Multiprocessor event notification callback.
*
* This is used to make sure that the GIP master gets passed on to
* another CPU. It also updates the associated CPU data.
*
* @param enmEvent The event.
* @param idCpu The cpu it applies to.
* @param pvUser Pointer to the device extension.
*/
static DECLCALLBACK(void) supdrvGipMpEvent(RTMPEVENT enmEvent, RTCPUID idCpu, void *pvUser)
{
PSUPDRVDEVEXT pDevExt = (PSUPDRVDEVEXT)pvUser;
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
if (pGip)
{
RTTHREADPREEMPTSTATE PreemptState = RTTHREADPREEMPTSTATE_INITIALIZER;
switch (enmEvent)
{
case RTMPEVENT_ONLINE:
{
RTThreadPreemptDisable(&PreemptState);
if (idCpu == RTMpCpuId())
{
supdrvGipMpEventOnlineOrInitOnCpu(pDevExt, idCpu);
RTThreadPreemptRestore(&PreemptState);
}
else
{
RTThreadPreemptRestore(&PreemptState);
RTMpOnSpecific(idCpu, supdrvGipMpEventOnlineCallback, pDevExt, NULL /* pvUser2 */);
}
/*
* Recompute TSC-delta for the newly online'd CPU.
*/
if (pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED)
{
#ifdef SUPDRV_USE_TSC_DELTA_THREAD
supdrvTscDeltaThreadStartMeasurement(pDevExt);
#else
uint32_t iCpu = supdrvGipFindOrAllocCpuIndexForCpuId(pGip, idCpu);
supdrvMeasureTscDeltaOne(pDevExt, iCpu);
#endif
}
break;
}
case RTMPEVENT_OFFLINE:
supdrvGipMpEventOffline(pDevExt, idCpu);
break;
}
}
/*
* Make sure there is a master GIP.
*/
if (enmEvent == RTMPEVENT_OFFLINE)
{
RTCPUID idGipMaster = ASMAtomicReadU32(&pDevExt->idGipMaster);
if (idGipMaster == idCpu)
{
/*
* The GIP master is going offline, find a new one.
*/
bool fIgnored;
unsigned i;
RTCPUID idNewGipMaster = NIL_RTCPUID;
RTCPUSET OnlineCpus;
RTMpGetOnlineSet(&OnlineCpus);
for (i = 0; i < RTCPUSET_MAX_CPUS; i++)
if (RTCpuSetIsMemberByIndex(&OnlineCpus, i))
{
RTCPUID idCurCpu = RTMpCpuIdFromSetIndex(i);
if (idCurCpu != idGipMaster)
{
idNewGipMaster = idCurCpu;
break;
}
}
Log(("supdrvGipMpEvent: Gip master %#lx -> %#lx\n", (long)idGipMaster, (long)idNewGipMaster));
ASMAtomicCmpXchgSize(&pDevExt->idGipMaster, idNewGipMaster, idGipMaster, fIgnored);
NOREF(fIgnored);
}
}
}
/**
* On CPU initialization callback for RTMpOnAll.
*
* @param idCpu The CPU ID.
* @param pvUser1 The device extension.
* @param pvUser2 The GIP.
*/
static DECLCALLBACK(void) supdrvGipInitOnCpu(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
/* This is good enough, even though it will update some of the globals a
bit to much. */
supdrvGipMpEventOnlineOrInitOnCpu((PSUPDRVDEVEXT)pvUser1, idCpu);
}
/**
* Callback used by supdrvDetermineAsyncTSC to read the TSC on a CPU.
*
* @param idCpu Ignored.
* @param pvUser1 Where to put the TSC.
* @param pvUser2 Ignored.
*/
static DECLCALLBACK(void) supdrvGipInitDetermineAsyncTscWorker(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
Assert(RTMpCpuIdToSetIndex(idCpu) == (intptr_t)pvUser2);
ASMAtomicWriteU64((uint64_t volatile *)pvUser1, ASMReadTSC());
}
/**
* Determine if Async GIP mode is required because of TSC drift.
*
* When using the default/normal timer code it is essential that the time stamp counter
* (TSC) runs never backwards, that is, a read operation to the counter should return
* a bigger value than any previous read operation. This is guaranteed by the latest
* AMD CPUs and by newer Intel CPUs which never enter the C2 state (P4). In any other
* case we have to choose the asynchronous timer mode.
*
* @param poffMin Pointer to the determined difference between different
* cores (optional, can be NULL).
* @return false if the time stamp counters appear to be synchronized, true otherwise.
*/
static bool supdrvGipInitDetermineAsyncTsc(uint64_t *poffMin)
{
/*
* Just iterate all the cpus 8 times and make sure that the TSC is
* ever increasing. We don't bother taking TSC rollover into account.
*/
int iEndCpu = RTMpGetArraySize();
int iCpu;
int cLoops = 8;
bool fAsync = false;
int rc = VINF_SUCCESS;
uint64_t offMax = 0;
uint64_t offMin = ~(uint64_t)0;
uint64_t PrevTsc = ASMReadTSC();
while (cLoops-- > 0)
{
for (iCpu = 0; iCpu < iEndCpu; iCpu++)
{
uint64_t CurTsc;
rc = RTMpOnSpecific(RTMpCpuIdFromSetIndex(iCpu), supdrvGipInitDetermineAsyncTscWorker,
&CurTsc, (void *)(uintptr_t)iCpu);
if (RT_SUCCESS(rc))
{
if (CurTsc <= PrevTsc)
{
fAsync = true;
offMin = offMax = PrevTsc - CurTsc;
Log(("supdrvGipInitDetermineAsyncTsc: iCpu=%d cLoops=%d CurTsc=%llx PrevTsc=%llx\n",
iCpu, cLoops, CurTsc, PrevTsc));
break;
}
/* Gather statistics (except the first time). */
if (iCpu != 0 || cLoops != 7)
{
uint64_t off = CurTsc - PrevTsc;
if (off < offMin)
offMin = off;
if (off > offMax)
offMax = off;
Log2(("%d/%d: off=%llx\n", cLoops, iCpu, off));
}
/* Next */
PrevTsc = CurTsc;
}
else if (rc == VERR_NOT_SUPPORTED)
break;
else
AssertMsg(rc == VERR_CPU_NOT_FOUND || rc == VERR_CPU_OFFLINE, ("%d\n", rc));
}
/* broke out of the loop. */
if (iCpu < iEndCpu)
break;
}
if (poffMin)
*poffMin = offMin; /* Almost RTMpOnSpecific profiling. */
Log(("supdrvGipInitDetermineAsyncTsc: returns %d; iEndCpu=%d rc=%d offMin=%llx offMax=%llx\n",
fAsync, iEndCpu, rc, offMin, offMax));
#if !defined(RT_OS_SOLARIS) && !defined(RT_OS_OS2) && !defined(RT_OS_WINDOWS)
OSDBGPRINT(("vboxdrv: fAsync=%d offMin=%#lx offMax=%#lx\n", fAsync, (long)offMin, (long)offMax));
#endif
return fAsync;
}
/**
* supdrvGipInit() worker that determines the GIP TSC mode.
*
* @returns The most suitable TSC mode.
* @param pDevExt Pointer to the device instance data.
*/
static SUPGIPMODE supdrvGipInitDetermineTscMode(PSUPDRVDEVEXT pDevExt)
{
uint64_t u64DiffCoresIgnored;
uint32_t uEAX, uEBX, uECX, uEDX;
/*
* Establish whether the CPU advertises TSC as invariant, we need that in
* a couple of places below.
*/
bool fInvariantTsc = false;
if (ASMHasCpuId())
{
uEAX = ASMCpuId_EAX(0x80000000);
if (ASMIsValidExtRange(uEAX) && uEAX >= 0x80000007)
{
uEDX = ASMCpuId_EDX(0x80000007);
if (uEDX & X86_CPUID_AMD_ADVPOWER_EDX_TSCINVAR)
fInvariantTsc = true;
}
}
/*
* On single CPU systems, we don't need to consider ASYNC mode.
*/
if (RTMpGetCount() <= 1)
return fInvariantTsc ? SUPGIPMODE_INVARIANT_TSC : SUPGIPMODE_SYNC_TSC;
/*
* Allow the user and/or OS specific bits to force async mode.
*/
if (supdrvOSGetForcedAsyncTscMode(pDevExt))
return SUPGIPMODE_ASYNC_TSC;
/*
* Use invariant mode if the CPU says TSC is invariant.
*/
if (fInvariantTsc)
return SUPGIPMODE_INVARIANT_TSC;
/*
* TSC is not invariant and we're on SMP, this presents two problems:
*
* (1) There might be a skew between the CPU, so that cpu0
* returns a TSC that is slightly different from cpu1.
* This screw may be due to (2), bad TSC initialization
* or slightly different TSC rates.
*
* (2) Power management (and other things) may cause the TSC
* to run at a non-constant speed, and cause the speed
* to be different on the cpus. This will result in (1).
*
* If any of the above is detected, we will have to use ASYNC mode.
*/
/* (1). Try check for current differences between the cpus. */
if (supdrvGipInitDetermineAsyncTsc(&u64DiffCoresIgnored))
return SUPGIPMODE_ASYNC_TSC;
/* (2) If it's an AMD CPU with power management, we won't trust its TSC. */
ASMCpuId(0, &uEAX, &uEBX, &uECX, &uEDX);
if ( ASMIsValidStdRange(uEAX)
&& ASMIsAmdCpuEx(uEBX, uECX, uEDX))
{
/* Check for APM support. */
uEAX = ASMCpuId_EAX(0x80000000);
if (ASMIsValidExtRange(uEAX) && uEAX >= 0x80000007)
{
uEDX = ASMCpuId_EDX(0x80000007);
if (uEDX & 0x3e) /* STC|TM|THERMTRIP|VID|FID. Ignore TS. */
return SUPGIPMODE_ASYNC_TSC;
}
}
return SUPGIPMODE_SYNC_TSC;
}
/**
* Initializes per-CPU GIP information.
*
* @param pGip Pointer to the GIP.
* @param pCpu Pointer to which GIP CPU to initalize.
* @param u64NanoTS The current nanosecond timestamp.
* @param uCpuHz The CPU frequency to set, 0 if the caller doesn't know.
*/
static void supdrvGipInitCpu(PSUPGLOBALINFOPAGE pGip, PSUPGIPCPU pCpu, uint64_t u64NanoTS, uint64_t uCpuHz)
{
pCpu->u32TransactionId = 2;
pCpu->u64NanoTS = u64NanoTS;
pCpu->u64TSC = ASMReadTSC();
pCpu->u64TSCSample = GIP_TSC_DELTA_RSVD;
pCpu->i64TSCDelta = pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED ? INT64_MAX : 0;
ASMAtomicWriteSize(&pCpu->enmState, SUPGIPCPUSTATE_INVALID);
ASMAtomicWriteSize(&pCpu->idCpu, NIL_RTCPUID);
ASMAtomicWriteS16(&pCpu->iCpuSet, -1);
ASMAtomicWriteU16(&pCpu->idApic, UINT16_MAX);
/*
* The first time we're called, we don't have a CPU frequency handy,
* so pretend it's a 4 GHz CPU. On CPUs that are online, we'll get
* called again and at that point we have a more plausible CPU frequency
* value handy. The frequency history will also be adjusted again on
* the 2nd timer callout (maybe we can skip that now?).
*/
if (!uCpuHz)
{
pCpu->u64CpuHz = _4G - 1;
pCpu->u32UpdateIntervalTSC = (uint32_t)((_4G - 1) / pGip->u32UpdateHz);
}
else
{
pCpu->u64CpuHz = uCpuHz;
pCpu->u32UpdateIntervalTSC = (uint32_t)(uCpuHz / pGip->u32UpdateHz);
}
pCpu->au32TSCHistory[0]
= pCpu->au32TSCHistory[1]
= pCpu->au32TSCHistory[2]
= pCpu->au32TSCHistory[3]
= pCpu->au32TSCHistory[4]
= pCpu->au32TSCHistory[5]
= pCpu->au32TSCHistory[6]
= pCpu->au32TSCHistory[7]
= pCpu->u32UpdateIntervalTSC;
}
/**
* Initializes the GIP data.
*
* @param pDevExt Pointer to the device instance data.
* @param pGip Pointer to the read-write kernel mapping of the GIP.
* @param HCPhys The physical address of the GIP.
* @param u64NanoTS The current nanosecond timestamp.
* @param uUpdateHz The update frequency.
* @param uUpdateIntervalNS The update interval in nanoseconds.
* @param cCpus The CPU count.
*/
static void supdrvGipInit(PSUPDRVDEVEXT pDevExt, PSUPGLOBALINFOPAGE pGip, RTHCPHYS HCPhys,
uint64_t u64NanoTS, unsigned uUpdateHz, unsigned uUpdateIntervalNS, unsigned cCpus)
{
size_t const cbGip = RT_ALIGN_Z(RT_OFFSETOF(SUPGLOBALINFOPAGE, aCPUs[cCpus]), PAGE_SIZE);
unsigned i;
#ifdef DEBUG_DARWIN_GIP
OSDBGPRINT(("supdrvGipInit: pGip=%p HCPhys=%lx u64NanoTS=%llu uUpdateHz=%d cCpus=%u\n", pGip, (long)HCPhys, u64NanoTS, uUpdateHz, cCpus));
#else
LogFlow(("supdrvGipInit: pGip=%p HCPhys=%lx u64NanoTS=%llu uUpdateHz=%d cCpus=%u\n", pGip, (long)HCPhys, u64NanoTS, uUpdateHz, cCpus));
#endif
/*
* Initialize the structure.
*/
memset(pGip, 0, cbGip);
pGip->u32Magic = SUPGLOBALINFOPAGE_MAGIC;
pGip->u32Version = SUPGLOBALINFOPAGE_VERSION;
pGip->u32Mode = supdrvGipInitDetermineTscMode(pDevExt);
if ( pGip->u32Mode == SUPGIPMODE_INVARIANT_TSC
/*|| pGip->u32Mode == SUPGIPMODE_SYNC_TSC */)
pGip->enmUseTscDelta = supdrvOSAreTscDeltasInSync() /* Allow OS override (windows). */
? SUPGIPUSETSCDELTA_ZERO_CLAIMED : SUPGIPUSETSCDELTA_PRACTICALLY_ZERO /* downgrade later */;
else
pGip->enmUseTscDelta = SUPGIPUSETSCDELTA_NOT_APPLICABLE;
pGip->cCpus = (uint16_t)cCpus;
pGip->cPages = (uint16_t)(cbGip / PAGE_SIZE);
pGip->u32UpdateHz = uUpdateHz;
pGip->u32UpdateIntervalNS = uUpdateIntervalNS;
pGip->fGetGipCpu = SUPGIPGETCPU_APIC_ID;
RTCpuSetEmpty(&pGip->OnlineCpuSet);
RTCpuSetEmpty(&pGip->PresentCpuSet);
RTMpGetSet(&pGip->PossibleCpuSet);
pGip->cOnlineCpus = RTMpGetOnlineCount();
pGip->cPresentCpus = RTMpGetPresentCount();
pGip->cPossibleCpus = RTMpGetCount();
pGip->idCpuMax = RTMpGetMaxCpuId();
for (i = 0; i < RT_ELEMENTS(pGip->aiCpuFromApicId); i++)
pGip->aiCpuFromApicId[i] = UINT16_MAX;
for (i = 0; i < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx); i++)
pGip->aiCpuFromCpuSetIdx[i] = UINT16_MAX;
for (i = 0; i < cCpus; i++)
supdrvGipInitCpu(pGip, &pGip->aCPUs[i], u64NanoTS, 0 /*uCpuHz*/);
/*
* Link it to the device extension.
*/
pDevExt->pGip = pGip;
pDevExt->HCPhysGip = HCPhys;
pDevExt->cGipUsers = 0;
}
/**
* Creates the GIP.
*
* @returns VBox status code.
* @param pDevExt Instance data. GIP stuff may be updated.
*/
int VBOXCALL supdrvGipCreate(PSUPDRVDEVEXT pDevExt)
{
PSUPGLOBALINFOPAGE pGip;
RTHCPHYS HCPhysGip;
uint32_t u32SystemResolution;
uint32_t u32Interval;
uint32_t u32MinInterval;
uint32_t uMod;
unsigned cCpus;
int rc;
LogFlow(("supdrvGipCreate:\n"));
/*
* Assert order.
*/
Assert(pDevExt->u32SystemTimerGranularityGrant == 0);
Assert(pDevExt->GipMemObj == NIL_RTR0MEMOBJ);
Assert(!pDevExt->pGipTimer);
#ifdef SUPDRV_USE_MUTEX_FOR_GIP
Assert(pDevExt->mtxGip != NIL_RTSEMMUTEX);
Assert(pDevExt->mtxTscDelta != NIL_RTSEMMUTEX);
#else
Assert(pDevExt->mtxGip != NIL_RTSEMFASTMUTEX);
Assert(pDevExt->mtxTscDelta != NIL_RTSEMFASTMUTEX);
#endif
/*
* Check the CPU count.
*/
cCpus = RTMpGetArraySize();
if ( cCpus > RTCPUSET_MAX_CPUS
|| cCpus > 256 /* ApicId is used for the mappings */)
{
SUPR0Printf("VBoxDrv: Too many CPUs (%u) for the GIP (max %u)\n", cCpus, RT_MIN(RTCPUSET_MAX_CPUS, 256));
return VERR_TOO_MANY_CPUS;
}
/*
* Allocate a contiguous set of pages with a default kernel mapping.
*/
rc = RTR0MemObjAllocCont(&pDevExt->GipMemObj, RT_UOFFSETOF(SUPGLOBALINFOPAGE, aCPUs[cCpus]), false /*fExecutable*/);
if (RT_FAILURE(rc))
{
OSDBGPRINT(("supdrvGipCreate: failed to allocate the GIP page. rc=%d\n", rc));
return rc;
}
pGip = (PSUPGLOBALINFOPAGE)RTR0MemObjAddress(pDevExt->GipMemObj); AssertPtr(pGip);
HCPhysGip = RTR0MemObjGetPagePhysAddr(pDevExt->GipMemObj, 0); Assert(HCPhysGip != NIL_RTHCPHYS);
/*
* Find a reasonable update interval and initialize the structure.
*/
supdrvGipRequestHigherTimerFrequencyFromSystem(pDevExt);
/** @todo figure out why using a 100Ms interval upsets timekeeping in VMs.
* See @bugref{6710}. */
u32MinInterval = RT_NS_10MS;
u32SystemResolution = RTTimerGetSystemGranularity();
u32Interval = u32MinInterval;
uMod = u32MinInterval % u32SystemResolution;
if (uMod)
u32Interval += u32SystemResolution - uMod;
supdrvGipInit(pDevExt, pGip, HCPhysGip, RTTimeSystemNanoTS(), RT_NS_1SEC / u32Interval /*=Hz*/, u32Interval, cCpus);
/*
* Important sanity check...
*/
if (RT_UNLIKELY( pGip->enmUseTscDelta == SUPGIPUSETSCDELTA_ZERO_CLAIMED
&& pGip->u32Mode == SUPGIPMODE_ASYNC_TSC
&& !supdrvOSGetForcedAsyncTscMode(pDevExt)))
{
/* Basically, invariant Windows boxes, should never be detected as async (i.e. TSC-deltas should be 0). */
OSDBGPRINT(("supdrvGipCreate: The TSC-deltas should be normalized by the host OS, but verifying shows it's not!\n"));
return VERR_INTERNAL_ERROR_2;
}
/*
* Do the TSC frequency measurements.
*
* If we're in invariant TSC mode, just to a quick preliminary measurement
* that the TSC-delta measurement code can use to yield cross calls.
*
* If we're in any of the other two modes, neither which require MP init,
* notifications or deltas for the job, do the full measurement now so
* that supdrvGipInitOnCpu() can populate the TSC interval and history
* array with more reasonable values.
*/
if (pGip->u32Mode == SUPGIPMODE_INVARIANT_TSC)
{
rc = supdrvGipInitMeasureTscFreq(pDevExt, pGip, true /*fRough*/); /* cannot fail */
supdrvGipInitStartTimerForRefiningInvariantTscFreq(pDevExt, pGip);
}
else
rc = supdrvGipInitMeasureTscFreq(pDevExt, pGip, false /*fRough*/);
if (RT_SUCCESS(rc))
{
/*
* Start TSC-delta measurement thread before we start getting MP
* events that will try kick it into action (includes the
* RTMpOnAll/supdrvGipInitOnCpu call below).
*/
RTCpuSetEmpty(&pDevExt->TscDeltaCpuSet);
RTCpuSetEmpty(&pDevExt->TscDeltaObtainedCpuSet);
#ifdef SUPDRV_USE_TSC_DELTA_THREAD
if ( pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED
&& pGip->u32Mode == SUPGIPMODE_INVARIANT_TSC)
rc = supdrvTscDeltaThreadInit(pDevExt);
#endif
if (RT_SUCCESS(rc))
{
rc = RTMpNotificationRegister(supdrvGipMpEvent, pDevExt);
if (RT_SUCCESS(rc))
{
/*
* Do GIP initialization on all online CPUs. Wake up the
* TSC-delta thread afterwards.
*/
rc = RTMpOnAll(supdrvGipInitOnCpu, pDevExt, pGip);
if (RT_SUCCESS(rc))
{
#ifdef SUPDRV_USE_TSC_DELTA_THREAD
supdrvTscDeltaThreadStartMeasurement(pDevExt);
#else
uint16_t iCpu;
if (pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED)
{
/*
* Measure the TSC deltas now that we have MP notifications.
*/
int cTries = 5;
do
{
rc = supdrvMeasureInitialTscDeltas(pDevExt);
if ( rc != VERR_TRY_AGAIN
&& rc != VERR_CPU_OFFLINE)
break;
} while (--cTries > 0);
for (iCpu = 0; iCpu < pGip->cCpus; iCpu++)
Log(("supdrvTscDeltaInit: cpu[%u] delta %lld\n", iCpu, pGip->aCPUs[iCpu].i64TSCDelta));
}
else
{
for (iCpu = 0; iCpu < pGip->cCpus; iCpu++)
AssertMsg(!pGip->aCPUs[iCpu].i64TSCDelta, ("iCpu=%u %lld mode=%d\n", iCpu, pGip->aCPUs[iCpu].i64TSCDelta, pGip->u32Mode));
}
if (RT_SUCCESS(rc))
#endif
{
/*
* Create the timer.
* If CPU_ALL isn't supported we'll have to fall back to synchronous mode.
*/
if (pGip->u32Mode == SUPGIPMODE_ASYNC_TSC)
{
rc = RTTimerCreateEx(&pDevExt->pGipTimer, u32Interval, RTTIMER_FLAGS_CPU_ALL,
supdrvGipAsyncTimer, pDevExt);
if (rc == VERR_NOT_SUPPORTED)
{
OSDBGPRINT(("supdrvGipCreate: omni timer not supported, falling back to synchronous mode\n"));
pGip->u32Mode = SUPGIPMODE_SYNC_TSC;
}
}
if (pGip->u32Mode != SUPGIPMODE_ASYNC_TSC)
rc = RTTimerCreateEx(&pDevExt->pGipTimer, u32Interval, 0 /* fFlags */,
supdrvGipSyncAndInvariantTimer, pDevExt);
if (RT_SUCCESS(rc))
{
/*
* We're good.
*/
Log(("supdrvGipCreate: %u ns interval.\n", u32Interval));
supdrvGipReleaseHigherTimerFrequencyFromSystem(pDevExt);
g_pSUPGlobalInfoPage = pGip;
return VINF_SUCCESS;
}
OSDBGPRINT(("supdrvGipCreate: failed create GIP timer at %u ns interval. rc=%Rrc\n", u32Interval, rc));
Assert(!pDevExt->pGipTimer);
}
}
else
OSDBGPRINT(("supdrvGipCreate: RTMpOnAll failed. rc=%Rrc\n", rc));
}
else
OSDBGPRINT(("supdrvGipCreate: failed to register MP event notfication. rc=%Rrc\n", rc));
}
else
OSDBGPRINT(("supdrvGipCreate: supdrvTscDeltaInit failed. rc=%Rrc\n", rc));
}
else
OSDBGPRINT(("supdrvGipCreate: supdrvMeasureInitialTscDeltas failed. rc=%Rrc\n", rc));
/* Releases timer frequency increase too. */
supdrvGipDestroy(pDevExt);
return rc;
}
/**
* Invalidates the GIP data upon termination.
*
* @param pGip Pointer to the read-write kernel mapping of the GIP.
*/
static void supdrvGipTerm(PSUPGLOBALINFOPAGE pGip)
{
unsigned i;
pGip->u32Magic = 0;
for (i = 0; i < pGip->cCpus; i++)
{
pGip->aCPUs[i].u64NanoTS = 0;
pGip->aCPUs[i].u64TSC = 0;
pGip->aCPUs[i].iTSCHistoryHead = 0;
pGip->aCPUs[i].u64TSCSample = 0;
pGip->aCPUs[i].i64TSCDelta = INT64_MAX;
}
}
/**
* Terminates the GIP.
*
* @param pDevExt Instance data. GIP stuff may be updated.
*/
void VBOXCALL supdrvGipDestroy(PSUPDRVDEVEXT pDevExt)
{
int rc;
#ifdef DEBUG_DARWIN_GIP
OSDBGPRINT(("supdrvGipDestroy: pDevExt=%p pGip=%p pGipTimer=%p GipMemObj=%p\n", pDevExt,
pDevExt->GipMemObj != NIL_RTR0MEMOBJ ? RTR0MemObjAddress(pDevExt->GipMemObj) : NULL,
pDevExt->pGipTimer, pDevExt->GipMemObj));
#endif
/*
* Stop receiving MP notifications before tearing anything else down.
*/
RTMpNotificationDeregister(supdrvGipMpEvent, pDevExt);
#ifdef SUPDRV_USE_TSC_DELTA_THREAD
/*
* Terminate the TSC-delta measurement thread and resources.
*/
supdrvTscDeltaTerm(pDevExt);
#endif
/*
* Destroy the TSC-refinement timer.
*/
if (pDevExt->pInvarTscRefineTimer)
{
RTTimerDestroy(pDevExt->pInvarTscRefineTimer);
pDevExt->pInvarTscRefineTimer = NULL;
}
/*
* Invalid the GIP data.
*/
if (pDevExt->pGip)
{
supdrvGipTerm(pDevExt->pGip);
pDevExt->pGip = NULL;
}
g_pSUPGlobalInfoPage = NULL;
/*
* Destroy the timer and free the GIP memory object.
*/
if (pDevExt->pGipTimer)
{
rc = RTTimerDestroy(pDevExt->pGipTimer); AssertRC(rc);
pDevExt->pGipTimer = NULL;
}
if (pDevExt->GipMemObj != NIL_RTR0MEMOBJ)
{
rc = RTR0MemObjFree(pDevExt->GipMemObj, true /* free mappings */); AssertRC(rc);
pDevExt->GipMemObj = NIL_RTR0MEMOBJ;
}
/*
* Finally, make sure we've release the system timer resolution request
* if one actually succeeded and is still pending.
*/
supdrvGipReleaseHigherTimerFrequencyFromSystem(pDevExt);
}
/*
*
*
* GIP Update Timer Related Code
* GIP Update Timer Related Code
* GIP Update Timer Related Code
*
*
*/
/**
* Worker routine for supdrvGipUpdate() and supdrvGipUpdatePerCpu() that
* updates all the per cpu data except the transaction id.
*
* @param pDevExt The device extension.
* @param pGipCpu Pointer to the per cpu data.
* @param u64NanoTS The current time stamp.
* @param u64TSC The current TSC.
* @param iTick The current timer tick.
*
* @remarks Can be called with interrupts disabled!
*/
static void supdrvGipDoUpdateCpu(PSUPDRVDEVEXT pDevExt, PSUPGIPCPU pGipCpu, uint64_t u64NanoTS, uint64_t u64TSC, uint64_t iTick)
{
uint64_t u64TSCDelta;
uint32_t u32UpdateIntervalTSC;
uint32_t u32UpdateIntervalTSCSlack;
unsigned iTSCHistoryHead;
uint64_t u64CpuHz;
uint32_t u32TransactionId;
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
AssertPtrReturnVoid(pGip);
/* Delta between this and the previous update. */
ASMAtomicUoWriteU32(&pGipCpu->u32PrevUpdateIntervalNS, (uint32_t)(u64NanoTS - pGipCpu->u64NanoTS));
/*
* Update the NanoTS.
*/
ASMAtomicWriteU64(&pGipCpu->u64NanoTS, u64NanoTS);
/*
* Calc TSC delta.
*/
u64TSCDelta = u64TSC - pGipCpu->u64TSC;
ASMAtomicWriteU64(&pGipCpu->u64TSC, u64TSC);
/*
* We don't need to keep realculating the frequency when it's invariant, so
* the remainder of this function is only for the sync and async TSC modes.
*/
if (pGip->u32Mode != SUPGIPMODE_INVARIANT_TSC)
{
if (u64TSCDelta >> 32)
{
u64TSCDelta = pGipCpu->u32UpdateIntervalTSC;
pGipCpu->cErrors++;
}
/*
* On the 2nd and 3rd callout, reset the history with the current TSC
* interval since the values entered by supdrvGipInit are totally off.
* The interval on the 1st callout completely unreliable, the 2nd is a bit
* better, while the 3rd should be most reliable.
*/
/** @todo Could we drop this now that we initializes the history
* with nominal TSC frequency values? */
u32TransactionId = pGipCpu->u32TransactionId;
if (RT_UNLIKELY( ( u32TransactionId == 5
|| u32TransactionId == 7)
&& ( iTick == 2
|| iTick == 3) ))
{
unsigned i;
for (i = 0; i < RT_ELEMENTS(pGipCpu->au32TSCHistory); i++)
ASMAtomicUoWriteU32(&pGipCpu->au32TSCHistory[i], (uint32_t)u64TSCDelta);
}
/*
* Validate the NanoTS deltas between timer fires with an arbitrary threshold of 0.5%.
* Wait until we have at least one full history since the above history reset. The
* assumption is that the majority of the previous history values will be tolerable.
* See @bugref{6710} comment #67.
*/
/** @todo Could we drop the fuding there now that we initializes the history
* with nominal TSC frequency values? */
if ( u32TransactionId > 23 /* 7 + (8 * 2) */
&& pGip->u32Mode != SUPGIPMODE_ASYNC_TSC)
{
uint32_t uNanoTsThreshold = pGip->u32UpdateIntervalNS / 200;
if ( pGipCpu->u32PrevUpdateIntervalNS > pGip->u32UpdateIntervalNS + uNanoTsThreshold
|| pGipCpu->u32PrevUpdateIntervalNS < pGip->u32UpdateIntervalNS - uNanoTsThreshold)
{
uint32_t u32;
u32 = pGipCpu->au32TSCHistory[0];
u32 += pGipCpu->au32TSCHistory[1];
u32 += pGipCpu->au32TSCHistory[2];
u32 += pGipCpu->au32TSCHistory[3];
u32 >>= 2;
u64TSCDelta = pGipCpu->au32TSCHistory[4];
u64TSCDelta += pGipCpu->au32TSCHistory[5];
u64TSCDelta += pGipCpu->au32TSCHistory[6];
u64TSCDelta += pGipCpu->au32TSCHistory[7];
u64TSCDelta >>= 2;
u64TSCDelta += u32;
u64TSCDelta >>= 1;
}
}
/*
* TSC History.
*/
Assert(RT_ELEMENTS(pGipCpu->au32TSCHistory) == 8);
iTSCHistoryHead = (pGipCpu->iTSCHistoryHead + 1) & 7;
ASMAtomicWriteU32(&pGipCpu->iTSCHistoryHead, iTSCHistoryHead);
ASMAtomicWriteU32(&pGipCpu->au32TSCHistory[iTSCHistoryHead], (uint32_t)u64TSCDelta);
/*
* UpdateIntervalTSC = average of last 8,2,1 intervals depending on update HZ.
*
* On Windows, we have an occasional (but recurring) sour value that messed up
* the history but taking only 1 interval reduces the precision overall.
*/
if ( pGip->u32Mode == SUPGIPMODE_INVARIANT_TSC
|| pGip->u32UpdateHz >= 1000)
{
uint32_t u32;
u32 = pGipCpu->au32TSCHistory[0];
u32 += pGipCpu->au32TSCHistory[1];
u32 += pGipCpu->au32TSCHistory[2];
u32 += pGipCpu->au32TSCHistory[3];
u32 >>= 2;
u32UpdateIntervalTSC = pGipCpu->au32TSCHistory[4];
u32UpdateIntervalTSC += pGipCpu->au32TSCHistory[5];
u32UpdateIntervalTSC += pGipCpu->au32TSCHistory[6];
u32UpdateIntervalTSC += pGipCpu->au32TSCHistory[7];
u32UpdateIntervalTSC >>= 2;
u32UpdateIntervalTSC += u32;
u32UpdateIntervalTSC >>= 1;
/* Value chosen for a 2GHz Athlon64 running linux 2.6.10/11. */
u32UpdateIntervalTSCSlack = u32UpdateIntervalTSC >> 14;
}
else if (pGip->u32UpdateHz >= 90)
{
u32UpdateIntervalTSC = (uint32_t)u64TSCDelta;
u32UpdateIntervalTSC += pGipCpu->au32TSCHistory[(iTSCHistoryHead - 1) & 7];
u32UpdateIntervalTSC >>= 1;
/* value chosen on a 2GHz thinkpad running windows */
u32UpdateIntervalTSCSlack = u32UpdateIntervalTSC >> 7;
}
else
{
u32UpdateIntervalTSC = (uint32_t)u64TSCDelta;
/* This value hasn't be checked yet.. waiting for OS/2 and 33Hz timers.. :-) */
u32UpdateIntervalTSCSlack = u32UpdateIntervalTSC >> 6;
}
ASMAtomicWriteU32(&pGipCpu->u32UpdateIntervalTSC, u32UpdateIntervalTSC + u32UpdateIntervalTSCSlack);
/*
* CpuHz.
*/
u64CpuHz = ASMMult2xU32RetU64(u32UpdateIntervalTSC, RT_NS_1SEC);
u64CpuHz /= pGip->u32UpdateIntervalNS;
ASMAtomicWriteU64(&pGipCpu->u64CpuHz, u64CpuHz);
}
}
/**
* Updates the GIP.
*
* @param pDevExt The device extension.
* @param u64NanoTS The current nanosecond timesamp.
* @param u64TSC The current TSC timesamp.
* @param idCpu The CPU ID.
* @param iTick The current timer tick.
*
* @remarks Can be called with interrupts disabled!
*/
static void supdrvGipUpdate(PSUPDRVDEVEXT pDevExt, uint64_t u64NanoTS, uint64_t u64TSC, RTCPUID idCpu, uint64_t iTick)
{
/*
* Determine the relevant CPU data.
*/
PSUPGIPCPU pGipCpu;
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
AssertPtrReturnVoid(pGip);
if (pGip->u32Mode != SUPGIPMODE_ASYNC_TSC)
pGipCpu = &pGip->aCPUs[0];
else
{
unsigned iCpu = pGip->aiCpuFromApicId[ASMGetApicId()];
if (RT_UNLIKELY(iCpu >= pGip->cCpus))
return;
pGipCpu = &pGip->aCPUs[iCpu];
if (RT_UNLIKELY(pGipCpu->idCpu != idCpu))
return;
}
/*
* Start update transaction.
*/
if (!(ASMAtomicIncU32(&pGipCpu->u32TransactionId) & 1))
{
/* this can happen on win32 if we're taking to long and there are more CPUs around. shouldn't happen though. */
AssertMsgFailed(("Invalid transaction id, %#x, not odd!\n", pGipCpu->u32TransactionId));
ASMAtomicIncU32(&pGipCpu->u32TransactionId);
pGipCpu->cErrors++;
return;
}
/*
* Recalc the update frequency every 0x800th time.
*/
if ( pGip->u32Mode != SUPGIPMODE_INVARIANT_TSC /* cuz we're not recalculating the frequency on invariants hosts. */
&& !(pGipCpu->u32TransactionId & (GIP_UPDATEHZ_RECALC_FREQ * 2 - 2)))
{
if (pGip->u64NanoTSLastUpdateHz)
{
#ifdef RT_ARCH_AMD64 /** @todo fix 64-bit div here to work on x86 linux. */
uint64_t u64Delta = u64NanoTS - pGip->u64NanoTSLastUpdateHz;
uint32_t u32UpdateHz = (uint32_t)((RT_NS_1SEC_64 * GIP_UPDATEHZ_RECALC_FREQ) / u64Delta);
if (u32UpdateHz <= 2000 && u32UpdateHz >= 30)
{
/** @todo r=ramshankar: Changing u32UpdateHz might screw up TSC frequency
* calculation on non-invariant hosts if it changes the history decision
* taken in supdrvGipDoUpdateCpu(). */
uint64_t u64Interval = u64Delta / GIP_UPDATEHZ_RECALC_FREQ;
ASMAtomicWriteU32(&pGip->u32UpdateHz, u32UpdateHz);
ASMAtomicWriteU32(&pGip->u32UpdateIntervalNS, (uint32_t)u64Interval);
}
#endif
}
ASMAtomicWriteU64(&pGip->u64NanoTSLastUpdateHz, u64NanoTS | 1);
}
/*
* Update the data.
*/
supdrvGipDoUpdateCpu(pDevExt, pGipCpu, u64NanoTS, u64TSC, iTick);
/*
* Complete transaction.
*/
ASMAtomicIncU32(&pGipCpu->u32TransactionId);
}
/**
* Updates the per cpu GIP data for the calling cpu.
*
* @param pDevExt The device extension.
* @param u64NanoTS The current nanosecond timesamp.
* @param u64TSC The current TSC timesamp.
* @param idCpu The CPU ID.
* @param idApic The APIC id for the CPU index.
* @param iTick The current timer tick.
*
* @remarks Can be called with interrupts disabled!
*/
static void supdrvGipUpdatePerCpu(PSUPDRVDEVEXT pDevExt, uint64_t u64NanoTS, uint64_t u64TSC,
RTCPUID idCpu, uint8_t idApic, uint64_t iTick)
{
uint32_t iCpu;
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
/*
* Avoid a potential race when a CPU online notification doesn't fire on
* the onlined CPU but the tick creeps in before the event notification is
* run.
*/
if (RT_UNLIKELY(iTick == 1))
{
iCpu = supdrvGipFindOrAllocCpuIndexForCpuId(pGip, idCpu);
if (pGip->aCPUs[iCpu].enmState == SUPGIPCPUSTATE_OFFLINE)
supdrvGipMpEventOnlineOrInitOnCpu(pDevExt, idCpu);
}
iCpu = pGip->aiCpuFromApicId[idApic];
if (RT_LIKELY(iCpu < pGip->cCpus))
{
PSUPGIPCPU pGipCpu = &pGip->aCPUs[iCpu];
if (pGipCpu->idCpu == idCpu)
{
/*
* Start update transaction.
*/
if (!(ASMAtomicIncU32(&pGipCpu->u32TransactionId) & 1))
{
AssertMsgFailed(("Invalid transaction id, %#x, not odd!\n", pGipCpu->u32TransactionId));
ASMAtomicIncU32(&pGipCpu->u32TransactionId);
pGipCpu->cErrors++;
return;
}
/*
* Update the data.
*/
supdrvGipDoUpdateCpu(pDevExt, pGipCpu, u64NanoTS, u64TSC, iTick);
/*
* Complete transaction.
*/
ASMAtomicIncU32(&pGipCpu->u32TransactionId);
}
}
}
/**
* Timer callback function for the sync and invariant GIP modes.
*
* @param pTimer The timer.
* @param pvUser Opaque pointer to the device extension.
* @param iTick The timer tick.
*/
static DECLCALLBACK(void) supdrvGipSyncAndInvariantTimer(PRTTIMER pTimer, void *pvUser, uint64_t iTick)
{
PSUPDRVDEVEXT pDevExt = (PSUPDRVDEVEXT)pvUser;
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
RTCCUINTREG fOldFlags = ASMIntDisableFlags(); /* No interruptions please (real problem on S10). */
uint64_t u64TSC = ASMReadTSC();
uint64_t u64NanoTS = RTTimeSystemNanoTS();
if (pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_PRACTICALLY_ZERO)
{
/*
* The calculations in supdrvGipUpdate() is somewhat timing sensitive,
* missing timer ticks is not an option for GIP because the GIP users
* will end up incrementing the time in 1ns per time getter call until
* there is a complete timer update. So, if the delta has yet to be
* calculated, we just pretend it is zero for now (the GIP users
* probably won't have it for a wee while either and will do the same).
*
* We could maybe on some platforms try cross calling a CPU with a
* working delta here, but it's not worth the hassle since the
* likelyhood of this happening is really low. On Windows, Linux, and
* Solaris timers fire on the CPU they were registered/started on.
* Darwin timers doesn't necessarily (they are high priority threads).
*/
uint32_t iCpuSet = RTMpCpuIdToSetIndex(RTMpCpuId());
uint16_t iGipCpu = RT_LIKELY(iCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx))
? pGip->aiCpuFromCpuSetIdx[iCpuSet] : UINT16_MAX;
Assert(!ASMIntAreEnabled());
if (RT_LIKELY(iGipCpu < pGip->cCpus))
{
int64_t iTscDelta = pGip->aCPUs[iGipCpu].i64TSCDelta;
if (iTscDelta != INT64_MAX)
u64TSC -= iTscDelta;
}
}
supdrvGipUpdate(pDevExt, u64NanoTS, u64TSC, NIL_RTCPUID, iTick);
ASMSetFlags(fOldFlags);
}
/**
* Timer callback function for async GIP mode.
* @param pTimer The timer.
* @param pvUser Opaque pointer to the device extension.
* @param iTick The timer tick.
*/
static DECLCALLBACK(void) supdrvGipAsyncTimer(PRTTIMER pTimer, void *pvUser, uint64_t iTick)
{
PSUPDRVDEVEXT pDevExt = (PSUPDRVDEVEXT)pvUser;
RTCCUINTREG fOldFlags = ASMIntDisableFlags(); /* No interruptions please (real problem on S10). */
RTCPUID idCpu = RTMpCpuId();
uint64_t u64TSC = ASMReadTSC();
uint64_t NanoTS = RTTimeSystemNanoTS();
/** @todo reset the transaction number and whatnot when iTick == 1. */
if (pDevExt->idGipMaster == idCpu)
supdrvGipUpdate(pDevExt, NanoTS, u64TSC, idCpu, iTick);
else
supdrvGipUpdatePerCpu(pDevExt, NanoTS, u64TSC, idCpu, ASMGetApicId(), iTick);
ASMSetFlags(fOldFlags);
}
/*
*
*
* TSC Delta Measurements And Related Code
* TSC Delta Measurements And Related Code
* TSC Delta Measurements And Related Code
*
*
*/
/*
* Select TSC delta measurement algorithm.
*/
#if 0
# define GIP_TSC_DELTA_METHOD_1
#else
# define GIP_TSC_DELTA_METHOD_2
#endif
/** For padding variables to keep them away from other cache lines. Better too
* large than too small!
* @remarks Current AMD64 and x86 CPUs seems to use 64 bytes. There are claims
* that NetBurst had 128 byte cache lines while the 486 thru Pentium
* III had 32 bytes cache lines. */
#define GIP_TSC_DELTA_CACHE_LINE_SIZE 128
/**
* TSC delta measurment algorithm \#2 result entry.
*/
typedef struct SUPDRVTSCDELTAMETHOD2ENTRY
{
uint32_t iSeqMine;
uint32_t iSeqOther;
uint64_t uTsc;
} SUPDRVTSCDELTAMETHOD2ENTRY;
/**
* TSC delta measurment algorithm \#2 Data.
*/
typedef struct SUPDRVTSCDELTAMETHOD2
{
/** Padding to make sure the iCurSeqNo is in its own cache line. */
uint64_t au64CacheLinePaddingBefore[GIP_TSC_DELTA_CACHE_LINE_SIZE / sizeof(uint64_t)];
/** The current sequence number of this worker. */
uint32_t volatile iCurSeqNo;
/** Padding to make sure the iCurSeqNo is in its own cache line. */
uint32_t au64CacheLinePaddingAfter[GIP_TSC_DELTA_CACHE_LINE_SIZE / sizeof(uint32_t) - 1];
/** Result table. */
SUPDRVTSCDELTAMETHOD2ENTRY aResults[64];
} SUPDRVTSCDELTAMETHOD2;
/** Pointer to the data for TSC delta mesurment algorithm \#2 .*/
typedef SUPDRVTSCDELTAMETHOD2 *PSUPDRVTSCDELTAMETHOD2;
/**
* The TSC delta synchronization struct, version 2.
*
* The syncrhonization variable is completely isolated in its own cache line
* (provided our max cache line size estimate is correct).
*/
typedef struct SUPTSCDELTASYNC2
{
/** Padding to make sure the uVar1 is in its own cache line. */
uint64_t au64CacheLinePaddingBefore[GIP_TSC_DELTA_CACHE_LINE_SIZE / sizeof(uint64_t)];
/** The synchronization variable, holds values GIP_TSC_DELTA_SYNC_*. */
volatile uint32_t uSyncVar;
/** Sequence synchronizing variable used for post 'GO' synchronization. */
volatile uint32_t uSyncSeq;
/** Padding to make sure the uVar1 is in its own cache line. */
uint64_t au64CacheLinePaddingAfter[GIP_TSC_DELTA_CACHE_LINE_SIZE / sizeof(uint64_t) - 2];
/** Start RDTSC value. Put here mainly to save stack space. */
uint64_t uTscStart;
/** Copy of SUPDRVGIPTSCDELTARGS::cMaxTscTicks. */
uint64_t cMaxTscTicks;
} SUPTSCDELTASYNC2;
AssertCompileSize(SUPTSCDELTASYNC2, GIP_TSC_DELTA_CACHE_LINE_SIZE * 2 + sizeof(uint64_t));
typedef SUPTSCDELTASYNC2 *PSUPTSCDELTASYNC2;
/** Prestart wait. */
#define GIP_TSC_DELTA_SYNC2_PRESTART_WAIT UINT32_C(0x0ffe)
/** Prestart aborted. */
#define GIP_TSC_DELTA_SYNC2_PRESTART_ABORT UINT32_C(0x0fff)
/** Ready (on your mark). */
#define GIP_TSC_DELTA_SYNC2_READY UINT32_C(0x1000)
/** Steady (get set). */
#define GIP_TSC_DELTA_SYNC2_STEADY UINT32_C(0x1001)
/** Go! */
#define GIP_TSC_DELTA_SYNC2_GO UINT32_C(0x1002)
/** Used by the verfication test. */
#define GIP_TSC_DELTA_SYNC2_GO_GO UINT32_C(0x1003)
/** We reached the time limit. */
#define GIP_TSC_DELTA_SYNC2_TIMEOUT UINT32_C(0x1ffe)
/** The other party won't touch the sync struct ever again. */
#define GIP_TSC_DELTA_SYNC2_FINAL UINT32_C(0x1fff)
/**
* Argument package/state passed by supdrvMeasureTscDeltaOne() to the RTMpOn
* callback worker.
* @todo add
*/
typedef struct SUPDRVGIPTSCDELTARGS
{
/** The device extension. */
PSUPDRVDEVEXT pDevExt;
/** Pointer to the GIP CPU array entry for the worker. */
PSUPGIPCPU pWorker;
/** Pointer to the GIP CPU array entry for the master. */
PSUPGIPCPU pMaster;
/** The maximum number of ticks to spend in supdrvMeasureTscDeltaCallback.
* (This is what we need a rough TSC frequency for.) */
uint64_t cMaxTscTicks;
/** Used to abort synchronization setup. */
bool volatile fAbortSetup;
/** Padding to make sure the master variables live in its own cache lines. */
uint64_t au64CacheLinePaddingBefore[GIP_TSC_DELTA_CACHE_LINE_SIZE / sizeof(uint64_t)];
/** @name Master
* @{ */
/** The time the master spent in the MP worker. */
uint64_t cElapsedMasterTscTicks;
/** The iTry value when stopped at. */
uint32_t iTry;
/** Set if the run timed out. */
bool volatile fTimedOut;
/** Pointer to the master's synchronization struct (on stack). */
PSUPTSCDELTASYNC2 volatile pSyncMaster;
/** Master data union. */
union
{
/** Data (master) for delta verification. */
struct
{
/** Verification test TSC values for the master. */
uint64_t volatile auTscs[32];
} Verify;
/** Data (master) for measurement method \#2. */
struct
{
/** Data and sequence number. */
SUPDRVTSCDELTAMETHOD2 Data;
/** The lag setting for the next run. */
bool fLag;
/** Number of hits. */
uint32_t cHits;
} M2;
} uMaster;
/** The verifier verdict, VINF_SUCCESS if ok, VERR_OUT_OF_RANGE if not,
* VERR_TRY_AGAIN on timeout. */
int32_t rcVerify;
#ifdef TSCDELTA_VERIFY_WITH_STATS
/** The maximum difference between TSC read during delta verification. */
int64_t cMaxVerifyTscTicks;
/** The minimum difference between two TSC reads during verification. */
int64_t cMinVerifyTscTicks;
/** The bad TSC diff, worker relative to master (= worker - master).
* Negative value means the worker is behind the master. */
int64_t iVerifyBadTscDiff;
#endif
/** @} */
/** Padding to make sure the uVar1 is in its own cache line. */
uint64_t au64CacheLinePaddingBetween[GIP_TSC_DELTA_CACHE_LINE_SIZE / sizeof(uint64_t)];
/** @name Proletarian
* @{ */
/** Pointer to the worker's synchronization struct (on stack). */
PSUPTSCDELTASYNC2 volatile pSyncWorker;
/** The time the worker spent in the MP worker. */
uint64_t cElapsedWorkerTscTicks;
/** Worker data union. */
union
{
/** Data (worker) for delta verification. */
struct
{
/** Verification test TSC values for the worker. */
uint64_t volatile auTscs[32];
} Verify;
/** Data (worker) for measurement method \#2. */
struct
{
/** Data and sequence number. */
SUPDRVTSCDELTAMETHOD2 Data;
/** The lag setting for the next run (set by master). */
bool fLag;
} M2;
} uWorker;
/** @} */
/** Padding to make sure the above is in its own cache line. */
uint64_t au64CacheLinePaddingAfter[GIP_TSC_DELTA_CACHE_LINE_SIZE / sizeof(uint64_t)];
} SUPDRVGIPTSCDELTARGS;
typedef SUPDRVGIPTSCDELTARGS *PSUPDRVGIPTSCDELTARGS;
/** @name Macros that implements the basic synchronization steps common to
* the algorithms.
*
* Must be used from loop as the timeouts are implemented via 'break' statements
* at the moment.
*
* @{
*/
#if defined(DEBUG_bird) /* || defined(VBOX_STRICT) */
# define TSCDELTA_DBG_VARS() uint32_t iDbgCounter
# define TSCDELTA_DBG_START_LOOP() do { iDbgCounter = 0; } while (0)
# define TSCDELTA_DBG_CHECK_LOOP() \
do { iDbgCounter++; if ((iDbgCounter & UINT32_C(0x01ffffff)) == 0) RT_BREAKPOINT(); } while (0)
#else
# define TSCDELTA_DBG_VARS() ((void)0)
# define TSCDELTA_DBG_START_LOOP() ((void)0)
# define TSCDELTA_DBG_CHECK_LOOP() ((void)0)
#endif
#if 0
# define TSCDELTA_DBG_SYNC_MSG(a_Args) SUPR0Printf a_Args
#else
# define TSCDELTA_DBG_SYNC_MSG(a_Args) ((void)0)
#endif
#if 0
# define TSCDELTA_DBG_SYNC_MSG2(a_Args) SUPR0Printf a_Args
#else
# define TSCDELTA_DBG_SYNC_MSG2(a_Args) ((void)0)
#endif
#if 0
# define TSCDELTA_DBG_SYNC_MSG9(a_Args) SUPR0Printf a_Args
#else
# define TSCDELTA_DBG_SYNC_MSG9(a_Args) ((void)0)
#endif
static bool supdrvTscDeltaSync2_Before(PSUPTSCDELTASYNC2 pMySync, PSUPTSCDELTASYNC2 pOtherSync,
bool fIsMaster, PRTCCUINTREG pfEFlags, PSUPDRVGIPTSCDELTARGS pArgs)
{
uint32_t iMySeq = fIsMaster ? 0 : 256;
uint32_t const iMaxSeq = iMySeq + 16; /* For the last loop, darn linux/freebsd C-ishness. */
uint32_t u32Tmp;
uint32_t iSync2Loops = 0;
RTCCUINTREG fEFlags;
TSCDELTA_DBG_VARS();
*pfEFlags = X86_EFL_IF | X86_EFL_1; /* should shut up most nagging compilers. */
/*
* The master tells the worker to get on it's mark.
*/
if (fIsMaster)
{
if (RT_LIKELY(ASMAtomicCmpXchgU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_STEADY, GIP_TSC_DELTA_SYNC2_READY)))
{ /* likely*/ }
else
{
TSCDELTA_DBG_SYNC_MSG(("sync/before/%s: #1 uSyncVar=%#x\n", fIsMaster ? "master" : "worker", pOtherSync->uSyncVar));
return false;
}
}
/*
* Wait for the on your mark signal (ack in the master case). We process timeouts here.
*/
ASMAtomicWriteU32(&(pMySync)->uSyncSeq, 0);
for (;;)
{
fEFlags = ASMIntDisableFlags();
u32Tmp = ASMAtomicReadU32(&pMySync->uSyncVar);
if (u32Tmp == GIP_TSC_DELTA_SYNC2_STEADY)
break;
ASMSetFlags(fEFlags);
ASMNopPause();
/* Abort? */
if (u32Tmp != GIP_TSC_DELTA_SYNC2_READY)
{
TSCDELTA_DBG_SYNC_MSG(("sync/before/%s: #2 u32Tmp=%#x\n", fIsMaster ? "master" : "worker", u32Tmp));
return false;
}
/* Check for timeouts every so often (not every loop in case RDTSC is
trapping or something). Must check the first time around. */
#if 0 /* For debugging the timeout paths. */
static uint32_t volatile xxx;
#endif
if ( ( (iSync2Loops & 0x3ff) == 0
&& ASMReadTSC() - pMySync->uTscStart > pMySync->cMaxTscTicks)
#if 0 /* This is crazy, I know, but enable this code and the results are markedly better when enabled on the 1.4GHz AMD (debug). */
|| (!fIsMaster && (++xxx & 0xf) == 0)
#endif
)
{
/* Try switch our own state into timeout mode so the master cannot tell us to 'GO',
ignore the timeout if we've got the go ahead already (simpler). */
if (ASMAtomicCmpXchgU32(&pMySync->uSyncVar, GIP_TSC_DELTA_SYNC2_TIMEOUT, GIP_TSC_DELTA_SYNC2_READY))
{
TSCDELTA_DBG_SYNC_MSG(("sync/before/%s: timeout\n", fIsMaster ? "master" : "worker"));
ASMAtomicCmpXchgU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_TIMEOUT, GIP_TSC_DELTA_SYNC2_STEADY);
ASMAtomicWriteBool(&pArgs->fTimedOut, true);
return false;
}
}
iSync2Loops++;
}
/*
* Interrupts are now disabled and will remain disabled until we do
* TSCDELTA_MASTER_SYNC_AFTER / TSCDELTA_OTHER_SYNC_AFTER.
*/
*pfEFlags = fEFlags;
/*
* The worker tells the master that it is on its mark and that the master
* need to get into position as well.
*/
if (!fIsMaster)
{
if (RT_LIKELY(ASMAtomicCmpXchgU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_STEADY, GIP_TSC_DELTA_SYNC2_READY)))
{ /* likely */ }
else
{
ASMSetFlags(fEFlags);
TSCDELTA_DBG_SYNC_MSG(("sync/before/%s: #3 uSyncVar=%#x\n", fIsMaster ? "master" : "worker", pOtherSync->uSyncVar));
return false;
}
}
/*
* The master sends the 'go' to the worker and wait for ACK.
*/
if (fIsMaster)
{
if (RT_LIKELY(ASMAtomicCmpXchgU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_GO, GIP_TSC_DELTA_SYNC2_STEADY)))
{ /* likely */ }
else
{
ASMSetFlags(fEFlags);
TSCDELTA_DBG_SYNC_MSG(("sync/before/%s: #4 uSyncVar=%#x\n", fIsMaster ? "master" : "worker", pOtherSync->uSyncVar));
return false;
}
}
/*
* Wait for the 'go' signal (ack in the master case).
*/
TSCDELTA_DBG_START_LOOP();
for (;;)
{
u32Tmp = ASMAtomicReadU32(&pMySync->uSyncVar);
if (u32Tmp == GIP_TSC_DELTA_SYNC2_GO)
break;
if (RT_LIKELY(u32Tmp == GIP_TSC_DELTA_SYNC2_STEADY))
{ /* likely */ }
else
{
ASMSetFlags(fEFlags);
TSCDELTA_DBG_SYNC_MSG(("sync/before/%s: #5 u32Tmp=%#x\n", fIsMaster ? "master" : "worker", u32Tmp));
return false;
}
TSCDELTA_DBG_CHECK_LOOP();
ASMNopPause();
}
/*
* The worker acks the 'go' (shouldn't fail).
*/
if (!fIsMaster)
{
if (RT_LIKELY(ASMAtomicCmpXchgU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_GO, GIP_TSC_DELTA_SYNC2_STEADY)))
{ /* likely */ }
else
{
ASMSetFlags(fEFlags);
TSCDELTA_DBG_SYNC_MSG(("sync/before/%s: #6 uSyncVar=%#x\n", fIsMaster ? "master" : "worker", pOtherSync->uSyncVar));
return false;
}
}
/*
* Try enter mostly lockstep execution with it.
*/
for (;;)
{
uint32_t iOtherSeq1, iOtherSeq2;
ASMCompilerBarrier();
ASMSerializeInstruction();
ASMAtomicWriteU32(&pMySync->uSyncSeq, iMySeq);
ASMNopPause();
iOtherSeq1 = ASMAtomicXchgU32(&pOtherSync->uSyncSeq, iMySeq);
ASMNopPause();
iOtherSeq2 = ASMAtomicReadU32(&pMySync->uSyncSeq);
ASMCompilerBarrier();
if (iOtherSeq1 == iOtherSeq2)
return true;
/* Did the other guy give up? Should we give up? */
if ( iOtherSeq1 == UINT32_MAX
|| iOtherSeq2 == UINT32_MAX)
return true;
if (++iMySeq >= iMaxSeq)
{
ASMAtomicWriteU32(&pMySync->uSyncSeq, UINT32_MAX);
return true;
}
ASMNopPause();
}
}
#define TSCDELTA_MASTER_SYNC_BEFORE(a_pMySync, a_pOtherSync, a_pfEFlags, a_pArgs) \
if (RT_LIKELY(supdrvTscDeltaSync2_Before(a_pMySync, a_pOtherSync, true /*fIsMaster*/, a_pfEFlags, a_pArgs))) \
{ /*likely*/ } \
else if (true) \
{ \
TSCDELTA_DBG_SYNC_MSG9(("sync/before/master: #89\n")); \
break; \
} else do {} while (0)
#define TSCDELTA_OTHER_SYNC_BEFORE(a_pMySync, a_pOtherSync, a_pfEFlags, a_pArgs) \
if (RT_LIKELY(supdrvTscDeltaSync2_Before(a_pMySync, a_pOtherSync, false /*fIsMaster*/, a_pfEFlags, a_pArgs))) \
{ /*likely*/ } \
else if (true) \
{ \
TSCDELTA_DBG_SYNC_MSG9(("sync/before/other: #89\n")); \
break; \
} else do {} while (0)
static bool supdrvTscDeltaSync2_After(PSUPTSCDELTASYNC2 pMySync, PSUPTSCDELTASYNC2 pOtherSync,
bool fIsMaster, RTCCUINTREG fEFlags)
{
TSCDELTA_DBG_VARS();
/*
* Wait for the 'ready' signal. In the master's case, this means the
* worker has completed its data collection, while in the worker's case it
* means the master is done processing the data and it's time for the next
* loop iteration (or whatever).
*/
ASMSetFlags(fEFlags);
TSCDELTA_DBG_START_LOOP();
for (;;)
{
uint32_t u32Tmp = ASMAtomicReadU32(&pMySync->uSyncVar);
if ( u32Tmp == GIP_TSC_DELTA_SYNC2_READY
|| (u32Tmp == GIP_TSC_DELTA_SYNC2_STEADY && !fIsMaster) /* kicked twice => race */ )
return true;
ASMNopPause();
if (RT_LIKELY(u32Tmp == GIP_TSC_DELTA_SYNC2_GO))
{ /* likely */}
else
{
TSCDELTA_DBG_SYNC_MSG(("sync/after/other: #1 u32Tmp=%#x\n", u32Tmp));
return false; /* shouldn't ever happen! */
}
TSCDELTA_DBG_CHECK_LOOP();
ASMNopPause();
}
}
#define TSCDELTA_MASTER_SYNC_AFTER(a_pMySync, a_pOtherSync, a_fEFlags) \
if (RT_LIKELY(supdrvTscDeltaSync2_After(a_pMySync, a_pOtherSync, true /*fIsMaster*/, a_fEFlags))) \
{ /* likely */ } \
else if (true) \
{ \
TSCDELTA_DBG_SYNC_MSG9(("sync/after/master: #97\n")); \
break; \
} else do {} while (0)
#define TSCDELTA_MASTER_KICK_OTHER_OUT_OF_AFTER(a_pMySync, a_pOtherSync) \
/* \
* Tell the worker that we're done processing the data and ready for the next round. \
*/ \
if (RT_LIKELY(ASMAtomicCmpXchgU32(&(a_pOtherSync)->uSyncVar, GIP_TSC_DELTA_SYNC2_READY, GIP_TSC_DELTA_SYNC2_GO))) \
{ /* likely */ } \
else if (true)\
{ \
TSCDELTA_DBG_SYNC_MSG(("sync/after/master: #99 uSyncVar=%#x\n", (a_pOtherSync)->uSyncVar)); \
break; \
} else do {} while (0)
#define TSCDELTA_OTHER_SYNC_AFTER(a_pMySync, a_pOtherSync, a_fEFlags) \
if (true) { \
/* \
* Tell the master that we're done collecting data and wait for the next round to start. \
*/ \
if (RT_LIKELY(ASMAtomicCmpXchgU32(&(a_pOtherSync)->uSyncVar, GIP_TSC_DELTA_SYNC2_READY, GIP_TSC_DELTA_SYNC2_GO))) \
{ /* likely */ } \
else \
{ \
ASMSetFlags(a_fEFlags); \
TSCDELTA_DBG_SYNC_MSG(("sync/after/other: #0 uSyncVar=%#x\n", (a_pOtherSync)->uSyncVar)); \
break; \
} \
if (RT_LIKELY(supdrvTscDeltaSync2_After(a_pMySync, a_pOtherSync, false /*fIsMaster*/, a_fEFlags))) \
{ /* likely */ } \
else \
{ \
TSCDELTA_DBG_SYNC_MSG9(("sync/after/other: #98\n")); \
break; \
} \
} else do {} while (0)
/** @} */
#ifdef GIP_TSC_DELTA_METHOD_1
/**
* TSC delta measurment algorithm \#1 (GIP_TSC_DELTA_METHOD_1).
*
*
* We ignore the first few runs of the loop in order to prime the
* cache. Also, we need to be careful about using 'pause' instruction
* in critical busy-wait loops in this code - it can cause undesired
* behaviour with hyperthreading.
*
* We try to minimize the measurement error by computing the minimum
* read time of the compare statement in the worker by taking TSC
* measurements across it.
*
* It must be noted that the computed minimum read time is mostly to
* eliminate huge deltas when the worker is too early and doesn't by
* itself help produce more accurate deltas. We allow two times the
* computed minimum as an arbibtrary acceptable threshold. Therefore,
* it is still possible to get negative deltas where there are none
* when the worker is earlier. As long as these occasional negative
* deltas are lower than the time it takes to exit guest-context and
* the OS to reschedule EMT on a different CPU we won't expose a TSC
* that jumped backwards. It is because of the existence of the
* negative deltas we don't recompute the delta with the master and
* worker interchanged to eliminate the remaining measurement error.
*
*
* @param pArgs The argument/state data.
* @param pMySync My synchronization structure.
* @param pOtherSync My partner's synchronization structure.
* @param fIsMaster Set if master, clear if worker.
* @param iTry The attempt number.
*/
static void supdrvTscDeltaMethod1Loop(PSUPDRVGIPTSCDELTARGS pArgs, PSUPTSCDELTASYNC2 pMySync, PSUPTSCDELTASYNC2 pOtherSync,
bool fIsMaster, uint32_t iTry)
{
PSUPGIPCPU pGipCpuWorker = pArgs->pWorker;
PSUPGIPCPU pGipCpuMaster = pArgs->pMaster;
uint64_t uMinCmpReadTime = UINT64_MAX;
unsigned iLoop;
NOREF(iTry);
for (iLoop = 0; iLoop < GIP_TSC_DELTA_LOOPS; iLoop++)
{
RTCCUINTREG fEFlags;
if (fIsMaster)
{
/*
* The master.
*/
AssertMsg(pGipCpuMaster->u64TSCSample == GIP_TSC_DELTA_RSVD,
("%#llx idMaster=%#x idWorker=%#x (idGipMaster=%#x)\n",
pGipCpuMaster->u64TSCSample, pGipCpuMaster->idCpu, pGipCpuWorker->idCpu, pArgs->pDevExt->idGipMaster));
TSCDELTA_MASTER_SYNC_BEFORE(pMySync, pOtherSync, &fEFlags, pArgs);
do
{
ASMSerializeInstruction();
ASMAtomicWriteU64(&pGipCpuMaster->u64TSCSample, ASMReadTSC());
} while (pGipCpuMaster->u64TSCSample == GIP_TSC_DELTA_RSVD);
TSCDELTA_MASTER_SYNC_AFTER(pMySync, pOtherSync, fEFlags);
/* Process the data. */
if (iLoop > GIP_TSC_DELTA_PRIMER_LOOPS + GIP_TSC_DELTA_READ_TIME_LOOPS)
{
if (pGipCpuWorker->u64TSCSample != GIP_TSC_DELTA_RSVD)
{
int64_t iDelta = pGipCpuWorker->u64TSCSample
- (pGipCpuMaster->u64TSCSample - pGipCpuMaster->i64TSCDelta);
if ( iDelta >= GIP_TSC_DELTA_INITIAL_MASTER_VALUE
? iDelta < pGipCpuWorker->i64TSCDelta
: iDelta > pGipCpuWorker->i64TSCDelta || pGipCpuWorker->i64TSCDelta == INT64_MAX)
pGipCpuWorker->i64TSCDelta = iDelta;
}
}
/* Reset our TSC sample and tell the worker to move on. */
ASMAtomicWriteU64(&pGipCpuMaster->u64TSCSample, GIP_TSC_DELTA_RSVD);
TSCDELTA_MASTER_KICK_OTHER_OUT_OF_AFTER(pMySync, pOtherSync);
}
else
{
/*
* The worker.
*/
uint64_t uTscWorker;
uint64_t uTscWorkerFlushed;
uint64_t uCmpReadTime;
ASMAtomicReadU64(&pGipCpuMaster->u64TSCSample); /* Warm the cache line. */
TSCDELTA_OTHER_SYNC_BEFORE(pMySync, pOtherSync, &fEFlags, pArgs);
/*
* Keep reading the TSC until we notice that the master has read his. Reading
* the TSC -after- the master has updated the memory is way too late. We thus
* compensate by trying to measure how long it took for the worker to notice
* the memory flushed from the master.
*/
do
{
ASMSerializeInstruction();
uTscWorker = ASMReadTSC();
} while (pGipCpuMaster->u64TSCSample == GIP_TSC_DELTA_RSVD);
ASMSerializeInstruction();
uTscWorkerFlushed = ASMReadTSC();
uCmpReadTime = uTscWorkerFlushed - uTscWorker;
if (iLoop > GIP_TSC_DELTA_PRIMER_LOOPS + GIP_TSC_DELTA_READ_TIME_LOOPS)
{
/* This is totally arbitrary a.k.a I don't like it but I have no better ideas for now. */
if (uCmpReadTime < (uMinCmpReadTime << 1))
{
ASMAtomicWriteU64(&pGipCpuWorker->u64TSCSample, uTscWorker);
if (uCmpReadTime < uMinCmpReadTime)
uMinCmpReadTime = uCmpReadTime;
}
else
ASMAtomicWriteU64(&pGipCpuWorker->u64TSCSample, GIP_TSC_DELTA_RSVD);
}
else if (iLoop > GIP_TSC_DELTA_PRIMER_LOOPS)
{
if (uCmpReadTime < uMinCmpReadTime)
uMinCmpReadTime = uCmpReadTime;
}
TSCDELTA_OTHER_SYNC_AFTER(pMySync, pOtherSync, fEFlags);
}
}
TSCDELTA_DBG_SYNC_MSG9(("sync/method1loop/%s: #92 iLoop=%u MyState=%#x\n", fIsMaster ? "master" : "worker", iLoop,
pMySync->uSyncVar));
/*
* We must reset the worker TSC sample value in case it gets picked as a
* GIP master later on (it's trashed above, naturally).
*/
if (!fIsMaster)
ASMAtomicWriteU64(&pGipCpuWorker->u64TSCSample, GIP_TSC_DELTA_RSVD);
}
#endif /* GIP_TSC_DELTA_METHOD_1 */
#ifdef GIP_TSC_DELTA_METHOD_2
/*
* TSC delta measurement algorithm \#2 configuration and code - Experimental!!
*/
# define GIP_TSC_DELTA_M2_LOOPS (7 + GIP_TSC_DELTA_M2_PRIMER_LOOPS)
# define GIP_TSC_DELTA_M2_PRIMER_LOOPS 0
static void supdrvTscDeltaMethod2ProcessDataOnMaster(PSUPDRVGIPTSCDELTARGS pArgs, uint32_t iLoop)
{
int64_t iMasterTscDelta = pArgs->pMaster->i64TSCDelta;
int64_t iBestDelta = pArgs->pWorker->i64TSCDelta;
uint32_t idxResult;
uint32_t cHits = 0;
/*
* Look for matching entries in the master and worker tables.
*/
for (idxResult = 0; idxResult < RT_ELEMENTS(pArgs->uMaster.M2.Data.aResults); idxResult++)
{
uint32_t idxOther = pArgs->uMaster.M2.Data.aResults[idxResult].iSeqOther;
if (idxOther & 1)
{
idxOther >>= 1;
if (idxOther < RT_ELEMENTS(pArgs->uWorker.M2.Data.aResults))
{
if (pArgs->uWorker.M2.Data.aResults[idxOther].iSeqOther == pArgs->uMaster.M2.Data.aResults[idxResult].iSeqMine)
{
int64_t iDelta;
iDelta = pArgs->uWorker.M2.Data.aResults[idxOther].uTsc
- (pArgs->uMaster.M2.Data.aResults[idxResult].uTsc - iMasterTscDelta);
if ( iDelta >= GIP_TSC_DELTA_INITIAL_MASTER_VALUE
? iDelta < iBestDelta
: iDelta > iBestDelta || iBestDelta == INT64_MAX)
iBestDelta = iDelta;
cHits++;
}
}
}
}
/*
* Save the results.
*/
if (cHits > 2)
pArgs->pWorker->i64TSCDelta = iBestDelta;
pArgs->uMaster.M2.cHits += cHits;
}
/**
* The core function of the 2nd TSC delta mesurment algorithm.
*
* The idea here is that we have the two CPUs execute the exact same code
* collecting a largish set of TSC samples. The code has one data dependency on
* the other CPU which intention it is to synchronize the execution as well as
* help cross references the two sets of TSC samples (the sequence numbers).
*
* The @a fLag parameter is used to modify the execution a tiny bit on one or
* both of the CPUs. When @a fLag differs between the CPUs, it is thought that
* it will help with making the CPUs enter lock step execution occationally.
*
*/
static void supdrvTscDeltaMethod2CollectData(PSUPDRVTSCDELTAMETHOD2 pMyData, uint32_t volatile *piOtherSeqNo, bool fLag)
{
SUPDRVTSCDELTAMETHOD2ENTRY *pEntry = &pMyData->aResults[0];
uint32_t cLeft = RT_ELEMENTS(pMyData->aResults);
ASMAtomicWriteU32(&pMyData->iCurSeqNo, 0);
ASMSerializeInstruction();
while (cLeft-- > 0)
{
uint64_t uTsc;
uint32_t iSeqMine = ASMAtomicIncU32(&pMyData->iCurSeqNo);
uint32_t iSeqOther = ASMAtomicReadU32(piOtherSeqNo);
ASMCompilerBarrier();
ASMSerializeInstruction(); /* Way better result than with ASMMemoryFenceSSE2() in this position! */
uTsc = ASMReadTSC();
ASMAtomicIncU32(&pMyData->iCurSeqNo);
ASMCompilerBarrier();
ASMSerializeInstruction();
pEntry->iSeqMine = iSeqMine;
pEntry->iSeqOther = iSeqOther;
pEntry->uTsc = uTsc;
pEntry++;
ASMSerializeInstruction();
if (fLag)
ASMNopPause();
}
}
/**
* TSC delta measurment algorithm \#2 (GIP_TSC_DELTA_METHOD_2).
*
* See supdrvTscDeltaMethod2CollectData for algorithm details.
*
* @param pArgs The argument/state data.
* @param pMySync My synchronization structure.
* @param pOtherSync My partner's synchronization structure.
* @param fIsMaster Set if master, clear if worker.
* @param iTry The attempt number.
*/
static void supdrvTscDeltaMethod2Loop(PSUPDRVGIPTSCDELTARGS pArgs, PSUPTSCDELTASYNC2 pMySync, PSUPTSCDELTASYNC2 pOtherSync,
bool fIsMaster, uint32_t iTry)
{
unsigned iLoop;
for (iLoop = 0; iLoop < GIP_TSC_DELTA_M2_LOOPS; iLoop++)
{
RTCCUINTREG fEFlags;
if (fIsMaster)
{
/*
* Adjust the loop lag fudge.
*/
# if GIP_TSC_DELTA_M2_PRIMER_LOOPS > 0
if (iLoop < GIP_TSC_DELTA_M2_PRIMER_LOOPS)
{
/* Lag during the priming to be nice to everyone.. */
pArgs->uMaster.M2.fLag = true;
pArgs->uWorker.M2.fLag = true;
}
else
# endif
if (iLoop < (GIP_TSC_DELTA_M2_LOOPS - GIP_TSC_DELTA_M2_PRIMER_LOOPS) / 4)
{
/* 25 % of the body without lagging. */
pArgs->uMaster.M2.fLag = false;
pArgs->uWorker.M2.fLag = false;
}
else if (iLoop < (GIP_TSC_DELTA_M2_LOOPS - GIP_TSC_DELTA_M2_PRIMER_LOOPS) / 4 * 2)
{
/* 25 % of the body with both lagging. */
pArgs->uMaster.M2.fLag = true;
pArgs->uWorker.M2.fLag = true;
}
else
{
/* 50% of the body with alternating lag. */
pArgs->uMaster.M2.fLag = (iLoop & 1) == 0;
pArgs->uWorker.M2.fLag= (iLoop & 1) == 1;
}
/*
* Sync up with the worker and collect data.
*/
TSCDELTA_MASTER_SYNC_BEFORE(pMySync, pOtherSync, &fEFlags, pArgs);
supdrvTscDeltaMethod2CollectData(&pArgs->uMaster.M2.Data, &pArgs->uWorker.M2.Data.iCurSeqNo, pArgs->uMaster.M2.fLag);
TSCDELTA_MASTER_SYNC_AFTER(pMySync, pOtherSync, fEFlags);
/*
* Process the data.
*/
# if GIP_TSC_DELTA_M2_PRIMER_LOOPS > 0
if (iLoop >= GIP_TSC_DELTA_M2_PRIMER_LOOPS)
# endif
supdrvTscDeltaMethod2ProcessDataOnMaster(pArgs, iLoop);
TSCDELTA_MASTER_KICK_OTHER_OUT_OF_AFTER(pMySync, pOtherSync);
}
else
{
/*
* The worker.
*/
TSCDELTA_OTHER_SYNC_BEFORE(pMySync, pOtherSync, &fEFlags, pArgs);
supdrvTscDeltaMethod2CollectData(&pArgs->uWorker.M2.Data, &pArgs->uMaster.M2.Data.iCurSeqNo, pArgs->uWorker.M2.fLag);
TSCDELTA_OTHER_SYNC_AFTER(pMySync, pOtherSync, fEFlags);
}
}
}
#endif /* GIP_TSC_DELTA_METHOD_2 */
static int supdrvTscDeltaVerify(PSUPDRVGIPTSCDELTARGS pArgs, PSUPTSCDELTASYNC2 pMySync,
PSUPTSCDELTASYNC2 pOtherSync, bool fIsMaster, int64_t iWorkerTscDelta)
{
/*PSUPGIPCPU pGipCpuWorker = pArgs->pWorker; - unused */
PSUPGIPCPU pGipCpuMaster = pArgs->pMaster;
uint32_t i;
TSCDELTA_DBG_VARS();
for (;;)
{
RTCCUINTREG fEFlags;
AssertCompile((RT_ELEMENTS(pArgs->uMaster.Verify.auTscs) & 1) == 0);
AssertCompile(RT_ELEMENTS(pArgs->uMaster.Verify.auTscs) == RT_ELEMENTS(pArgs->uWorker.Verify.auTscs));
if (fIsMaster)
{
uint64_t uTscWorker;
TSCDELTA_MASTER_SYNC_BEFORE(pMySync, pOtherSync, &fEFlags, pArgs);
/*
* Collect TSC, master goes first.
*/
for (i = 0; i < RT_ELEMENTS(pArgs->uMaster.Verify.auTscs); i += 2)
{
/* Read, kick & wait #1. */
uint64_t register uTsc = ASMReadTSC();
ASMAtomicWriteU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_GO_GO);
ASMSerializeInstruction();
pArgs->uMaster.Verify.auTscs[i] = uTsc;
TSCDELTA_DBG_START_LOOP();
while (ASMAtomicReadU32(&pMySync->uSyncVar) == GIP_TSC_DELTA_SYNC2_GO)
{
TSCDELTA_DBG_CHECK_LOOP();
ASMNopPause();
}
/* Read, kick & wait #2. */
uTsc = ASMReadTSC();
ASMAtomicWriteU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_GO);
ASMSerializeInstruction();
pArgs->uMaster.Verify.auTscs[i + 1] = uTsc;
TSCDELTA_DBG_START_LOOP();
while (ASMAtomicReadU32(&pMySync->uSyncVar) == GIP_TSC_DELTA_SYNC2_GO_GO)
{
TSCDELTA_DBG_CHECK_LOOP();
ASMNopPause();
}
}
TSCDELTA_MASTER_SYNC_AFTER(pMySync, pOtherSync, fEFlags);
/*
* Process the data.
*/
#ifdef TSCDELTA_VERIFY_WITH_STATS
pArgs->cMaxVerifyTscTicks = INT64_MIN;
pArgs->cMinVerifyTscTicks = INT64_MAX;
pArgs->iVerifyBadTscDiff = 0;
#endif
ASMAtomicWriteS32(&pArgs->rcVerify, VINF_SUCCESS);
uTscWorker = 0;
for (i = 0; i < RT_ELEMENTS(pArgs->uMaster.Verify.auTscs); i++)
{
/* Master vs previous worker entry. */
uint64_t uTscMaster = pArgs->uMaster.Verify.auTscs[i] - pGipCpuMaster->i64TSCDelta;
int64_t iDiff;
if (i > 0)
{
iDiff = uTscMaster - uTscWorker;
#ifdef TSCDELTA_VERIFY_WITH_STATS
if (iDiff > pArgs->cMaxVerifyTscTicks)
pArgs->cMaxVerifyTscTicks = iDiff;
if (iDiff < pArgs->cMinVerifyTscTicks)
pArgs->cMinVerifyTscTicks = iDiff;
#endif
if (iDiff < 0)
{
#ifdef TSCDELTA_VERIFY_WITH_STATS
pArgs->iVerifyBadTscDiff = -iDiff;
#endif
ASMAtomicWriteS32(&pArgs->rcVerify, VERR_OUT_OF_RANGE);
break;
}
}
/* Worker vs master. */
uTscWorker = pArgs->uWorker.Verify.auTscs[i] - iWorkerTscDelta;
iDiff = uTscWorker - uTscMaster;
#ifdef TSCDELTA_VERIFY_WITH_STATS
if (iDiff > pArgs->cMaxVerifyTscTicks)
pArgs->cMaxVerifyTscTicks = iDiff;
if (iDiff < pArgs->cMinVerifyTscTicks)
pArgs->cMinVerifyTscTicks = iDiff;
#endif
if (iDiff < 0)
{
#ifdef TSCDELTA_VERIFY_WITH_STATS
pArgs->iVerifyBadTscDiff = iDiff;
#endif
ASMAtomicWriteS32(&pArgs->rcVerify, VERR_OUT_OF_RANGE);
break;
}
}
/* Done. */
TSCDELTA_MASTER_KICK_OTHER_OUT_OF_AFTER(pMySync, pOtherSync);
}
else
{
/*
* The worker, master leads.
*/
TSCDELTA_OTHER_SYNC_BEFORE(pMySync, pOtherSync, &fEFlags, pArgs);
for (i = 0; i < RT_ELEMENTS(pArgs->uWorker.Verify.auTscs); i += 2)
{
uint64_t register uTsc;
/* Wait, Read and Kick #1. */
TSCDELTA_DBG_START_LOOP();
while (ASMAtomicReadU32(&pMySync->uSyncVar) == GIP_TSC_DELTA_SYNC2_GO)
{
TSCDELTA_DBG_CHECK_LOOP();
ASMNopPause();
}
uTsc = ASMReadTSC();
ASMAtomicWriteU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_GO_GO);
ASMSerializeInstruction();
pArgs->uWorker.Verify.auTscs[i] = uTsc;
/* Wait, Read and Kick #2. */
TSCDELTA_DBG_START_LOOP();
while (ASMAtomicReadU32(&pMySync->uSyncVar) == GIP_TSC_DELTA_SYNC2_GO_GO)
{
TSCDELTA_DBG_CHECK_LOOP();
ASMNopPause();
}
uTsc = ASMReadTSC();
ASMAtomicWriteU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_GO);
ASMSerializeInstruction();
pArgs->uWorker.Verify.auTscs[i + 1] = uTsc;
}
TSCDELTA_OTHER_SYNC_AFTER(pMySync, pOtherSync, fEFlags);
}
return pArgs->rcVerify;
}
/*
* Timed out, please retry.
*/
ASMAtomicWriteS32(&pArgs->rcVerify, VERR_TRY_AGAIN);
return VERR_TIMEOUT;
}
/**
* Handles the special abort procedure during synchronization setup in
* supdrvMeasureTscDeltaCallbackUnwrapped().
*
* @returns 0 (dummy, ignored)
* @param pArgs Pointer to argument/state data.
* @param pMySync Pointer to my sync structure.
* @param fIsMaster Set if we're the master, clear if worker.
* @param fTimeout Set if it's a timeout.
*/
DECL_NO_INLINE(static, int)
supdrvMeasureTscDeltaCallbackAbortSyncSetup(PSUPDRVGIPTSCDELTARGS pArgs, PSUPTSCDELTASYNC2 pMySync, bool fIsMaster, bool fTimeout)
{
PSUPTSCDELTASYNC2 volatile *ppMySync = fIsMaster ? &pArgs->pSyncMaster : &pArgs->pSyncWorker;
PSUPTSCDELTASYNC2 volatile *ppOtherSync = fIsMaster ? &pArgs->pSyncWorker : &pArgs->pSyncMaster;
TSCDELTA_DBG_VARS();
/*
* Clear our sync pointer and make sure the abort flag is set.
*/
ASMAtomicWriteNullPtr(ppMySync);
ASMAtomicWriteBool(&pArgs->fAbortSetup, true);
if (fTimeout)
ASMAtomicWriteBool(&pArgs->fTimedOut, true);
/*
* Make sure the other party is out of there and won't be touching our
* sync state again (would cause stack corruption).
*/
TSCDELTA_DBG_START_LOOP();
while (ASMAtomicReadPtrT(ppOtherSync, PSUPTSCDELTASYNC2) != NULL)
{
ASMNopPause();
ASMNopPause();
ASMNopPause();
TSCDELTA_DBG_CHECK_LOOP();
}
return 0;
}
/**
* This is used by supdrvMeasureInitialTscDeltas() to read the TSC on two CPUs
* and compute the delta between them.
*
* To reduce code size a good when timeout handling was added, a dummy return
* value had to be added (saves 1-3 lines per timeout case), thus this
* 'Unwrapped' function and the dummy 0 return value.
*
* @returns 0 (dummy, ignored)
* @param idCpu The CPU we are current scheduled on.
* @param pArgs Pointer to a parameter package.
*
* @remarks Measuring TSC deltas between the CPUs is tricky because we need to
* read the TSC at exactly the same time on both the master and the
* worker CPUs. Due to DMA, bus arbitration, cache locality,
* contention, SMI, pipelining etc. there is no guaranteed way of
* doing this on x86 CPUs.
*/
static int supdrvMeasureTscDeltaCallbackUnwrapped(RTCPUID idCpu, PSUPDRVGIPTSCDELTARGS pArgs)
{
PSUPDRVDEVEXT pDevExt = pArgs->pDevExt;
PSUPGIPCPU pGipCpuWorker = pArgs->pWorker;
PSUPGIPCPU pGipCpuMaster = pArgs->pMaster;
bool const fIsMaster = idCpu == pGipCpuMaster->idCpu;
uint32_t iTry;
PSUPTSCDELTASYNC2 volatile *ppMySync = fIsMaster ? &pArgs->pSyncMaster : &pArgs->pSyncWorker;
PSUPTSCDELTASYNC2 volatile *ppOtherSync = fIsMaster ? &pArgs->pSyncWorker : &pArgs->pSyncMaster;
SUPTSCDELTASYNC2 MySync;
PSUPTSCDELTASYNC2 pOtherSync;
int rc;
TSCDELTA_DBG_VARS();
/* A bit of paranoia first. */
if (!pGipCpuMaster || !pGipCpuWorker)
return 0;
/*
* If the CPU isn't part of the measurement, return immediately.
*/
if ( !fIsMaster
&& idCpu != pGipCpuWorker->idCpu)
return 0;
/*
* Set up my synchronization stuff and wait for the other party to show up.
*
* We don't wait forever since the other party may be off fishing (offline,
* spinning with ints disables, whatever), we must play nice to the rest of
* the system as this context generally isn't one in which we will get
* preempted and we may hold up a number of lower priority interrupts.
*/
ASMAtomicWriteU32(&MySync.uSyncVar, GIP_TSC_DELTA_SYNC2_PRESTART_WAIT);
ASMAtomicWritePtr(ppMySync, &MySync);
MySync.uTscStart = ASMReadTSC();
MySync.cMaxTscTicks = pArgs->cMaxTscTicks;
/* Look for the partner, might not be here yet... Special abort considerations. */
iTry = 0;
TSCDELTA_DBG_START_LOOP();
while ((pOtherSync = ASMAtomicReadPtrT(ppOtherSync, PSUPTSCDELTASYNC2)) == NULL)
{
ASMNopPause();
if ( ASMAtomicReadBool(&pArgs->fAbortSetup)
|| !RTMpIsCpuOnline(fIsMaster ? pGipCpuWorker->idCpu : pGipCpuWorker->idCpu) )
return supdrvMeasureTscDeltaCallbackAbortSyncSetup(pArgs, &MySync, fIsMaster, false /*fTimeout*/);
if ( (iTry++ & 0xff) == 0
&& ASMReadTSC() - MySync.uTscStart > pArgs->cMaxTscTicks)
return supdrvMeasureTscDeltaCallbackAbortSyncSetup(pArgs, &MySync, fIsMaster, true /*fTimeout*/);
TSCDELTA_DBG_CHECK_LOOP();
ASMNopPause();
}
/* I found my partner, waiting to be found... Special abort considerations. */
if (fIsMaster)
if (!ASMAtomicCmpXchgU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_READY, GIP_TSC_DELTA_SYNC2_PRESTART_WAIT)) /* parnaoia */
return supdrvMeasureTscDeltaCallbackAbortSyncSetup(pArgs, &MySync, fIsMaster, false /*fTimeout*/);
iTry = 0;
TSCDELTA_DBG_START_LOOP();
while (ASMAtomicReadU32(&MySync.uSyncVar) == GIP_TSC_DELTA_SYNC2_PRESTART_WAIT)
{
ASMNopPause();
if (ASMAtomicReadBool(&pArgs->fAbortSetup))
return supdrvMeasureTscDeltaCallbackAbortSyncSetup(pArgs, &MySync, fIsMaster, false /*fTimeout*/);
if ( (iTry++ & 0xff) == 0
&& ASMReadTSC() - MySync.uTscStart > pArgs->cMaxTscTicks)
{
if ( fIsMaster
&& !ASMAtomicCmpXchgU32(&MySync.uSyncVar, GIP_TSC_DELTA_SYNC2_PRESTART_ABORT, GIP_TSC_DELTA_SYNC2_PRESTART_WAIT))
break; /* race #1: slave has moved on, handle timeout in loop instead. */
return supdrvMeasureTscDeltaCallbackAbortSyncSetup(pArgs, &MySync, fIsMaster, true /*fTimeout*/);
}
TSCDELTA_DBG_CHECK_LOOP();
}
if (!fIsMaster)
if (!ASMAtomicCmpXchgU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_READY, GIP_TSC_DELTA_SYNC2_PRESTART_WAIT)) /* race #1 */
return supdrvMeasureTscDeltaCallbackAbortSyncSetup(pArgs, &MySync, fIsMaster, false /*fTimeout*/);
/** @todo Add a resumable state to pArgs so we don't waste time if we time
* out or something. Timeouts are legit, any of the two CPUs may get
* interrupted. */
/*
* Start by seeing if we have a zero delta between the two CPUs.
* This should normally be the case.
*/
rc = supdrvTscDeltaVerify(pArgs, &MySync, pOtherSync, fIsMaster, GIP_TSC_DELTA_INITIAL_MASTER_VALUE);
if (RT_SUCCESS(rc))
{
if (fIsMaster)
{
ASMAtomicWriteS64(&pGipCpuWorker->i64TSCDelta, GIP_TSC_DELTA_INITIAL_MASTER_VALUE);
RTCpuSetDelByIndex(&pDevExt->TscDeltaCpuSet, pGipCpuWorker->iCpuSet);
RTCpuSetAddByIndex(&pDevExt->TscDeltaObtainedCpuSet, pGipCpuWorker->iCpuSet);
}
}
/*
* If the verification didn't time out, do regular delta measurements.
* We retry this until we get a reasonable value.
*/
else if (rc != VERR_TIMEOUT)
{
Assert(pGipCpuWorker->i64TSCDelta == INT64_MAX);
for (iTry = 0; iTry < 12; iTry++)
{
/*
* Check the state before we start.
*/
uint32_t u32Tmp = ASMAtomicReadU32(&MySync.uSyncVar);
if ( u32Tmp != GIP_TSC_DELTA_SYNC2_READY
&& (fIsMaster || u32Tmp != GIP_TSC_DELTA_SYNC2_STEADY) /* worker may be late prepping for the next round */ )
{
TSCDELTA_DBG_SYNC_MSG(("sync/loop/%s: #0 iTry=%u MyState=%#x\n", fIsMaster ? "master" : "worker", iTry, u32Tmp));
break;
}
/*
* Do the measurements.
*/
#ifdef GIP_TSC_DELTA_METHOD_1
supdrvTscDeltaMethod1Loop(pArgs, &MySync, pOtherSync, fIsMaster, iTry);
#elif defined(GIP_TSC_DELTA_METHOD_2)
supdrvTscDeltaMethod2Loop(pArgs, &MySync, pOtherSync, fIsMaster, iTry);
#else
# error "huh??"
#endif
/*
* Check the state.
*/
u32Tmp = ASMAtomicReadU32(&MySync.uSyncVar);
if ( u32Tmp != GIP_TSC_DELTA_SYNC2_READY
&& (fIsMaster || u32Tmp != GIP_TSC_DELTA_SYNC2_STEADY) /* worker may be late prepping for the next round */ )
{
if (fIsMaster)
TSCDELTA_DBG_SYNC_MSG(("sync/loop/master: #1 iTry=%u MyState=%#x\n", iTry, u32Tmp));
else
TSCDELTA_DBG_SYNC_MSG2(("sync/loop/worker: #1 iTry=%u MyState=%#x\n", iTry, u32Tmp));
break;
}
/*
* Success? If so, stop trying. Master decides.
*/
if (fIsMaster)
{
if (pGipCpuWorker->i64TSCDelta != INT64_MAX)
{
RTCpuSetDelByIndex(&pDevExt->TscDeltaCpuSet, pGipCpuWorker->iCpuSet);
RTCpuSetAddByIndex(&pDevExt->TscDeltaObtainedCpuSet, pGipCpuWorker->iCpuSet);
TSCDELTA_DBG_SYNC_MSG2(("sync/loop/master: #9 iTry=%u MyState=%#x\n", iTry, MySync.uSyncVar));
break;
}
}
}
if (fIsMaster)
pArgs->iTry = iTry;
}
/*
* End the synchroniziation dance. We tell the other that we're done,
* then wait for the same kind of reply.
*/
ASMAtomicWriteU32(&pOtherSync->uSyncVar, GIP_TSC_DELTA_SYNC2_FINAL);
ASMAtomicWriteNullPtr(ppMySync);
iTry = 0;
TSCDELTA_DBG_START_LOOP();
while (ASMAtomicReadU32(&MySync.uSyncVar) != GIP_TSC_DELTA_SYNC2_FINAL)
{
iTry++;
if ( iTry == 0
&& !RTMpIsCpuOnline(fIsMaster ? pGipCpuWorker->idCpu : pGipCpuWorker->idCpu))
break; /* this really shouldn't happen. */
TSCDELTA_DBG_CHECK_LOOP();
ASMNopPause();
}
/*
* Collect some runtime stats.
*/
if (fIsMaster)
pArgs->cElapsedMasterTscTicks = ASMReadTSC() - MySync.uTscStart;
else
pArgs->cElapsedWorkerTscTicks = ASMReadTSC() - MySync.uTscStart;
return 0;
}
/**
* Callback used by supdrvMeasureInitialTscDeltas() to read the TSC on two CPUs
* and compute the delta between them.
*
* @param idCpu The CPU we are current scheduled on.
* @param pvUser1 Pointer to a parameter package (SUPDRVGIPTSCDELTARGS).
* @param pvUser2 Unused.
*/
static DECLCALLBACK(void) supdrvMeasureTscDeltaCallback(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
supdrvMeasureTscDeltaCallbackUnwrapped(idCpu, (PSUPDRVGIPTSCDELTARGS)pvUser1);
}
/**
* Measures the TSC delta between the master GIP CPU and one specified worker
* CPU.
*
* @returns VBox status code.
* @retval VERR_SUPDRV_TSC_DELTA_MEASUREMENT_FAILED on pure measurement
* failure.
* @param pDevExt Pointer to the device instance data.
* @param idxWorker The index of the worker CPU from the GIP's array of
* CPUs.
*
* @remarks This must be called with preemption enabled!
*/
static int supdrvMeasureTscDeltaOne(PSUPDRVDEVEXT pDevExt, uint32_t idxWorker)
{
int rc;
int rc2;
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
RTCPUID idMaster = pDevExt->idGipMaster;
PSUPGIPCPU pGipCpuWorker = &pGip->aCPUs[idxWorker];
PSUPGIPCPU pGipCpuMaster;
uint32_t iGipCpuMaster;
/* Validate input a bit. */
AssertReturn(pGip, VERR_INVALID_PARAMETER);
Assert(pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED);
Assert(RTThreadPreemptIsEnabled(NIL_RTTHREAD));
/*
* Don't attempt measuring the delta for the GIP master.
*/
if (pGipCpuWorker->idCpu == idMaster)
{
if (pGipCpuWorker->i64TSCDelta == INT64_MAX) /* This shouldn't happen, but just in case. */
ASMAtomicWriteS64(&pGipCpuWorker->i64TSCDelta, GIP_TSC_DELTA_INITIAL_MASTER_VALUE);
return VINF_SUCCESS;
}
/*
* One measurement at at time, at least for now. We might be using
* broadcast IPIs so, so be nice to the rest of the system.
*/
#ifdef SUPDRV_USE_MUTEX_FOR_GIP
rc = RTSemMutexRequest(pDevExt->mtxTscDelta, RT_INDEFINITE_WAIT);
#else
rc = RTSemFastMutexRequest(pDevExt->mtxTscDelta);
#endif
if (RT_FAILURE(rc))
return rc;
/*
* If the CPU has hyper-threading and the APIC IDs of the master and worker are adjacent,
* try pick a different master. (This fudge only works with multi core systems.)
* ASSUMES related threads have adjacent APIC IDs. ASSUMES two threads per core.
*
* We skip this on AMDs for now as their HTT is different from intel's and
* it doesn't seem to have any favorable effect on the results.
*
* If the master is offline, we need a new master too, so share the code.
*/
iGipCpuMaster = supdrvGipFindCpuIndexForCpuId(pGip, idMaster);
AssertReturn(iGipCpuMaster < pGip->cCpus, VERR_INVALID_CPU_ID);
pGipCpuMaster = &pGip->aCPUs[iGipCpuMaster];
if ( ( (pGipCpuMaster->idApic & ~1) == (pGipCpuWorker->idApic & ~1)
&& ASMHasCpuId()
&& ASMIsValidStdRange(ASMCpuId_EAX(0))
&& (ASMCpuId_EDX(1) & X86_CPUID_FEATURE_EDX_HTT)
&& !ASMIsAmdCpu()
&& pGip->cOnlineCpus > 2)
|| !RTMpIsCpuOnline(idMaster) )
{
uint32_t i;
for (i = 0; i < pGip->cCpus; i++)
if ( i != iGipCpuMaster
&& i != idxWorker
&& pGip->aCPUs[i].enmState == SUPGIPCPUSTATE_ONLINE
&& pGip->aCPUs[i].i64TSCDelta != INT64_MAX
&& pGip->aCPUs[i].idCpu != NIL_RTCPUID
&& pGip->aCPUs[i].idCpu != idMaster /* paranoia starts here... */
&& pGip->aCPUs[i].idCpu != pGipCpuWorker->idCpu
&& pGip->aCPUs[i].idApic != pGipCpuWorker->idApic
&& pGip->aCPUs[i].idApic != pGipCpuMaster->idApic
&& RTMpIsCpuOnline(pGip->aCPUs[i].idCpu))
{
iGipCpuMaster = i;
pGipCpuMaster = &pGip->aCPUs[i];
idMaster = pGipCpuMaster->idCpu;
break;
}
}
if (RTCpuSetIsMemberByIndex(&pGip->OnlineCpuSet, pGipCpuWorker->iCpuSet))
{
/*
* Initialize data package for the RTMpOnPair callback.
*/
PSUPDRVGIPTSCDELTARGS pArgs = (PSUPDRVGIPTSCDELTARGS)RTMemAllocZ(sizeof(*pArgs));
if (pArgs)
{
pArgs->pWorker = pGipCpuWorker;
pArgs->pMaster = pGipCpuMaster;
pArgs->pDevExt = pDevExt;
pArgs->pSyncMaster = NULL;
pArgs->pSyncWorker = NULL;
pArgs->cMaxTscTicks = ASMAtomicReadU64(&pGip->u64CpuHz) / 512; /* 1953 us */
/*
* Do the RTMpOnPair call. We reset i64TSCDelta first so we
* and supdrvMeasureTscDeltaCallback can use it as a success check.
*/
/** @todo Store the i64TSCDelta result in pArgs first? Perhaps deals with
* that when doing the restart loop reorg. */
ASMAtomicWriteS64(&pGipCpuWorker->i64TSCDelta, INT64_MAX);
rc = RTMpOnPair(pGipCpuMaster->idCpu, pGipCpuWorker->idCpu, RTMPON_F_CONCURRENT_EXEC,
supdrvMeasureTscDeltaCallback, pArgs, NULL);
if (RT_SUCCESS(rc))
{
#if 0
SUPR0Printf("mponpair ticks: %9llu %9llu max: %9llu iTry: %u%s\n", pArgs->cElapsedMasterTscTicks,
pArgs->cElapsedWorkerTscTicks, pArgs->cMaxTscTicks, pArgs->iTry,
pArgs->fTimedOut ? " timed out" :"");
#endif
#if 0
SUPR0Printf("rcVerify=%d iVerifyBadTscDiff=%lld cMinVerifyTscTicks=%lld cMaxVerifyTscTicks=%lld\n",
pArgs->rcVerify, pArgs->iVerifyBadTscDiff, pArgs->cMinVerifyTscTicks, pArgs->cMaxVerifyTscTicks);
#endif
if (RT_LIKELY(pGipCpuWorker->i64TSCDelta != INT64_MAX))
{
/*
* Work the TSC delta applicability rating. It starts
* optimistic in supdrvGipInit, we downgrade it here.
*/
SUPGIPUSETSCDELTA enmRating;
if ( pGipCpuWorker->i64TSCDelta > GIP_TSC_DELTA_THRESHOLD_ROUGHLY_ZERO
|| pGipCpuWorker->i64TSCDelta < -GIP_TSC_DELTA_THRESHOLD_ROUGHLY_ZERO)
enmRating = SUPGIPUSETSCDELTA_NOT_ZERO;
else if ( pGipCpuWorker->i64TSCDelta > GIP_TSC_DELTA_THRESHOLD_PRACTICALLY_ZERO
|| pGipCpuWorker->i64TSCDelta < -GIP_TSC_DELTA_THRESHOLD_PRACTICALLY_ZERO)
enmRating = SUPGIPUSETSCDELTA_ROUGHLY_ZERO;
else
enmRating = SUPGIPUSETSCDELTA_PRACTICALLY_ZERO;
if (pGip->enmUseTscDelta < enmRating)
{
AssertCompile(sizeof(pGip->enmUseTscDelta) == sizeof(uint32_t));
ASMAtomicWriteU32((uint32_t volatile *)&pGip->enmUseTscDelta, enmRating);
}
}
else
rc = VERR_SUPDRV_TSC_DELTA_MEASUREMENT_FAILED;
}
/** @todo return try-again if we get an offline CPU error. */
RTMemFree(pArgs);
}
else
rc = VERR_NO_MEMORY;
}
else
rc = VERR_CPU_OFFLINE;
/*
* We're done now.
*/
#ifdef SUPDRV_USE_MUTEX_FOR_GIP
rc2 = RTSemMutexRelease(pDevExt->mtxTscDelta); AssertRC(rc2);
#else
rc2 = RTSemFastMutexRelease(pDevExt->mtxTscDelta); AssertRC(rc2);
#endif
return rc;
}
/**
* Clears TSC delta related variables.
*
* Clears all TSC samples as well as the delta synchronization variable on the
* all the per-CPU structs. Optionally also clears the per-cpu deltas too.
*
* @param pDevExt Pointer to the device instance data.
* @param fClearDeltas Whether the deltas are also to be cleared.
*/
static void supdrvClearTscSamples(PSUPDRVDEVEXT pDevExt, bool fClearDeltas)
{
unsigned iCpu;
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
for (iCpu = 0; iCpu < pGip->cCpus; iCpu++)
{
PSUPGIPCPU pGipCpu = &pGip->aCPUs[iCpu];
ASMAtomicWriteU64(&pGipCpu->u64TSCSample, GIP_TSC_DELTA_RSVD);
if (fClearDeltas)
ASMAtomicWriteS64(&pGipCpu->i64TSCDelta, INT64_MAX);
}
}
/**
* Performs the initial measurements of the TSC deltas between CPUs.
*
* This is called by supdrvGipCreate or triggered by it if threaded.
*
* @returns VBox status code.
* @param pDevExt Pointer to the device instance data.
*
* @remarks Must be called only after supdrvGipInitOnCpu() as this function uses
* idCpu, GIP's online CPU set which are populated in
* supdrvGipInitOnCpu().
*/
static int supdrvMeasureInitialTscDeltas(PSUPDRVDEVEXT pDevExt)
{
PSUPGIPCPU pGipCpuMaster;
unsigned iCpu;
unsigned iOddEven;
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
uint32_t idxMaster = UINT32_MAX;
int rc = VINF_SUCCESS;
uint32_t cMpOnOffEvents = ASMAtomicReadU32(&pDevExt->cMpOnOffEvents);
Assert(pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED);
/*
* Pick the first CPU online as the master TSC and make it the new GIP master based
* on the APIC ID.
*
* Technically we can simply use "idGipMaster" but doing this gives us master as CPU 0
* in most cases making it nicer/easier for comparisons. It is safe to update the GIP
* master as this point since the sync/async timer isn't created yet.
*/
supdrvClearTscSamples(pDevExt, true /* fClearDeltas */);
for (iCpu = 0; iCpu < RT_ELEMENTS(pGip->aiCpuFromApicId); iCpu++)
{
uint16_t idxCpu = pGip->aiCpuFromApicId[iCpu];
if (idxCpu != UINT16_MAX)
{
PSUPGIPCPU pGipCpu = &pGip->aCPUs[idxCpu];
if (RTCpuSetIsMemberByIndex(&pGip->OnlineCpuSet, pGipCpu->iCpuSet))
{
idxMaster = idxCpu;
pGipCpu->i64TSCDelta = GIP_TSC_DELTA_INITIAL_MASTER_VALUE;
break;
}
}
}
AssertReturn(idxMaster != UINT32_MAX, VERR_CPU_NOT_FOUND);
pGipCpuMaster = &pGip->aCPUs[idxMaster];
ASMAtomicWriteSize(&pDevExt->idGipMaster, pGipCpuMaster->idCpu);
/*
* If there is only a single CPU online we have nothing to do.
*/
if (pGip->cOnlineCpus <= 1)
{
AssertReturn(pGip->cOnlineCpus > 0, VERR_INTERNAL_ERROR_5);
return VINF_SUCCESS;
}
/*
* Loop thru the GIP CPU array and get deltas for each CPU (except the
* master). We do the CPUs with the even numbered APIC IDs first so that
* we've got alternative master CPUs to pick from on hyper-threaded systems.
*/
for (iOddEven = 0; iOddEven < 2; iOddEven++)
{
for (iCpu = 0; iCpu < pGip->cCpus; iCpu++)
{
PSUPGIPCPU pGipCpuWorker = &pGip->aCPUs[iCpu];
if ( iCpu != idxMaster
&& (iOddEven > 0 || (pGipCpuWorker->idApic & 1) == 0)
&& RTCpuSetIsMemberByIndex(&pDevExt->TscDeltaCpuSet, pGipCpuWorker->iCpuSet))
{
rc = supdrvMeasureTscDeltaOne(pDevExt, iCpu);
if (RT_FAILURE(rc))
{
SUPR0Printf("supdrvMeasureTscDeltaOne failed. rc=%d CPU[%u].idCpu=%u Master[%u].idCpu=%u\n", rc, iCpu,
pGipCpuWorker->idCpu, idxMaster, pDevExt->idGipMaster, pGipCpuMaster->idCpu);
break;
}
if (ASMAtomicReadU32(&pDevExt->cMpOnOffEvents) != cMpOnOffEvents)
{
SUPR0Printf("One or more CPUs transitioned between online & offline states. I'm confused, retry...\n");
rc = VERR_TRY_AGAIN;
break;
}
}
}
}
return rc;
}
#ifdef SUPDRV_USE_TSC_DELTA_THREAD
/**
* Switches the TSC-delta measurement thread into the butchered state.
*
* @returns VBox status code.
* @param pDevExt Pointer to the device instance data.
* @param fSpinlockHeld Whether the TSC-delta spinlock is held or not.
* @param pszFailed An error message to log.
* @param rcFailed The error code to exit the thread with.
*/
static int supdrvTscDeltaThreadButchered(PSUPDRVDEVEXT pDevExt, bool fSpinlockHeld, const char *pszFailed, int rcFailed)
{
if (!fSpinlockHeld)
RTSpinlockAcquire(pDevExt->hTscDeltaSpinlock);
pDevExt->enmTscDeltaThreadState = kTscDeltaThreadState_Butchered;
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
OSDBGPRINT(("supdrvTscDeltaThreadButchered: %s. rc=%Rrc\n", rcFailed));
return rcFailed;
}
/**
* The TSC-delta measurement thread.
*
* @returns VBox status code.
* @param hThread The thread handle.
* @param pvUser Opaque pointer to the device instance data.
*/
static DECLCALLBACK(int) supdrvTscDeltaThread(RTTHREAD hThread, void *pvUser)
{
PSUPDRVDEVEXT pDevExt = (PSUPDRVDEVEXT)pvUser;
bool fInitialMeasurement = true;
uint32_t cConsecutiveTimeouts = 0;
int rc = VERR_INTERNAL_ERROR_2;
for (;;)
{
/*
* Switch on the current state.
*/
SUPDRVTSCDELTATHREADSTATE enmState;
RTSpinlockAcquire(pDevExt->hTscDeltaSpinlock);
enmState = pDevExt->enmTscDeltaThreadState;
switch (enmState)
{
case kTscDeltaThreadState_Creating:
{
pDevExt->enmTscDeltaThreadState = kTscDeltaThreadState_Listening;
rc = RTSemEventSignal(pDevExt->hTscDeltaEvent);
if (RT_FAILURE(rc))
return supdrvTscDeltaThreadButchered(pDevExt, true /* fSpinlockHeld */, "RTSemEventSignal", rc);
/* fall thru */
}
case kTscDeltaThreadState_Listening:
{
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
/* Simple adaptive timeout. */
if (cConsecutiveTimeouts++ == 10)
{
if (pDevExt->cMsTscDeltaTimeout == 1) /* 10 ms */
pDevExt->cMsTscDeltaTimeout = 10;
else if (pDevExt->cMsTscDeltaTimeout == 10) /* +100 ms */
pDevExt->cMsTscDeltaTimeout = 100;
else if (pDevExt->cMsTscDeltaTimeout == 100) /* +1000 ms */
pDevExt->cMsTscDeltaTimeout = 500;
cConsecutiveTimeouts = 0;
}
rc = RTThreadUserWait(pDevExt->hTscDeltaThread, pDevExt->cMsTscDeltaTimeout);
if ( RT_FAILURE(rc)
&& rc != VERR_TIMEOUT)
return supdrvTscDeltaThreadButchered(pDevExt, false /* fSpinlockHeld */, "RTThreadUserWait", rc);
RTThreadUserReset(pDevExt->hTscDeltaThread);
break;
}
case kTscDeltaThreadState_WaitAndMeasure:
{
pDevExt->enmTscDeltaThreadState = kTscDeltaThreadState_Measuring;
rc = RTSemEventSignal(pDevExt->hTscDeltaEvent); /* (Safe on windows as long as spinlock isn't IRQ safe.) */
if (RT_FAILURE(rc))
return supdrvTscDeltaThreadButchered(pDevExt, true /* fSpinlockHeld */, "RTSemEventSignal", rc);
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
pDevExt->cMsTscDeltaTimeout = 1;
RTThreadSleep(1);
/* fall thru */
}
case kTscDeltaThreadState_Measuring:
{
cConsecutiveTimeouts = 0;
if (fInitialMeasurement)
{
int cTries = 8;
int cMsWaitPerTry = 10;
fInitialMeasurement = false;
do
{
rc = supdrvMeasureInitialTscDeltas(pDevExt);
if ( RT_SUCCESS(rc)
|| ( RT_FAILURE(rc)
&& rc != VERR_TRY_AGAIN
&& rc != VERR_CPU_OFFLINE))
{
break;
}
RTThreadSleep(cMsWaitPerTry);
} while (cTries-- > 0);
}
else
{
PSUPGLOBALINFOPAGE pGip = pDevExt->pGip;
unsigned iCpu;
/* Measure TSC-deltas only for the CPUs that are in the set. */
rc = VINF_SUCCESS;
for (iCpu = 0; iCpu < pGip->cCpus; iCpu++)
{
PSUPGIPCPU pGipCpuWorker = &pGip->aCPUs[iCpu];
if (RTCpuSetIsMemberByIndex(&pDevExt->TscDeltaCpuSet, pGipCpuWorker->iCpuSet))
{
if (pGipCpuWorker->i64TSCDelta == INT64_MAX)
{
int rc2 = supdrvMeasureTscDeltaOne(pDevExt, iCpu);
if (RT_FAILURE(rc2) && RT_SUCCESS(rc))
rc = rc2;
}
else
{
/*
* The thread/someone must've called SUPR0TscDeltaMeasureBySetIndex,
* mark the delta as fine to get the timer thread off our back.
*/
RTCpuSetDelByIndex(&pDevExt->TscDeltaCpuSet, pGipCpuWorker->iCpuSet);
RTCpuSetAddByIndex(&pDevExt->TscDeltaObtainedCpuSet, pGipCpuWorker->iCpuSet);
}
}
}
}
RTSpinlockAcquire(pDevExt->hTscDeltaSpinlock);
if (pDevExt->enmTscDeltaThreadState == kTscDeltaThreadState_Measuring)
pDevExt->enmTscDeltaThreadState = kTscDeltaThreadState_Listening;
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
Assert(rc != VERR_NOT_AVAILABLE); /* VERR_NOT_AVAILABLE is used as the initial value. */
ASMAtomicWriteS32(&pDevExt->rcTscDelta, rc);
break;
}
case kTscDeltaThreadState_Terminating:
pDevExt->enmTscDeltaThreadState = kTscDeltaThreadState_Destroyed;
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
return VINF_SUCCESS;
case kTscDeltaThreadState_Butchered:
default:
return supdrvTscDeltaThreadButchered(pDevExt, true /* fSpinlockHeld */, "Invalid state", VERR_INVALID_STATE);
}
}
return rc;
}
/**
* Waits for the TSC-delta measurement thread to respond to a state change.
*
* @returns VINF_SUCCESS on success, VERR_TIMEOUT if it doesn't respond in time,
* other error code on internal error.
*
* @param pThis Pointer to the grant service instance data.
* @param enmCurState The current state.
* @param enmNewState The new state we're waiting for it to enter.
*/
static int supdrvTscDeltaThreadWait(PSUPDRVDEVEXT pDevExt, SUPDRVTSCDELTATHREADSTATE enmCurState,
SUPDRVTSCDELTATHREADSTATE enmNewState)
{
/*
* Wait a short while for the expected state transition.
*/
int rc;
RTSemEventWait(pDevExt->hTscDeltaEvent, RT_MS_1SEC);
RTSpinlockAcquire(pDevExt->hTscDeltaSpinlock);
if (pDevExt->enmTscDeltaThreadState == enmNewState)
{
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
rc = VINF_SUCCESS;
}
else if (pDevExt->enmTscDeltaThreadState == enmCurState)
{
/*
* Wait longer if the state has not yet transitioned to the one we want.
*/
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
rc = RTSemEventWait(pDevExt->hTscDeltaEvent, 50 * RT_MS_1SEC);
if ( RT_SUCCESS(rc)
|| rc == VERR_TIMEOUT)
{
/*
* Check the state whether we've succeeded.
*/
SUPDRVTSCDELTATHREADSTATE enmState;
RTSpinlockAcquire(pDevExt->hTscDeltaSpinlock);
enmState = pDevExt->enmTscDeltaThreadState;
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
if (enmState == enmNewState)
rc = VINF_SUCCESS;
else if (enmState == enmCurState)
{
rc = VERR_TIMEOUT;
OSDBGPRINT(("supdrvTscDeltaThreadWait: timed out state transition. enmState=%d enmNewState=%d\n", enmState,
enmNewState));
}
else
{
rc = VERR_INTERNAL_ERROR;
OSDBGPRINT(("supdrvTscDeltaThreadWait: invalid state transition from %d to %d, expected %d\n", enmCurState,
enmState, enmNewState));
}
}
else
OSDBGPRINT(("supdrvTscDeltaThreadWait: RTSemEventWait failed. rc=%Rrc\n", rc));
}
else
{
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
OSDBGPRINT(("supdrvTscDeltaThreadWait: invalid state transition from %d to %d\n", enmCurState, enmNewState));
rc = VERR_INTERNAL_ERROR;
}
return rc;
}
/**
* Signals the TSC-delta thread to start measuring TSC-deltas.
*
* @param pDevExt Pointer to the device instance data.
*/
static void supdrvTscDeltaThreadStartMeasurement(PSUPDRVDEVEXT pDevExt)
{
if (RT_LIKELY(pDevExt->hTscDeltaThread != NIL_RTTHREAD))
{
RTSpinlockAcquire(pDevExt->hTscDeltaSpinlock);
if ( pDevExt->enmTscDeltaThreadState == kTscDeltaThreadState_Listening
|| pDevExt->enmTscDeltaThreadState == kTscDeltaThreadState_Measuring)
{
pDevExt->enmTscDeltaThreadState = kTscDeltaThreadState_WaitAndMeasure;
}
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
RTThreadUserSignal(pDevExt->hTscDeltaThread);
}
}
/**
* Terminates the actual thread running supdrvTscDeltaThread().
*
* This is an internal worker function for supdrvTscDeltaThreadInit() and
* supdrvTscDeltaTerm().
*
* @param pDevExt Pointer to the device instance data.
*/
static void supdrvTscDeltaThreadTerminate(PSUPDRVDEVEXT pDevExt)
{
int rc;
RTSpinlockAcquire(pDevExt->hTscDeltaSpinlock);
pDevExt->enmTscDeltaThreadState = kTscDeltaThreadState_Terminating;
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
RTThreadUserSignal(pDevExt->hTscDeltaThread);
rc = RTThreadWait(pDevExt->hTscDeltaThread, 50 * RT_MS_1SEC, NULL /* prc */);
if (RT_FAILURE(rc))
{
/* Signal a few more times before giving up. */
int cTriesLeft = 5;
while (--cTriesLeft > 0)
{
RTThreadUserSignal(pDevExt->hTscDeltaThread);
rc = RTThreadWait(pDevExt->hTscDeltaThread, 2 * RT_MS_1SEC, NULL /* prc */);
if (rc != VERR_TIMEOUT)
break;
}
}
}
/**
* Initializes and spawns the TSC-delta measurement thread.
*
* A thread is required for servicing re-measurement requests from events like
* CPUs coming online, suspend/resume etc. as it cannot be done synchronously
* under all contexts on all OSs.
*
* @returns VBox status code.
* @param pDevExt Pointer to the device instance data.
*
* @remarks Must only be called -after- initializing GIP and setting up MP
* notifications!
*/
static int supdrvTscDeltaThreadInit(PSUPDRVDEVEXT pDevExt)
{
int rc;
Assert(pDevExt->pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED);
rc = RTSpinlockCreate(&pDevExt->hTscDeltaSpinlock, RTSPINLOCK_FLAGS_INTERRUPT_UNSAFE, "VBoxTscSpnLck");
if (RT_SUCCESS(rc))
{
rc = RTSemEventCreate(&pDevExt->hTscDeltaEvent);
if (RT_SUCCESS(rc))
{
pDevExt->enmTscDeltaThreadState = kTscDeltaThreadState_Creating;
pDevExt->cMsTscDeltaTimeout = 1;
rc = RTThreadCreate(&pDevExt->hTscDeltaThread, supdrvTscDeltaThread, pDevExt, 0 /* cbStack */,
RTTHREADTYPE_DEFAULT, RTTHREADFLAGS_WAITABLE, "VBoxTscThread");
if (RT_SUCCESS(rc))
{
rc = supdrvTscDeltaThreadWait(pDevExt, kTscDeltaThreadState_Creating, kTscDeltaThreadState_Listening);
if (RT_SUCCESS(rc))
{
ASMAtomicWriteS32(&pDevExt->rcTscDelta, VERR_NOT_AVAILABLE);
return rc;
}
OSDBGPRINT(("supdrvTscDeltaInit: supdrvTscDeltaThreadWait failed. rc=%Rrc\n", rc));
supdrvTscDeltaThreadTerminate(pDevExt);
}
else
OSDBGPRINT(("supdrvTscDeltaInit: RTThreadCreate failed. rc=%Rrc\n", rc));
RTSemEventDestroy(pDevExt->hTscDeltaEvent);
pDevExt->hTscDeltaEvent = NIL_RTSEMEVENT;
}
else
OSDBGPRINT(("supdrvTscDeltaInit: RTSemEventCreate failed. rc=%Rrc\n", rc));
RTSpinlockDestroy(pDevExt->hTscDeltaSpinlock);
pDevExt->hTscDeltaSpinlock = NIL_RTSPINLOCK;
}
else
OSDBGPRINT(("supdrvTscDeltaInit: RTSpinlockCreate failed. rc=%Rrc\n", rc));
return rc;
}
/**
* Terminates the TSC-delta measurement thread and cleanup.
*
* @param pDevExt Pointer to the device instance data.
*/
static void supdrvTscDeltaTerm(PSUPDRVDEVEXT pDevExt)
{
if ( pDevExt->hTscDeltaSpinlock != NIL_RTSPINLOCK
&& pDevExt->hTscDeltaEvent != NIL_RTSEMEVENT)
{
supdrvTscDeltaThreadTerminate(pDevExt);
}
if (pDevExt->hTscDeltaSpinlock != NIL_RTSPINLOCK)
{
RTSpinlockDestroy(pDevExt->hTscDeltaSpinlock);
pDevExt->hTscDeltaSpinlock = NIL_RTSPINLOCK;
}
if (pDevExt->hTscDeltaEvent != NIL_RTSEMEVENT)
{
RTSemEventDestroy(pDevExt->hTscDeltaEvent);
pDevExt->hTscDeltaEvent = NIL_RTSEMEVENT;
}
ASMAtomicWriteS32(&pDevExt->rcTscDelta, VERR_NOT_AVAILABLE);
}
#endif /* SUPDRV_USE_TSC_DELTA_THREAD */
/**
* Measure the TSC delta for the CPU given by its CPU set index.
*
* @returns VBox status code.
* @retval VERR_INTERRUPTED if interrupted while waiting.
* @retval VERR_SUPDRV_TSC_DELTA_MEASUREMENT_FAILED if we were unable to get a
* measurment.
* @retval VERR_CPU_OFFLINE if the specified CPU is offline.
* @retval VERR_CPU_OFFLINE if the specified CPU is offline.
*
* @param pSession The caller's session. GIP must've been mapped.
* @param iCpuSet The CPU set index of the CPU to measure.
* @param fFlags Flags, SUP_TSCDELTA_MEASURE_F_XXX.
* @param cMsWaitRetry Number of milliseconds to wait between each retry.
* @param cMsWaitThread Number of milliseconds to wait for the thread to get
* ready.
* @param cTries Number of times to try, pass 0 for the default.
*/
SUPR0DECL(int) SUPR0TscDeltaMeasureBySetIndex(PSUPDRVSESSION pSession, uint32_t iCpuSet, uint32_t fFlags,
RTMSINTERVAL cMsWaitRetry, RTMSINTERVAL cMsWaitThread, uint32_t cTries)
{
PSUPDRVDEVEXT pDevExt;
PSUPGLOBALINFOPAGE pGip;
uint16_t iGipCpu;
int rc;
#ifdef SUPDRV_USE_TSC_DELTA_THREAD
uint64_t msTsStartWait;
uint32_t iWaitLoop;
#endif
/*
* Validate and adjust the input.
*/
AssertReturn(SUP_IS_SESSION_VALID(pSession), VERR_INVALID_PARAMETER);
if (!pSession->fGipReferenced)
return VERR_WRONG_ORDER;
pDevExt = pSession->pDevExt;
AssertReturn(SUP_IS_DEVEXT_VALID(pDevExt), VERR_INVALID_PARAMETER);
pGip = pDevExt->pGip;
AssertPtrReturn(pGip, VERR_INTERNAL_ERROR_2);
AssertReturn(iCpuSet < RTCPUSET_MAX_CPUS, VERR_INVALID_CPU_INDEX);
AssertReturn(iCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx), VERR_INVALID_CPU_INDEX);
iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet];
AssertReturn(iGipCpu < pGip->cCpus, VERR_INVALID_CPU_INDEX);
if (fFlags & ~SUP_TSCDELTA_MEASURE_F_VALID_MASK)
return VERR_INVALID_FLAGS;
/*
* The request is a noop if the TSC delta isn't being used.
*/
if (pGip->enmUseTscDelta <= SUPGIPUSETSCDELTA_ZERO_CLAIMED)
return VINF_SUCCESS;
if (cTries == 0)
cTries = 12;
else if (cTries > 256)
cTries = 256;
if (cMsWaitRetry == 0)
cMsWaitRetry = 2;
else if (cMsWaitRetry > 1000)
cMsWaitRetry = 1000;
#ifdef SUPDRV_USE_TSC_DELTA_THREAD
/*
* Has the TSC already been measured and we're not forced to redo it?
*/
if ( pGip->aCPUs[iGipCpu].i64TSCDelta != INT64_MAX
&& !(fFlags & SUP_TSCDELTA_MEASURE_F_FORCE))
return VINF_SUCCESS;
/*
* Asynchronous request? Forward it to the thread, no waiting.
*/
if (fFlags & SUP_TSCDELTA_MEASURE_F_ASYNC)
{
/** @todo Async. doesn't implement options like retries, waiting. We'll need
* to pass those options to the thread somehow and implement it in the
* thread. Check if anyone uses/needs fAsync before implementing this. */
RTSpinlockAcquire(pDevExt->hTscDeltaSpinlock);
RTCpuSetAddByIndex(&pDevExt->TscDeltaCpuSet, iCpuSet);
if ( pDevExt->enmTscDeltaThreadState == kTscDeltaThreadState_Listening
|| pDevExt->enmTscDeltaThreadState == kTscDeltaThreadState_Measuring)
{
pDevExt->enmTscDeltaThreadState = kTscDeltaThreadState_WaitAndMeasure;
rc = VINF_SUCCESS;
}
else if (pDevExt->enmTscDeltaThreadState != kTscDeltaThreadState_WaitAndMeasure)
rc = VERR_THREAD_IS_DEAD;
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
RTThreadUserSignal(pDevExt->hTscDeltaThread);
return VINF_SUCCESS;
}
/*
* If a TSC-delta measurement request is already being serviced by the thread,
* wait 'cTries' times if a retry-timeout is provided, otherwise bail as busy.
*/
msTsStartWait = RTTimeSystemMilliTS();
for (iWaitLoop = 0;; iWaitLoop++)
{
uint64_t cMsElapsed;
SUPDRVTSCDELTATHREADSTATE enmState;
RTSpinlockAcquire(pDevExt->hTscDeltaSpinlock);
enmState = pDevExt->enmTscDeltaThreadState;
RTSpinlockRelease(pDevExt->hTscDeltaSpinlock);
if (enmState == kTscDeltaThreadState_Measuring)
{ /* Must wait, the thread is busy. */ }
else if (enmState == kTscDeltaThreadState_WaitAndMeasure)
{ /* Must wait, this state only says what will happen next. */ }
else if (enmState == kTscDeltaThreadState_Terminating)
{ /* Must wait, this state only says what should happen next. */ }
else
break; /* All other states, the thread is either idly listening or dead. */
/* Wait or fail. */
if (cMsWaitThread == 0)
return VERR_SUPDRV_TSC_DELTA_MEASUREMENT_BUSY;
cMsElapsed = RTTimeSystemMilliTS() - msTsStartWait;
if (cMsElapsed >= cMsWaitThread)
return VERR_SUPDRV_TSC_DELTA_MEASUREMENT_BUSY;
rc = RTThreadSleep(RT_MIN((RTMSINTERVAL)(cMsWaitThread - cMsElapsed), RT_MIN(iWaitLoop + 1, 10)));
if (rc == VERR_INTERRUPTED)
return rc;
}
#endif /* SUPDRV_USE_TSC_DELTA_THREAD */
/*
* Try measure the TSC delta the given number of times.
*/
for (;;)
{
/* Unless we're forced to measure the delta, check whether it's done already. */
if ( !(fFlags & SUP_TSCDELTA_MEASURE_F_FORCE)
&& pGip->aCPUs[iGipCpu].i64TSCDelta != INT64_MAX)
{
rc = VINF_SUCCESS;
break;
}
/* Measure it. */
rc = supdrvMeasureTscDeltaOne(pDevExt, iGipCpu);
if (rc != VERR_SUPDRV_TSC_DELTA_MEASUREMENT_FAILED)
{
Assert(pGip->aCPUs[iGipCpu].i64TSCDelta != INT64_MAX || RT_FAILURE_NP(rc));
break;
}
/* Retry? */
if (cTries <= 1)
break;
cTries--;
/* Always delay between retries (be nice to the rest of the system
and avoid the BSOD hounds). */
rc = RTThreadSleep(cMsWaitRetry);
if (rc == VERR_INTERRUPTED)
break;
}
return rc;
}
/**
* Service a TSC-delta measurement request.
*
* @returns VBox status code.
* @param pDevExt Pointer to the device instance data.
* @param pSession The support driver session.
* @param pReq Pointer to the TSC-delta measurement request.
*/
int VBOXCALL supdrvIOCtl_TscDeltaMeasure(PSUPDRVDEVEXT pDevExt, PSUPDRVSESSION pSession, PSUPTSCDELTAMEASURE pReq)
{
uint32_t cTries;
uint32_t iCpuSet;
uint32_t fFlags;
RTMSINTERVAL cMsWaitRetry;
/*
* Validate and adjust/resolve the input so they can be passed onto SUPR0TscDeltaMeasureBySetIndex.
*/
AssertPtr(pDevExt); AssertPtr(pSession); AssertPtr(pReq); /* paranoia^2 */
if (pReq->u.In.idCpu == NIL_RTCPUID)
return VERR_INVALID_CPU_ID;
iCpuSet = RTMpCpuIdToSetIndex(pReq->u.In.idCpu);
if (iCpuSet >= RTCPUSET_MAX_CPUS)
return VERR_INVALID_CPU_ID;
cTries = pReq->u.In.cRetries == 0 ? 0 : (uint32_t)pReq->u.In.cRetries + 1;
cMsWaitRetry = RT_MAX(pReq->u.In.cMsWaitRetry, 5);
fFlags = 0;
if (pReq->u.In.fAsync)
fFlags |= SUP_TSCDELTA_MEASURE_F_ASYNC;
if (pReq->u.In.fForce)
fFlags |= SUP_TSCDELTA_MEASURE_F_FORCE;
return SUPR0TscDeltaMeasureBySetIndex(pSession, iCpuSet, fFlags, cMsWaitRetry,
cTries == 0 ? 5 * RT_MS_1SEC : cMsWaitRetry * cTries /*cMsWaitThread*/,
cTries);
}
/**
* Reads TSC with delta applied.
*
* Will try to resolve delta value INT64_MAX before applying it. This is the
* main purpose of this function, to handle the case where the delta needs to be
* determined.
*
* @returns VBox status code.
* @param pDevExt Pointer to the device instance data.
* @param pSession The support driver session.
* @param pReq Pointer to the TSC-read request.
*/
int VBOXCALL supdrvIOCtl_TscRead(PSUPDRVDEVEXT pDevExt, PSUPDRVSESSION pSession, PSUPTSCREAD pReq)
{
PSUPGLOBALINFOPAGE pGip;
int rc;
/*
* Validate. We require the client to have mapped GIP (no asserting on
* ring-3 preconditions).
*/
AssertPtr(pDevExt); AssertPtr(pReq); AssertPtr(pSession); /* paranoia^2 */
if (pSession->GipMapObjR3 == NIL_RTR0MEMOBJ)
return VERR_WRONG_ORDER;
pGip = pDevExt->pGip;
AssertReturn(pGip, VERR_INTERNAL_ERROR_2);
/*
* We're usually here because we need to apply delta, but we shouldn't be
* upset if the GIP is some different mode.
*/
if (pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_ZERO_CLAIMED)
{
uint32_t cTries = 0;
for (;;)
{
/*
* Start by gathering the data, using CLI for disabling preemption
* while we do that.
*/
RTCCUINTREG fEFlags = ASMIntDisableFlags();
int iCpuSet = RTMpCpuIdToSetIndex(RTMpCpuId());
int iGipCpu;
if (RT_LIKELY( (unsigned)iCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)
&& (iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet]) < pGip->cCpus ))
{
int64_t i64Delta = pGip->aCPUs[iGipCpu].i64TSCDelta;
pReq->u.Out.idApic = pGip->aCPUs[iGipCpu].idApic;
pReq->u.Out.u64AdjustedTsc = ASMReadTSC();
ASMSetFlags(fEFlags);
/*
* If we're lucky we've got a delta, but no predicitions here
* as this I/O control is normally only used when the TSC delta
* is set to INT64_MAX.
*/
if (i64Delta != INT64_MAX)
{
pReq->u.Out.u64AdjustedTsc -= i64Delta;
rc = VINF_SUCCESS;
break;
}
/* Give up after a few times. */
if (cTries >= 4)
{
rc = VWRN_SUPDRV_TSC_DELTA_MEASUREMENT_FAILED;
break;
}
/* Need to measure the delta an try again. */
rc = supdrvMeasureTscDeltaOne(pDevExt, iGipCpu);
Assert(pGip->aCPUs[iGipCpu].i64TSCDelta != INT64_MAX || RT_FAILURE_NP(rc));
/** @todo should probably delay on failure... dpc watchdogs */
}
else
{
/* This really shouldn't happen. */
AssertMsgFailed(("idCpu=%#x iCpuSet=%#x (%d)\n", RTMpCpuId(), iCpuSet, iCpuSet));
pReq->u.Out.idApic = ASMGetApicId();
pReq->u.Out.u64AdjustedTsc = ASMReadTSC();
ASMSetFlags(fEFlags);
rc = VERR_INTERNAL_ERROR_5; /** @todo change to warning. */
break;
}
}
}
else
{
/*
* No delta to apply. Easy. Deal with preemption the lazy way.
*/
RTCCUINTREG fEFlags = ASMIntDisableFlags();
int iCpuSet = RTMpCpuIdToSetIndex(RTMpCpuId());
int iGipCpu;
if (RT_LIKELY( (unsigned)iCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)
&& (iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet]) < pGip->cCpus ))
pReq->u.Out.idApic = pGip->aCPUs[iGipCpu].idApic;
else
pReq->u.Out.idApic = ASMGetApicId();
pReq->u.Out.u64AdjustedTsc = ASMReadTSC();
ASMSetFlags(fEFlags);
rc = VINF_SUCCESS;
}
return rc;
}