VirtualBox

source: vbox/trunk/src/VBox/VMM/VMMAll/TMAllVirtual.cpp@ 31596

Last change on this file since 31596 was 29250, checked in by vboxsync, 15 years ago

iprt/asm*.h: split out asm-math.h, don't include asm-*.h from asm.h, don't include asm.h from sup.h. Fixed a couple file headers.

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1/* $Id: TMAllVirtual.cpp 29250 2010-05-09 17:53:58Z vboxsync $ */
2/** @file
3 * TM - Timeout Manager, Virtual Time, All Contexts.
4 */
5
6/*
7 * Copyright (C) 2006-2007 Oracle Corporation
8 *
9 * This file is part of VirtualBox Open Source Edition (OSE), as
10 * available from http://www.virtualbox.org. This file is free software;
11 * you can redistribute it and/or modify it under the terms of the GNU
12 * General Public License (GPL) as published by the Free Software
13 * Foundation, in version 2 as it comes in the "COPYING" file of the
14 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16 */
17
18
19/*******************************************************************************
20* Header Files *
21*******************************************************************************/
22#define LOG_GROUP LOG_GROUP_TM
23#include <VBox/tm.h>
24#ifdef IN_RING3
25# include <VBox/rem.h>
26# include <iprt/thread.h>
27#endif
28#include "TMInternal.h"
29#include <VBox/vm.h>
30#include <VBox/vmm.h>
31#include <VBox/err.h>
32#include <VBox/log.h>
33#include <VBox/sup.h>
34
35#include <iprt/time.h>
36#include <iprt/assert.h>
37#include <iprt/asm.h>
38#include <iprt/asm-math.h>
39
40
41
42/**
43 * Helper function that's used by the assembly routines when something goes bust.
44 *
45 * @param pData Pointer to the data structure.
46 * @param u64NanoTS The calculated nano ts.
47 * @param u64DeltaPrev The delta relative to the previously returned timestamp.
48 * @param u64PrevNanoTS The previously returned timestamp (as it was read it).
49 */
50DECLEXPORT(void) tmVirtualNanoTSBad(PRTTIMENANOTSDATA pData, uint64_t u64NanoTS, uint64_t u64DeltaPrev, uint64_t u64PrevNanoTS)
51{
52 //PVM pVM = (PVM)((uint8_t *)pData - RT_OFFSETOF(VM, CTXALLSUFF(s.tm.VirtualGetRawData)));
53 pData->cBadPrev++;
54 if ((int64_t)u64DeltaPrev < 0)
55 LogRel(("TM: u64DeltaPrev=%RI64 u64PrevNanoTS=0x%016RX64 u64NanoTS=0x%016RX64\n",
56 u64DeltaPrev, u64PrevNanoTS, u64NanoTS));
57 else
58 Log(("TM: u64DeltaPrev=%RI64 u64PrevNanoTS=0x%016RX64 u64NanoTS=0x%016RX64 (debugging?)\n",
59 u64DeltaPrev, u64PrevNanoTS, u64NanoTS));
60}
61
62
63/**
64 * Called the first time somebody asks for the time or when the GIP
65 * is mapped/unmapped.
66 *
67 * This should never ever happen.
68 */
69DECLEXPORT(uint64_t) tmVirtualNanoTSRediscover(PRTTIMENANOTSDATA pData)
70{
71 //PVM pVM = (PVM)((uint8_t *)pData - RT_OFFSETOF(VM, CTXALLSUFF(s.tm.VirtualGetRawData)));
72 PSUPGLOBALINFOPAGE pGip = g_pSUPGlobalInfoPage;
73 AssertFatalMsgFailed(("pGip=%p u32Magic=%#x\n", pGip, VALID_PTR(pGip) ? pGip->u32Magic : 0));
74 return 0; /* gcc false positive warning */
75}
76
77
78#if 1
79
80/**
81 * Wrapper around the IPRT GIP time methods.
82 */
83DECLINLINE(uint64_t) tmVirtualGetRawNanoTS(PVM pVM)
84{
85#ifdef IN_RING3
86 return CTXALLSUFF(pVM->tm.s.pfnVirtualGetRaw)(&CTXALLSUFF(pVM->tm.s.VirtualGetRawData));
87# else /* !IN_RING3 */
88 uint32_t cPrevSteps = pVM->tm.s.CTX_SUFF(VirtualGetRawData).c1nsSteps;
89 uint64_t u64 = pVM->tm.s.CTX_SUFF(pfnVirtualGetRaw)(&pVM->tm.s.CTX_SUFF(VirtualGetRawData));
90 if (cPrevSteps != pVM->tm.s.CTX_SUFF(VirtualGetRawData).c1nsSteps)
91 VMCPU_FF_SET(VMMGetCpu(pVM), VMCPU_FF_TO_R3);
92 return u64;
93# endif /* !IN_RING3 */
94}
95
96#else
97
98/**
99 * This is (mostly) the same as rtTimeNanoTSInternal() except
100 * for the two globals which live in TM.
101 *
102 * @returns Nanosecond timestamp.
103 * @param pVM The VM handle.
104 */
105static uint64_t tmVirtualGetRawNanoTS(PVM pVM)
106{
107 uint64_t u64Delta;
108 uint32_t u32NanoTSFactor0;
109 uint64_t u64TSC;
110 uint64_t u64NanoTS;
111 uint32_t u32UpdateIntervalTSC;
112 uint64_t u64PrevNanoTS;
113
114 /*
115 * Read the GIP data and the previous value.
116 */
117 for (;;)
118 {
119 uint32_t u32TransactionId;
120 PSUPGLOBALINFOPAGE pGip = g_pSUPGlobalInfoPage;
121#ifdef IN_RING3
122 if (RT_UNLIKELY(!pGip || pGip->u32Magic != SUPGLOBALINFOPAGE_MAGIC))
123 return RTTimeSystemNanoTS();
124#endif
125
126 if (pGip->u32Mode != SUPGIPMODE_ASYNC_TSC)
127 {
128 u32TransactionId = pGip->aCPUs[0].u32TransactionId;
129#ifdef RT_OS_L4
130 Assert((u32TransactionId & 1) == 0);
131#endif
132 u32UpdateIntervalTSC = pGip->aCPUs[0].u32UpdateIntervalTSC;
133 u64NanoTS = pGip->aCPUs[0].u64NanoTS;
134 u64TSC = pGip->aCPUs[0].u64TSC;
135 u32NanoTSFactor0 = pGip->u32UpdateIntervalNS;
136 u64Delta = ASMReadTSC();
137 u64PrevNanoTS = ASMAtomicReadU64(&pVM->tm.s.u64VirtualRawPrev);
138 if (RT_UNLIKELY( pGip->aCPUs[0].u32TransactionId != u32TransactionId
139 || (u32TransactionId & 1)))
140 continue;
141 }
142 else
143 {
144 /* SUPGIPMODE_ASYNC_TSC */
145 PSUPGIPCPU pGipCpu;
146
147 uint8_t u8ApicId = ASMGetApicId();
148 if (RT_LIKELY(u8ApicId < RT_ELEMENTS(pGip->aCPUs)))
149 pGipCpu = &pGip->aCPUs[u8ApicId];
150 else
151 {
152 AssertMsgFailed(("%x\n", u8ApicId));
153 pGipCpu = &pGip->aCPUs[0];
154 }
155
156 u32TransactionId = pGipCpu->u32TransactionId;
157#ifdef RT_OS_L4
158 Assert((u32TransactionId & 1) == 0);
159#endif
160 u32UpdateIntervalTSC = pGipCpu->u32UpdateIntervalTSC;
161 u64NanoTS = pGipCpu->u64NanoTS;
162 u64TSC = pGipCpu->u64TSC;
163 u32NanoTSFactor0 = pGip->u32UpdateIntervalNS;
164 u64Delta = ASMReadTSC();
165 u64PrevNanoTS = ASMAtomicReadU64(&pVM->tm.s.u64VirtualRawPrev);
166#ifdef IN_RC
167 Assert(!(ASMGetFlags() & X86_EFL_IF));
168#else
169 if (RT_UNLIKELY(u8ApicId != ASMGetApicId()))
170 continue;
171 if (RT_UNLIKELY( pGipCpu->u32TransactionId != u32TransactionId
172 || (u32TransactionId & 1)))
173 continue;
174#endif
175 }
176 break;
177 }
178
179 /*
180 * Calc NanoTS delta.
181 */
182 u64Delta -= u64TSC;
183 if (u64Delta > u32UpdateIntervalTSC)
184 {
185 /*
186 * We've expired the interval, cap it. If we're here for the 2nd
187 * time without any GIP update inbetween, the checks against
188 * pVM->tm.s.u64VirtualRawPrev below will force 1ns stepping.
189 */
190 u64Delta = u32UpdateIntervalTSC;
191 }
192#if !defined(_MSC_VER) || defined(RT_ARCH_AMD64) /* GCC makes very pretty code from these two inline calls, while MSC cannot. */
193 u64Delta = ASMMult2xU32RetU64((uint32_t)u64Delta, u32NanoTSFactor0);
194 u64Delta = ASMDivU64ByU32RetU32(u64Delta, u32UpdateIntervalTSC);
195#else
196 __asm
197 {
198 mov eax, dword ptr [u64Delta]
199 mul dword ptr [u32NanoTSFactor0]
200 div dword ptr [u32UpdateIntervalTSC]
201 mov dword ptr [u64Delta], eax
202 xor edx, edx
203 mov dword ptr [u64Delta + 4], edx
204 }
205#endif
206
207 /*
208 * Calculate the time and compare it with the previously returned value.
209 *
210 * Since this function is called *very* frequently when the VM is running
211 * and then mostly on EMT, we can restrict the valid range of the delta
212 * (-1s to 2*GipUpdates) and simplify/optimize the default path.
213 */
214 u64NanoTS += u64Delta;
215 uint64_t u64DeltaPrev = u64NanoTS - u64PrevNanoTS;
216 if (RT_LIKELY(u64DeltaPrev < 1000000000 /* 1s */))
217 /* frequent - less than 1s since last call. */;
218 else if ( (int64_t)u64DeltaPrev < 0
219 && (int64_t)u64DeltaPrev + u32NanoTSFactor0 * 2 > 0)
220 {
221 /* occasional - u64NanoTS is in the 'past' relative to previous returns. */
222 ASMAtomicIncU32(&pVM->tm.s.CTX_SUFF(VirtualGetRawData).c1nsSteps);
223 u64NanoTS = u64PrevNanoTS + 1;
224#ifndef IN_RING3
225 VM_FF_SET(pVM, VM_FF_TO_R3); /* S10 hack */
226#endif
227 }
228 else if (u64PrevNanoTS)
229 {
230 /* Something has gone bust, if negative offset it's real bad. */
231 ASMAtomicIncU32(&pVM->tm.s.CTX_SUFF(VirtualGetRawData).cBadPrev);
232 if ((int64_t)u64DeltaPrev < 0)
233 LogRel(("TM: u64DeltaPrev=%RI64 u64PrevNanoTS=0x%016RX64 u64NanoTS=0x%016RX64 u64Delta=%#RX64\n",
234 u64DeltaPrev, u64PrevNanoTS, u64NanoTS, u64Delta));
235 else
236 Log(("TM: u64DeltaPrev=%RI64 u64PrevNanoTS=0x%016RX64 u64NanoTS=0x%016RX64 u64Delta=%#RX64 (debugging?)\n",
237 u64DeltaPrev, u64PrevNanoTS, u64NanoTS, u64Delta));
238#ifdef DEBUG_bird
239 /** @todo there are some hickups during boot and reset that can cause 2-5 seconds delays. Investigate... */
240 AssertMsg(u64PrevNanoTS > UINT64_C(100000000000) /* 100s */,
241 ("u64DeltaPrev=%RI64 u64PrevNanoTS=0x%016RX64 u64NanoTS=0x%016RX64 u64Delta=%#RX64\n",
242 u64DeltaPrev, u64PrevNanoTS, u64NanoTS, u64Delta));
243#endif
244 }
245 /* else: We're resuming (see TMVirtualResume). */
246 if (RT_LIKELY(ASMAtomicCmpXchgU64(&pVM->tm.s.u64VirtualRawPrev, u64NanoTS, u64PrevNanoTS)))
247 return u64NanoTS;
248
249 /*
250 * Attempt updating the previous value, provided we're still ahead of it.
251 *
252 * There is no point in recalculating u64NanoTS because we got preemted or if
253 * we raced somebody while the GIP was updated, since these are events
254 * that might occure at any point in the return path as well.
255 */
256 for (int cTries = 50;;)
257 {
258 u64PrevNanoTS = ASMAtomicReadU64(&pVM->tm.s.u64VirtualRawPrev);
259 if (u64PrevNanoTS >= u64NanoTS)
260 break;
261 if (ASMAtomicCmpXchgU64(&pVM->tm.s.u64VirtualRawPrev, u64NanoTS, u64PrevNanoTS))
262 break;
263 AssertBreak(--cTries <= 0);
264 if (cTries < 25 && !VM_IS_EMT(pVM)) /* give up early */
265 break;
266 }
267
268 return u64NanoTS;
269}
270
271#endif
272
273
274/**
275 * Get the time when we're not running at 100%
276 *
277 * @returns The timestamp.
278 * @param pVM The VM handle.
279 */
280static uint64_t tmVirtualGetRawNonNormal(PVM pVM)
281{
282 /*
283 * Recalculate the RTTimeNanoTS() value for the period where
284 * warp drive has been enabled.
285 */
286 uint64_t u64 = tmVirtualGetRawNanoTS(pVM);
287 u64 -= pVM->tm.s.u64VirtualWarpDriveStart;
288 u64 *= pVM->tm.s.u32VirtualWarpDrivePercentage;
289 u64 /= 100;
290 u64 += pVM->tm.s.u64VirtualWarpDriveStart;
291
292 /*
293 * Now we apply the virtual time offset.
294 * (Which is the negated tmVirtualGetRawNanoTS() value for when the virtual
295 * machine started if it had been running continuously without any suspends.)
296 */
297 u64 -= pVM->tm.s.u64VirtualOffset;
298 return u64;
299}
300
301
302/**
303 * Get the raw virtual time.
304 *
305 * @returns The current time stamp.
306 * @param pVM The VM handle.
307 */
308DECLINLINE(uint64_t) tmVirtualGetRaw(PVM pVM)
309{
310 if (RT_LIKELY(!pVM->tm.s.fVirtualWarpDrive))
311 return tmVirtualGetRawNanoTS(pVM) - pVM->tm.s.u64VirtualOffset;
312 return tmVirtualGetRawNonNormal(pVM);
313}
314
315
316/**
317 * Inlined version of tmVirtualGetEx.
318 */
319DECLINLINE(uint64_t) tmVirtualGet(PVM pVM, bool fCheckTimers)
320{
321 uint64_t u64;
322 if (RT_LIKELY(pVM->tm.s.cVirtualTicking))
323 {
324 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualGet);
325 u64 = tmVirtualGetRaw(pVM);
326
327 /*
328 * Use the chance to check for expired timers.
329 */
330 if (fCheckTimers)
331 {
332 PVMCPU pVCpuDst = &pVM->aCpus[pVM->tm.s.idTimerCpu];
333 if ( !VMCPU_FF_ISSET(pVCpuDst, VMCPU_FF_TIMER)
334 && !pVM->tm.s.fRunningQueues
335 && ( pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL].u64Expire <= u64
336 || ( pVM->tm.s.fVirtualSyncTicking
337 && pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL_SYNC].u64Expire <= u64 - pVM->tm.s.offVirtualSync
338 )
339 )
340 && !pVM->tm.s.fRunningQueues
341 )
342 {
343 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualGetSetFF);
344 Log5(("TMAllVirtual(%u): FF: %d -> 1\n", __LINE__, VMCPU_FF_ISPENDING(pVCpuDst, VMCPU_FF_TIMER)));
345 VMCPU_FF_SET(pVCpuDst, VMCPU_FF_TIMER);
346#ifdef IN_RING3
347 REMR3NotifyTimerPending(pVM, pVCpuDst);
348 VMR3NotifyCpuFFU(pVCpuDst->pUVCpu, VMNOTIFYFF_FLAGS_DONE_REM);
349#endif
350 }
351 }
352 }
353 else
354 u64 = pVM->tm.s.u64Virtual;
355 return u64;
356}
357
358
359/**
360 * Gets the current TMCLOCK_VIRTUAL time
361 *
362 * @returns The timestamp.
363 * @param pVM VM handle.
364 *
365 * @remark While the flow of time will never go backwards, the speed of the
366 * progress varies due to inaccurate RTTimeNanoTS and TSC. The latter can be
367 * influenced by power saving (SpeedStep, PowerNow!), while the former
368 * makes use of TSC and kernel timers.
369 */
370VMM_INT_DECL(uint64_t) TMVirtualGet(PVM pVM)
371{
372 return tmVirtualGet(pVM, true /* check timers */);
373}
374
375
376/**
377 * Gets the current TMCLOCK_VIRTUAL time without checking
378 * timers or anything.
379 *
380 * Meaning, this has no side effect on FFs like TMVirtualGet may have.
381 *
382 * @returns The timestamp.
383 * @param pVM VM handle.
384 *
385 * @remarks See TMVirtualGet.
386 */
387VMM_INT_DECL(uint64_t) TMVirtualGetNoCheck(PVM pVM)
388{
389 return tmVirtualGet(pVM, false /*fCheckTimers*/);
390}
391
392
393/**
394 * tmVirtualSyncGetLocked worker for handling catch-up when owning the lock.
395 *
396 * @returns The timestamp.
397 * @param pVM VM handle.
398 * @param u64 raw virtual time.
399 * @param off offVirtualSync.
400 */
401DECLINLINE(uint64_t) tmVirtualSyncGetHandleCatchUpLocked(PVM pVM, uint64_t u64, uint64_t off)
402{
403 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLocked);
404
405 /*
406 * Don't make updates until we've check the timer qeueue.
407 */
408 bool fUpdatePrev = true;
409 bool fUpdateOff = true;
410 bool fStop = false;
411 const uint64_t u64Prev = pVM->tm.s.u64VirtualSyncCatchUpPrev;
412 uint64_t u64Delta = u64 - u64Prev;
413 if (RT_LIKELY(!(u64Delta >> 32)))
414 {
415 uint64_t u64Sub = ASMMultU64ByU32DivByU32(u64Delta, pVM->tm.s.u32VirtualSyncCatchUpPercentage, 100);
416 if (off > u64Sub + pVM->tm.s.offVirtualSyncGivenUp)
417 {
418 off -= u64Sub;
419 Log4(("TM: %'RU64/-%'8RU64: sub %RU32 [vsghcul]\n", u64 - off, off - pVM->tm.s.offVirtualSyncGivenUp, u64Sub));
420 }
421 else
422 {
423 /* we've completely caught up. */
424 STAM_PROFILE_ADV_STOP(&pVM->tm.s.StatVirtualSyncCatchup, c);
425 off = pVM->tm.s.offVirtualSyncGivenUp;
426 fStop = true;
427 Log4(("TM: %'RU64/0: caught up [vsghcul]\n", u64));
428 }
429 }
430 else
431 {
432 /* More than 4 seconds since last time (or negative), ignore it. */
433 fUpdateOff = false;
434 fUpdatePrev = !(u64Delta & RT_BIT_64(63));
435 Log(("TMVirtualGetSync: u64Delta=%RX64\n", u64Delta));
436 }
437
438 /*
439 * Complete the calculation of the current TMCLOCK_VIRTUAL_SYNC time. The current
440 * approach is to never pass the head timer. So, when we do stop the clock and
441 * set the timer pending flag.
442 */
443 u64 -= off;
444 uint64_t u64Expire = ASMAtomicReadU64(&pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL_SYNC].u64Expire);
445 if (u64 < u64Expire)
446 {
447 if (fUpdateOff)
448 ASMAtomicWriteU64(&pVM->tm.s.offVirtualSync, off);
449 if (fStop)
450 ASMAtomicWriteBool(&pVM->tm.s.fVirtualSyncCatchUp, false);
451 if (fUpdatePrev)
452 ASMAtomicWriteU64(&pVM->tm.s.u64VirtualSyncCatchUpPrev, u64);
453 tmVirtualSyncUnlock(pVM);
454 }
455 else
456 {
457 u64 = u64Expire;
458 ASMAtomicWriteU64(&pVM->tm.s.u64VirtualSync, u64);
459 ASMAtomicWriteBool(&pVM->tm.s.fVirtualSyncTicking, false);
460
461 VM_FF_SET(pVM, VM_FF_TM_VIRTUAL_SYNC);
462 PVMCPU pVCpuDst = &pVM->aCpus[pVM->tm.s.idTimerCpu];
463 VMCPU_FF_SET(pVCpuDst, VMCPU_FF_TIMER);
464 Log5(("TMAllVirtual(%u): FF: %d -> 1\n", __LINE__, VMCPU_FF_ISPENDING(pVCpuDst, VMCPU_FF_TIMER)));
465 Log4(("TM: %'RU64/-%'8RU64: exp tmr=>ff [vsghcul]\n", u64, pVM->tm.s.offVirtualSync - pVM->tm.s.offVirtualSyncGivenUp));
466 tmVirtualSyncUnlock(pVM);
467
468#ifdef IN_RING3
469 REMR3NotifyTimerPending(pVM, pVCpuDst);
470 VMR3NotifyCpuFFU(pVCpuDst->pUVCpu, VMNOTIFYFF_FLAGS_DONE_REM);
471#endif
472 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetSetFF);
473 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetExpired);
474 }
475 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLocked);
476
477 Log6(("tmVirtualSyncGetHandleCatchUpLocked -> %'RU64\n", u64));
478 return u64;
479}
480
481
482/**
483 * tmVirtualSyncGetEx worker for when we get the lock.
484 *
485 * @returns timesamp.
486 * @param pVM The VM handle.
487 * @param u64 The virtual clock timestamp.
488 */
489DECLINLINE(uint64_t) tmVirtualSyncGetLocked(PVM pVM, uint64_t u64)
490{
491 /*
492 * Not ticking?
493 */
494 if (!pVM->tm.s.fVirtualSyncTicking)
495 {
496 u64 = ASMAtomicUoReadU64(&pVM->tm.s.u64VirtualSync);
497 tmVirtualSyncUnlock(pVM);
498 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLocked);
499 Log6(("tmVirtualSyncGetLocked -> %'RU64 [stopped]\n", u64));
500 return u64;
501 }
502
503 /*
504 * Handle catch up in a separate function.
505 */
506 uint64_t off = ASMAtomicUoReadU64(&pVM->tm.s.offVirtualSync);
507 if (ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
508 return tmVirtualSyncGetHandleCatchUpLocked(pVM, u64, off);
509
510 /*
511 * Complete the calculation of the current TMCLOCK_VIRTUAL_SYNC time. The current
512 * approach is to never pass the head timer. So, when we do stop the clock and
513 * set the timer pending flag.
514 */
515 u64 -= off;
516 uint64_t u64Expire = ASMAtomicReadU64(&pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL_SYNC].u64Expire);
517 if (u64 < u64Expire)
518 tmVirtualSyncUnlock(pVM);
519 else
520 {
521 u64 = u64Expire;
522 ASMAtomicWriteU64(&pVM->tm.s.u64VirtualSync, u64);
523 ASMAtomicWriteBool(&pVM->tm.s.fVirtualSyncTicking, false);
524
525 VM_FF_SET(pVM, VM_FF_TM_VIRTUAL_SYNC);
526 PVMCPU pVCpuDst = &pVM->aCpus[pVM->tm.s.idTimerCpu];
527 VMCPU_FF_SET(pVCpuDst, VMCPU_FF_TIMER);
528 Log5(("TMAllVirtual(%u): FF: %d -> 1\n", __LINE__, !!VMCPU_FF_ISPENDING(pVCpuDst, VMCPU_FF_TIMER)));
529 Log4(("TM: %'RU64/-%'8RU64: exp tmr=>ff [vsgl]\n", u64, pVM->tm.s.offVirtualSync - pVM->tm.s.offVirtualSyncGivenUp));
530 tmVirtualSyncUnlock(pVM);
531
532#ifdef IN_RING3
533 REMR3NotifyTimerPending(pVM, pVCpuDst);
534 VMR3NotifyCpuFFU(pVCpuDst->pUVCpu, VMNOTIFYFF_FLAGS_DONE_REM);
535#endif
536 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetSetFF);
537 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetExpired);
538 }
539 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLocked);
540 Log6(("tmVirtualSyncGetLocked -> %'RU64\n", u64));
541 return u64;
542}
543
544
545/**
546 * Gets the current TMCLOCK_VIRTUAL_SYNC time.
547 *
548 * @returns The timestamp.
549 * @param pVM VM handle.
550 * @param fCheckTimers Check timers or not
551 * @thread EMT.
552 */
553DECLINLINE(uint64_t) tmVirtualSyncGetEx(PVM pVM, bool fCheckTimers)
554{
555 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGet);
556
557 if (!pVM->tm.s.fVirtualSyncTicking)
558 return pVM->tm.s.u64VirtualSync;
559
560 /*
561 * Query the virtual clock and do the usual expired timer check.
562 */
563 Assert(pVM->tm.s.cVirtualTicking);
564 uint64_t u64 = tmVirtualGetRaw(pVM);
565 if (fCheckTimers)
566 {
567 PVMCPU pVCpuDst = &pVM->aCpus[pVM->tm.s.idTimerCpu];
568 if ( !VMCPU_FF_ISSET(pVCpuDst, VMCPU_FF_TIMER)
569 && pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL].u64Expire <= u64)
570 {
571 Log5(("TMAllVirtual(%u): FF: 0 -> 1\n", __LINE__));
572 VMCPU_FF_SET(pVCpuDst, VMCPU_FF_TIMER);
573#ifdef IN_RING3
574 REMR3NotifyTimerPending(pVM, pVCpuDst);
575 VMR3NotifyCpuFFU(pVCpuDst->pUVCpu, VMNOTIFYFF_FLAGS_DONE_REM /** @todo |VMNOTIFYFF_FLAGS_POKE*/);
576#endif
577 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetSetFF);
578 }
579 }
580
581 /*
582 * When the clock is ticking, not doing catch ups and not running into an
583 * expired time, we can get away without locking. Try this first.
584 */
585 uint64_t off;
586 if (ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncTicking))
587 {
588 if (!ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
589 {
590 off = ASMAtomicReadU64(&pVM->tm.s.offVirtualSync);
591 if (RT_LIKELY( ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncTicking)
592 && !ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncCatchUp)
593 && off == ASMAtomicReadU64(&pVM->tm.s.offVirtualSync)))
594 {
595 off = u64 - off;
596 if (off < ASMAtomicReadU64(&pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL_SYNC].u64Expire))
597 {
598 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLockless);
599 Log6(("tmVirtualSyncGetEx -> %'RU64 [lockless]\n", off));
600 return off;
601 }
602 }
603 }
604 }
605 else
606 {
607 off = ASMAtomicReadU64(&pVM->tm.s.u64VirtualSync);
608 if (RT_LIKELY(!ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncTicking)))
609 {
610 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLockless);
611 Log6(("tmVirtualSyncGetEx -> %'RU64 [lockless/stopped]\n", off));
612 return off;
613 }
614 }
615
616 /*
617 * Read the offset and adjust if we're playing catch-up.
618 *
619 * The catch-up adjusting work by us decrementing the offset by a percentage of
620 * the time elapsed since the previous TMVirtualGetSync call.
621 *
622 * It's possible to get a very long or even negative interval between two read
623 * for the following reasons:
624 * - Someone might have suspended the process execution, frequently the case when
625 * debugging the process.
626 * - We might be on a different CPU which TSC isn't quite in sync with the
627 * other CPUs in the system.
628 * - Another thread is racing us and we might have been preemnted while inside
629 * this function.
630 *
631 * Assuming nano second virtual time, we can simply ignore any intervals which has
632 * any of the upper 32 bits set.
633 */
634 AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
635 int cOuterTries = 42;
636 for (;; cOuterTries--)
637 {
638 /* Try grab the lock, things get simpler when owning the lock. */
639 int rcLock = tmVirtualSyncTryLock(pVM);
640 if (RT_SUCCESS_NP(rcLock))
641 return tmVirtualSyncGetLocked(pVM, u64);
642
643 /* Re-check the ticking flag. */
644 if (!ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncTicking))
645 {
646 off = ASMAtomicReadU64(&pVM->tm.s.u64VirtualSync);
647 if ( ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncTicking)
648 && cOuterTries > 0)
649 continue;
650 Log6(("tmVirtualSyncGetEx -> %'RU64 [stopped]\n", off));
651 return off;
652 }
653
654 off = ASMAtomicReadU64(&pVM->tm.s.offVirtualSync);
655 if (ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
656 {
657 /* No changes allowed, try get a consistent set of parameters. */
658 uint64_t const u64Prev = ASMAtomicReadU64(&pVM->tm.s.u64VirtualSyncCatchUpPrev);
659 uint64_t const offGivenUp = ASMAtomicReadU64(&pVM->tm.s.offVirtualSyncGivenUp);
660 uint32_t const u32Pct = ASMAtomicReadU32(&pVM->tm.s.u32VirtualSyncCatchUpPercentage);
661 if ( ( u64Prev == ASMAtomicReadU64(&pVM->tm.s.u64VirtualSyncCatchUpPrev)
662 && offGivenUp == ASMAtomicReadU64(&pVM->tm.s.offVirtualSyncGivenUp)
663 && u32Pct == ASMAtomicReadU32(&pVM->tm.s.u32VirtualSyncCatchUpPercentage)
664 && ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
665 || cOuterTries <= 0)
666 {
667 uint64_t u64Delta = u64 - u64Prev;
668 if (RT_LIKELY(!(u64Delta >> 32)))
669 {
670 uint64_t u64Sub = ASMMultU64ByU32DivByU32(u64Delta, u32Pct, 100);
671 if (off > u64Sub + offGivenUp)
672 {
673 off -= u64Sub;
674 Log4(("TM: %'RU64/-%'8RU64: sub %RU32 [NoLock]\n", u64 - off, pVM->tm.s.offVirtualSync - offGivenUp, u64Sub));
675 }
676 else
677 {
678 /* we've completely caught up. */
679 STAM_PROFILE_ADV_STOP(&pVM->tm.s.StatVirtualSyncCatchup, c);
680 off = offGivenUp;
681 Log4(("TM: %'RU64/0: caught up [NoLock]\n", u64));
682 }
683 }
684 else
685 /* More than 4 seconds since last time (or negative), ignore it. */
686 Log(("TMVirtualGetSync: u64Delta=%RX64 (NoLock)\n", u64Delta));
687
688 /* Check that we're still running and in catch up. */
689 if ( ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncTicking)
690 && ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
691 break;
692 if (cOuterTries <= 0)
693 break; /* enough */
694 }
695 }
696 else if ( off == ASMAtomicReadU64(&pVM->tm.s.offVirtualSync)
697 && !ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
698 break; /* Got an consistent offset */
699 else if (cOuterTries <= 0)
700 break; /* enough */
701 }
702 if (cOuterTries <= 0)
703 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetELoop);
704
705 /*
706 * Complete the calculation of the current TMCLOCK_VIRTUAL_SYNC time. The current
707 * approach is to never pass the head timer. So, when we do stop the clock and
708 * set the timer pending flag.
709 */
710 u64 -= off;
711 uint64_t u64Expire = ASMAtomicReadU64(&pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL_SYNC].u64Expire);
712 if (u64 >= u64Expire)
713 {
714 PVMCPU pVCpuDst = &pVM->aCpus[pVM->tm.s.idTimerCpu];
715 if (!VMCPU_FF_ISSET(pVCpuDst, VMCPU_FF_TIMER))
716 {
717 Log5(("TMAllVirtual(%u): FF: %d -> 1 (NoLock)\n", __LINE__, VMCPU_FF_ISPENDING(pVCpuDst, VMCPU_FF_TIMER)));
718 VM_FF_SET(pVM, VM_FF_TM_VIRTUAL_SYNC); /* Hmm? */
719 VMCPU_FF_SET(pVCpuDst, VMCPU_FF_TIMER);
720#ifdef IN_RING3
721 REMR3NotifyTimerPending(pVM, pVCpuDst);
722 VMR3NotifyCpuFFU(pVCpuDst->pUVCpu, VMNOTIFYFF_FLAGS_DONE_REM);
723#endif
724 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetSetFF);
725 Log4(("TM: %'RU64/-%'8RU64: exp tmr=>ff [NoLock]\n", u64, pVM->tm.s.offVirtualSync - pVM->tm.s.offVirtualSyncGivenUp));
726 }
727 else
728 Log4(("TM: %'RU64/-%'8RU64: exp tmr [NoLock]\n", u64, pVM->tm.s.offVirtualSync - pVM->tm.s.offVirtualSyncGivenUp));
729 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetExpired);
730 }
731
732 Log6(("tmVirtualSyncGetEx -> %'RU64\n", u64));
733 return u64;
734}
735
736
737/**
738 * Gets the current TMCLOCK_VIRTUAL_SYNC time.
739 *
740 * @returns The timestamp.
741 * @param pVM VM handle.
742 * @thread EMT.
743 * @remarks May set the timer and virtual sync FFs.
744 */
745VMM_INT_DECL(uint64_t) TMVirtualSyncGet(PVM pVM)
746{
747 return tmVirtualSyncGetEx(pVM, true /* check timers */);
748}
749
750
751/**
752 * Gets the current TMCLOCK_VIRTUAL_SYNC time without checking timers running on
753 * TMCLOCK_VIRTUAL.
754 *
755 * @returns The timestamp.
756 * @param pVM VM handle.
757 * @thread EMT.
758 * @remarks May set the timer and virtual sync FFs.
759 */
760VMM_INT_DECL(uint64_t) TMVirtualSyncGetNoCheck(PVM pVM)
761{
762 return tmVirtualSyncGetEx(pVM, false /* check timers */);
763}
764
765
766/**
767 * Gets the current TMCLOCK_VIRTUAL_SYNC time.
768 *
769 * @returns The timestamp.
770 * @param pVM VM handle.
771 * @param fCheckTimers Check timers on the virtual clock or not.
772 * @thread EMT.
773 * @remarks May set the timer and virtual sync FFs.
774 */
775VMM_INT_DECL(uint64_t) TMVirtualSyncGetEx(PVM pVM, bool fCheckTimers)
776{
777 return tmVirtualSyncGetEx(pVM, fCheckTimers);
778}
779
780
781/**
782 * Gets the current lag of the synchronous virtual clock (relative to the virtual clock).
783 *
784 * @return The current lag.
785 * @param pVM VM handle.
786 */
787VMM_INT_DECL(uint64_t) TMVirtualSyncGetLag(PVM pVM)
788{
789 return pVM->tm.s.offVirtualSync - pVM->tm.s.offVirtualSyncGivenUp;
790}
791
792
793/**
794 * Get the current catch-up percent.
795 *
796 * @return The current catch0up percent. 0 means running at the same speed as the virtual clock.
797 * @param pVM VM handle.
798 */
799VMM_INT_DECL(uint32_t) TMVirtualSyncGetCatchUpPct(PVM pVM)
800{
801 if (pVM->tm.s.fVirtualSyncCatchUp)
802 return pVM->tm.s.u32VirtualSyncCatchUpPercentage;
803 return 0;
804}
805
806
807/**
808 * Gets the current TMCLOCK_VIRTUAL frequency.
809 *
810 * @returns The freqency.
811 * @param pVM VM handle.
812 */
813VMM_INT_DECL(uint64_t) TMVirtualGetFreq(PVM pVM)
814{
815 return TMCLOCK_FREQ_VIRTUAL;
816}
817
818
819/**
820 * Worker for TMR3PauseClocks.
821 *
822 * @returns VINF_SUCCESS or VERR_INTERNAL_ERROR (asserted).
823 * @param pVM The VM handle.
824 */
825int tmVirtualPauseLocked(PVM pVM)
826{
827 uint32_t c = ASMAtomicDecU32(&pVM->tm.s.cVirtualTicking);
828 AssertMsgReturn(c < pVM->cCpus, ("%u vs %u\n", c, pVM->cCpus), VERR_INTERNAL_ERROR);
829 if (c == 0)
830 {
831 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualPause);
832 pVM->tm.s.u64Virtual = tmVirtualGetRaw(pVM);
833 ASMAtomicWriteBool(&pVM->tm.s.fVirtualSyncTicking, false);
834 }
835 return VINF_SUCCESS;
836}
837
838
839/**
840 * Worker for TMR3ResumeClocks.
841 *
842 * @returns VINF_SUCCESS or VERR_INTERNAL_ERROR (asserted).
843 * @param pVM The VM handle.
844 */
845int tmVirtualResumeLocked(PVM pVM)
846{
847 uint32_t c = ASMAtomicIncU32(&pVM->tm.s.cVirtualTicking);
848 AssertMsgReturn(c <= pVM->cCpus, ("%u vs %u\n", c, pVM->cCpus), VERR_INTERNAL_ERROR);
849 if (c == 1)
850 {
851 STAM_COUNTER_INC(&pVM->tm.s.StatVirtualResume);
852 pVM->tm.s.u64VirtualRawPrev = 0;
853 pVM->tm.s.u64VirtualWarpDriveStart = tmVirtualGetRawNanoTS(pVM);
854 pVM->tm.s.u64VirtualOffset = pVM->tm.s.u64VirtualWarpDriveStart - pVM->tm.s.u64Virtual;
855 ASMAtomicWriteBool(&pVM->tm.s.fVirtualSyncTicking, true);
856 }
857 return VINF_SUCCESS;
858}
859
860
861/**
862 * Converts from virtual ticks to nanoseconds.
863 *
864 * @returns nanoseconds.
865 * @param pVM The VM handle.
866 * @param u64VirtualTicks The virtual ticks to convert.
867 * @remark There could be rounding errors here. We just do a simple integere divide
868 * without any adjustments.
869 */
870VMM_INT_DECL(uint64_t) TMVirtualToNano(PVM pVM, uint64_t u64VirtualTicks)
871{
872 AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
873 return u64VirtualTicks;
874}
875
876
877/**
878 * Converts from virtual ticks to microseconds.
879 *
880 * @returns microseconds.
881 * @param pVM The VM handle.
882 * @param u64VirtualTicks The virtual ticks to convert.
883 * @remark There could be rounding errors here. We just do a simple integere divide
884 * without any adjustments.
885 */
886VMM_INT_DECL(uint64_t) TMVirtualToMicro(PVM pVM, uint64_t u64VirtualTicks)
887{
888 AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
889 return u64VirtualTicks / 1000;
890}
891
892
893/**
894 * Converts from virtual ticks to milliseconds.
895 *
896 * @returns milliseconds.
897 * @param pVM The VM handle.
898 * @param u64VirtualTicks The virtual ticks to convert.
899 * @remark There could be rounding errors here. We just do a simple integere divide
900 * without any adjustments.
901 */
902VMM_INT_DECL(uint64_t) TMVirtualToMilli(PVM pVM, uint64_t u64VirtualTicks)
903{
904 AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
905 return u64VirtualTicks / 1000000;
906}
907
908
909/**
910 * Converts from nanoseconds to virtual ticks.
911 *
912 * @returns virtual ticks.
913 * @param pVM The VM handle.
914 * @param u64NanoTS The nanosecond value ticks to convert.
915 * @remark There could be rounding and overflow errors here.
916 */
917VMM_INT_DECL(uint64_t) TMVirtualFromNano(PVM pVM, uint64_t u64NanoTS)
918{
919 AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
920 return u64NanoTS;
921}
922
923
924/**
925 * Converts from microseconds to virtual ticks.
926 *
927 * @returns virtual ticks.
928 * @param pVM The VM handle.
929 * @param u64MicroTS The microsecond value ticks to convert.
930 * @remark There could be rounding and overflow errors here.
931 */
932VMM_INT_DECL(uint64_t) TMVirtualFromMicro(PVM pVM, uint64_t u64MicroTS)
933{
934 AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
935 return u64MicroTS * 1000;
936}
937
938
939/**
940 * Converts from milliseconds to virtual ticks.
941 *
942 * @returns virtual ticks.
943 * @param pVM The VM handle.
944 * @param u64MilliTS The millisecond value ticks to convert.
945 * @remark There could be rounding and overflow errors here.
946 */
947VMM_INT_DECL(uint64_t) TMVirtualFromMilli(PVM pVM, uint64_t u64MilliTS)
948{
949 AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
950 return u64MilliTS * 1000000;
951}
952
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