TMAllVirtual.cpp@ 19979

Last change on this file since 19979 was 19810, checked in by vboxsync, 16 years ago
TM: TMTimerPoll hacking.
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1	/* $Id: TMAllVirtual.cpp 19810 2009-05-19 09:59:20Z vboxsync $ */
2	/** @file
3	* TM - Timeout Manager, Virtual Time, All Contexts.
4	*/
5
6	/*
7	* Copyright (C) 2006-2007 Sun Microsystems, Inc.
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	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
18	* Clara, CA 95054 USA or visit http://www.sun.com if you need
19	* additional information or have any questions.
20	*/
21
22
23	/*******************************************************************************
24	* Header Files *
25	*******************************************************************************/
26	#define LOG_GROUP LOG_GROUP_TM
27	#include <VBox/tm.h>
28	#ifdef IN_RING3
29	# include <VBox/rem.h>
30	# include <iprt/thread.h>
31	#endif
32	#include "TMInternal.h"
33	#include <VBox/vm.h>
34	#include <VBox/vmm.h>
35	#include <VBox/err.h>
36	#include <VBox/log.h>
37	#include <VBox/sup.h>
38
39	#include <iprt/time.h>
40	#include <iprt/assert.h>
41	#include <iprt/asm.h>
42
43
44
45	/**
46	* Helper function that's used by the assembly routines when something goes bust.
47	*
48	* @param pData Pointer to the data structure.
49	* @param u64NanoTS The calculated nano ts.
50	* @param u64DeltaPrev The delta relative to the previously returned timestamp.
51	* @param u64PrevNanoTS The previously returned timestamp (as it was read it).
52	*/
53	DECLEXPORT(void) tmVirtualNanoTSBad(PRTTIMENANOTSDATA pData, uint64_t u64NanoTS, uint64_t u64DeltaPrev, uint64_t u64PrevNanoTS)
54	{
55	//PVM pVM = (PVM)((uint8_t *)pData - RT_OFFSETOF(VM, CTXALLSUFF(s.tm.VirtualGetRawData)));
56	pData->cBadPrev++;
57	if ((int64_t)u64DeltaPrev < 0)
58	LogRel(("TM: u64DeltaPrev=%RI64 u64PrevNanoTS=0x%016RX64 u64NanoTS=0x%016RX64\n",
59	u64DeltaPrev, u64PrevNanoTS, u64NanoTS));
60	else
61	Log(("TM: u64DeltaPrev=%RI64 u64PrevNanoTS=0x%016RX64 u64NanoTS=0x%016RX64 (debugging?)\n",
62	u64DeltaPrev, u64PrevNanoTS, u64NanoTS));
63	}
64
65
66	/**
67	* Called the first time somebody asks for the time or when the GIP
68	* is mapped/unmapped.
69	*
70	* This should never ever happen.
71	*/
72	DECLEXPORT(uint64_t) tmVirtualNanoTSRediscover(PRTTIMENANOTSDATA pData)
73	{
74	//PVM pVM = (PVM)((uint8_t *)pData - RT_OFFSETOF(VM, CTXALLSUFF(s.tm.VirtualGetRawData)));
75	PSUPGLOBALINFOPAGE pGip = g_pSUPGlobalInfoPage;
76	AssertFatalMsgFailed(("pGip=%p u32Magic=%#x\n", pGip, VALID_PTR(pGip) ? pGip->u32Magic : 0));
77	}
78
79
80	#if 1
81
82	/**
83	* Wrapper around the IPRT GIP time methods.
84	*/
85	DECLINLINE(uint64_t) tmVirtualGetRawNanoTS(PVM pVM)
86	{
87	#ifdef IN_RING3
88	return CTXALLSUFF(pVM->tm.s.pfnVirtualGetRaw)(&CTXALLSUFF(pVM->tm.s.VirtualGetRawData));
89	# else /* !IN_RING3 */
90	uint32_t cPrevSteps = pVM->tm.s.CTX_SUFF(VirtualGetRawData).c1nsSteps;
91	uint64_t u64 = pVM->tm.s.CTX_SUFF(pfnVirtualGetRaw)(&pVM->tm.s.CTX_SUFF(VirtualGetRawData));
92	if (cPrevSteps != pVM->tm.s.CTX_SUFF(VirtualGetRawData).c1nsSteps)
93	VMCPU_FF_SET(VMMGetCpu(pVM), VMCPU_FF_TO_R3);
94	return u64;
95	# endif /* !IN_RING3 */
96	}
97
98	#else
99
100	/**
101	* This is (mostly) the same as rtTimeNanoTSInternal() except
102	* for the two globals which live in TM.
103	*
104	* @returns Nanosecond timestamp.
105	* @param pVM The VM handle.
106	*/
107	static uint64_t tmVirtualGetRawNanoTS(PVM pVM)
108	{
109	uint64_t u64Delta;
110	uint32_t u32NanoTSFactor0;
111	uint64_t u64TSC;
112	uint64_t u64NanoTS;
113	uint32_t u32UpdateIntervalTSC;
114	uint64_t u64PrevNanoTS;
115
116	/*
117	* Read the GIP data and the previous value.
118	*/
119	for (;;)
120	{
121	uint32_t u32TransactionId;
122	PSUPGLOBALINFOPAGE pGip = g_pSUPGlobalInfoPage;
123	#ifdef IN_RING3
124	if (RT_UNLIKELY(!pGip \|\| pGip->u32Magic != SUPGLOBALINFOPAGE_MAGIC))
125	return RTTimeSystemNanoTS();
126	#endif
127
128	if (pGip->u32Mode != SUPGIPMODE_ASYNC_TSC)
129	{
130	u32TransactionId = pGip->aCPUs[0].u32TransactionId;
131	#ifdef RT_OS_L4
132	Assert((u32TransactionId & 1) == 0);
133	#endif
134	u32UpdateIntervalTSC = pGip->aCPUs[0].u32UpdateIntervalTSC;
135	u64NanoTS = pGip->aCPUs[0].u64NanoTS;
136	u64TSC = pGip->aCPUs[0].u64TSC;
137	u32NanoTSFactor0 = pGip->u32UpdateIntervalNS;
138	u64Delta = ASMReadTSC();
139	u64PrevNanoTS = ASMAtomicReadU64(&pVM->tm.s.u64VirtualRawPrev);
140	if (RT_UNLIKELY( pGip->aCPUs[0].u32TransactionId != u32TransactionId
141	\|\| (u32TransactionId & 1)))
142	continue;
143	}
144	else
145	{
146	/* SUPGIPMODE_ASYNC_TSC */
147	PSUPGIPCPU pGipCpu;
148
149	uint8_t u8ApicId = ASMGetApicId();
150	if (RT_LIKELY(u8ApicId < RT_ELEMENTS(pGip->aCPUs)))
151	pGipCpu = &pGip->aCPUs[u8ApicId];
152	else
153	{
154	AssertMsgFailed(("%x\n", u8ApicId));
155	pGipCpu = &pGip->aCPUs[0];
156	}
157
158	u32TransactionId = pGipCpu->u32TransactionId;
159	#ifdef RT_OS_L4
160	Assert((u32TransactionId & 1) == 0);
161	#endif
162	u32UpdateIntervalTSC = pGipCpu->u32UpdateIntervalTSC;
163	u64NanoTS = pGipCpu->u64NanoTS;
164	u64TSC = pGipCpu->u64TSC;
165	u32NanoTSFactor0 = pGip->u32UpdateIntervalNS;
166	u64Delta = ASMReadTSC();
167	u64PrevNanoTS = ASMAtomicReadU64(&pVM->tm.s.u64VirtualRawPrev);
168	#ifdef IN_RC
169	Assert(!(ASMGetFlags() & X86_EFL_IF));
170	#else
171	if (RT_UNLIKELY(u8ApicId != ASMGetApicId()))
172	continue;
173	if (RT_UNLIKELY( pGipCpu->u32TransactionId != u32TransactionId
174	\|\| (u32TransactionId & 1)))
175	continue;
176	#endif
177	}
178	break;
179	}
180
181	/*
182	* Calc NanoTS delta.
183	*/
184	u64Delta -= u64TSC;
185	if (u64Delta > u32UpdateIntervalTSC)
186	{
187	/*
188	* We've expired the interval, cap it. If we're here for the 2nd
189	* time without any GIP update inbetween, the checks against
190	* pVM->tm.s.u64VirtualRawPrev below will force 1ns stepping.
191	*/
192	u64Delta = u32UpdateIntervalTSC;
193	}
194	#if !defined(_MSC_VER) \|\| defined(RT_ARCH_AMD64) /* GCC makes very pretty code from these two inline calls, while MSC cannot. */
195	u64Delta = ASMMult2xU32RetU64((uint32_t)u64Delta, u32NanoTSFactor0);
196	u64Delta = ASMDivU64ByU32RetU32(u64Delta, u32UpdateIntervalTSC);
197	#else
198	__asm
199	{
200	mov eax, dword ptr [u64Delta]
201	mul dword ptr [u32NanoTSFactor0]
202	div dword ptr [u32UpdateIntervalTSC]
203	mov dword ptr [u64Delta], eax
204	xor edx, edx
205	mov dword ptr [u64Delta + 4], edx
206	}
207	#endif
208
209	/*
210	* Calculate the time and compare it with the previously returned value.
211	*
212	* Since this function is called very frequently when the VM is running
213	* and then mostly on EMT, we can restrict the valid range of the delta
214	* (-1s to 2*GipUpdates) and simplify/optimize the default path.
215	*/
216	u64NanoTS += u64Delta;
217	uint64_t u64DeltaPrev = u64NanoTS - u64PrevNanoTS;
218	if (RT_LIKELY(u64DeltaPrev < 1000000000 /* 1s */))
219	/* frequent - less than 1s since last call. */;
220	else if ( (int64_t)u64DeltaPrev < 0
221	&& (int64_t)u64DeltaPrev + u32NanoTSFactor0 * 2 > 0)
222	{
223	/* occasional - u64NanoTS is in the 'past' relative to previous returns. */
224	ASMAtomicIncU32(&pVM->tm.s.CTX_SUFF(VirtualGetRawData).c1nsSteps);
225	u64NanoTS = u64PrevNanoTS + 1;
226	#ifndef IN_RING3
227	VM_FF_SET(pVM, VM_FF_TO_R3); /* S10 hack */
228	#endif
229	}
230	else if (u64PrevNanoTS)
231	{
232	/* Something has gone bust, if negative offset it's real bad. */
233	ASMAtomicIncU32(&pVM->tm.s.CTX_SUFF(VirtualGetRawData).cBadPrev);
234	if ((int64_t)u64DeltaPrev < 0)
235	LogRel(("TM: u64DeltaPrev=%RI64 u64PrevNanoTS=0x%016RX64 u64NanoTS=0x%016RX64 u64Delta=%#RX64\n",
236	u64DeltaPrev, u64PrevNanoTS, u64NanoTS, u64Delta));
237	else
238	Log(("TM: u64DeltaPrev=%RI64 u64PrevNanoTS=0x%016RX64 u64NanoTS=0x%016RX64 u64Delta=%#RX64 (debugging?)\n",
239	u64DeltaPrev, u64PrevNanoTS, u64NanoTS, u64Delta));
240	#ifdef DEBUG_bird
241	/** @todo there are some hickups during boot and reset that can cause 2-5 seconds delays. Investigate... */
242	AssertMsg(u64PrevNanoTS > UINT64_C(100000000000) /* 100s */,
243	("u64DeltaPrev=%RI64 u64PrevNanoTS=0x%016RX64 u64NanoTS=0x%016RX64 u64Delta=%#RX64\n",
244	u64DeltaPrev, u64PrevNanoTS, u64NanoTS, u64Delta));
245	#endif
246	}
247	/* else: We're resuming (see TMVirtualResume). */
248	if (RT_LIKELY(ASMAtomicCmpXchgU64(&pVM->tm.s.u64VirtualRawPrev, u64NanoTS, u64PrevNanoTS)))
249	return u64NanoTS;
250
251	/*
252	* Attempt updating the previous value, provided we're still ahead of it.
253	*
254	* There is no point in recalculating u64NanoTS because we got preemted or if
255	* we raced somebody while the GIP was updated, since these are events
256	* that might occure at any point in the return path as well.
257	*/
258	for (int cTries = 50;;)
259	{
260	u64PrevNanoTS = ASMAtomicReadU64(&pVM->tm.s.u64VirtualRawPrev);
261	if (u64PrevNanoTS >= u64NanoTS)
262	break;
263	if (ASMAtomicCmpXchgU64(&pVM->tm.s.u64VirtualRawPrev, u64NanoTS, u64PrevNanoTS))
264	break;
265	AssertBreak(--cTries <= 0);
266	if (cTries < 25 && !VM_IS_EMT(pVM)) /* give up early */
267	break;
268	}
269
270	return u64NanoTS;
271	}
272
273	#endif
274
275
276	/**
277	* Get the time when we're not running at 100%
278	*
279	* @returns The timestamp.
280	* @param pVM The VM handle.
281	*/
282	static uint64_t tmVirtualGetRawNonNormal(PVM pVM)
283	{
284	/*
285	* Recalculate the RTTimeNanoTS() value for the period where
286	* warp drive has been enabled.
287	*/
288	uint64_t u64 = tmVirtualGetRawNanoTS(pVM);
289	u64 -= pVM->tm.s.u64VirtualWarpDriveStart;
290	u64 *= pVM->tm.s.u32VirtualWarpDrivePercentage;
291	u64 /= 100;
292	u64 += pVM->tm.s.u64VirtualWarpDriveStart;
293
294	/*
295	* Now we apply the virtual time offset.
296	* (Which is the negated tmVirtualGetRawNanoTS() value for when the virtual
297	* machine started if it had been running continuously without any suspends.)
298	*/
299	u64 -= pVM->tm.s.u64VirtualOffset;
300	return u64;
301	}
302
303
304	/**
305	* Get the raw virtual time.
306	*
307	* @returns The current time stamp.
308	* @param pVM The VM handle.
309	*/
310	DECLINLINE(uint64_t) tmVirtualGetRaw(PVM pVM)
311	{
312	if (RT_LIKELY(!pVM->tm.s.fVirtualWarpDrive))
313	return tmVirtualGetRawNanoTS(pVM) - pVM->tm.s.u64VirtualOffset;
314	return tmVirtualGetRawNonNormal(pVM);
315	}
316
317
318	/**
319	* Inlined version of tmVirtualGetEx.
320	*/
321	DECLINLINE(uint64_t) tmVirtualGet(PVM pVM, bool fCheckTimers)
322	{
323	uint64_t u64;
324	if (RT_LIKELY(pVM->tm.s.cVirtualTicking))
325	{
326	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualGet);
327	u64 = tmVirtualGetRaw(pVM);
328
329	/*
330	* Use the chance to check for expired timers.
331	*/
332	if (fCheckTimers)
333	{
334	PVMCPU pVCpuDst = &pVM->aCpus[pVM->tm.s.idTimerCpu];
335	if ( !VMCPU_FF_ISSET(pVCpuDst, VMCPU_FF_TIMER)
336	&& !pVM->tm.s.fRunningQueues
337	&& ( pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL].u64Expire <= u64
338	\|\| ( pVM->tm.s.fVirtualSyncTicking
339	&& pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL_SYNC].u64Expire <= u64 - pVM->tm.s.offVirtualSync
340	)
341	)
342	&& !pVM->tm.s.fRunningQueues
343	)
344	{
345	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualGetSetFF);
346	Log5(("TMAllVirtual(%u): FF: %d -> 1\n", __LINE__, VMCPU_FF_ISPENDING(pVCpuDst, VMCPU_FF_TIMER)));
347	VMCPU_FF_SET(pVCpuDst, VMCPU_FF_TIMER);
348	#ifdef IN_RING3
349	REMR3NotifyTimerPending(pVM, pVCpuDst);
350	VMR3NotifyCpuFFU(pVCpuDst->pUVCpu, VMNOTIFYFF_FLAGS_DONE_REM);
351	#endif
352	}
353	}
354	}
355	else
356	u64 = pVM->tm.s.u64Virtual;
357	return u64;
358	}
359
360
361	/**
362	* Gets the current TMCLOCK_VIRTUAL time
363	*
364	* @returns The timestamp.
365	* @param pVM VM handle.
366	*
367	* @remark While the flow of time will never go backwards, the speed of the
368	* progress varies due to inaccurate RTTimeNanoTS and TSC. The latter can be
369	* influenced by power saving (SpeedStep, PowerNow!), while the former
370	* makes use of TSC and kernel timers.
371	*/
372	VMMDECL(uint64_t) TMVirtualGet(PVM pVM)
373	{
374	return tmVirtualGet(pVM, true /* check timers */);
375	}
376
377
378	/**
379	* Gets the current TMCLOCK_VIRTUAL time without checking
380	* timers or anything.
381	*
382	* Meaning, this has no side effect on FFs like TMVirtualGet may have.
383	*
384	* @returns The timestamp.
385	* @param pVM VM handle.
386	*
387	* @remarks See TMVirtualGet.
388	*/
389	VMMDECL(uint64_t) TMVirtualGetNoCheck(PVM pVM)
390	{
391	return tmVirtualGet(pVM, false /fCheckTimers/);
392	}
393
394
395	/**
396	* tmVirtualSyncGetLocked worker for handling catch-up when owning the lock.
397	*
398	* @returns The timestamp.
399	* @param pVM VM handle.
400	* @param u64 raw virtual time.
401	* @param off offVirtualSync.
402	*/
403	DECLINLINE(uint64_t) tmVirtualSyncGetHandleCatchUpLocked(PVM pVM, uint64_t u64, uint64_t off)
404	{
405	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLocked);
406
407	/*
408	* Don't make updates untill
409	*/
410	bool fUpdatePrev = true;
411	bool fUpdateOff = true;
412	bool fStop = false;
413	const uint64_t u64Prev = pVM->tm.s.u64VirtualSyncCatchUpPrev;
414	uint64_t u64Delta = u64 - u64Prev;
415	if (RT_LIKELY(!(u64Delta >> 32)))
416	{
417	uint64_t u64Sub = ASMMultU64ByU32DivByU32(u64Delta, pVM->tm.s.u32VirtualSyncCatchUpPercentage, 100);
418	if (off > u64Sub + pVM->tm.s.offVirtualSyncGivenUp)
419	{
420	off -= u64Sub;
421	Log4(("TM: %RU64/%RU64: sub %RU32\n", u64 - off, off - pVM->tm.s.offVirtualSyncGivenUp, u64Sub));
422	}
423	else
424	{
425	/* we've completely caught up. */
426	STAM_PROFILE_ADV_STOP(&pVM->tm.s.StatVirtualSyncCatchup, c);
427	off = pVM->tm.s.offVirtualSyncGivenUp;
428	fStop = true;
429	Log4(("TM: %RU64/0: caught up\n", u64));
430	}
431	}
432	else
433	{
434	/* More than 4 seconds since last time (or negative), ignore it. */
435	fUpdateOff = false;
436	fUpdatePrev = !(u64Delta & RT_BIT_64(63));
437	Log(("TMVirtualGetSync: u64Delta=%RX64\n", u64Delta));
438	}
439
440	/*
441	* Complete the calculation of the current TMCLOCK_VIRTUAL_SYNC time. The current
442	* approach is to never pass the head timer. So, when we do stop the clock and
443	* set the timer pending flag.
444	*/
445	u64 -= off;
446	uint64_t u64Expire = ASMAtomicReadU64(&pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL_SYNC].u64Expire);
447	if (u64 < u64Expire)
448	{
449	if (fUpdateOff)
450	ASMAtomicWriteU64(&pVM->tm.s.offVirtualSync, off);
451	if (fStop)
452	ASMAtomicWriteBool(&pVM->tm.s.fVirtualSyncCatchUp, false);
453	if (fUpdatePrev)
454	ASMAtomicWriteU64(&pVM->tm.s.u64VirtualSyncCatchUpPrev, u64);
455	tmVirtualSyncUnlock(pVM);
456	}
457	else
458	{
459	u64 = u64Expire;
460	ASMAtomicWriteU64(&pVM->tm.s.u64VirtualSync, u64);
461	ASMAtomicWriteBool(&pVM->tm.s.fVirtualSyncTicking, false);
462
463	VM_FF_SET(pVM, VM_FF_TM_VIRTUAL_SYNC);
464	PVMCPU pVCpuDst = &pVM->aCpus[pVM->tm.s.idTimerCpu];
465	VMCPU_FF_SET(pVCpuDst, VMCPU_FF_TIMER);
466	Log5(("TMAllVirtual(%u): FF: %d -> 1\n", __LINE__, VMCPU_FF_ISPENDING(pVCpuDst, VMCPU_FF_TIMER)));
467	Log4(("TM: %RU64/%RU64: exp tmr=>ff\n", u64, pVM->tm.s.offVirtualSync - pVM->tm.s.offVirtualSyncGivenUp));
468	tmVirtualSyncUnlock(pVM);
469
470	#ifdef IN_RING3
471	REMR3NotifyTimerPending(pVM, pVCpuDst);
472	VMR3NotifyCpuFFU(pVCpuDst->pUVCpu, VMNOTIFYFF_FLAGS_DONE_REM);
473	#endif
474	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetSetFF);
475	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetExpired);
476	}
477	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLocked);
478
479	return u64;
480	}
481
482
483	/**
484	* tmVirtualSyncGetEx worker for when we get the lock.
485	*
486	* @returns timesamp.
487	* @param pVM The VM handle.
488	* @param u64 The virtual clock timestamp.
489	*/
490	DECLINLINE(uint64_t) tmVirtualSyncGetLocked(PVM pVM, uint64_t u64)
491	{
492	/*
493	* Not ticking?
494	*/
495	if (!pVM->tm.s.fVirtualSyncTicking)
496	{
497	u64 = ASMAtomicUoReadU64(&pVM->tm.s.u64VirtualSync);
498	tmVirtualSyncUnlock(pVM);
499	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLocked);
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/%RU64: exp tmr=>ff\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	return u64;
541	}
542
543
544	/**
545	* Gets the current TMCLOCK_VIRTUAL_SYNC time.
546	*
547	* @returns The timestamp.
548	* @param pVM VM handle.
549	* @param fCheckTimers Check timers or not
550	* @thread EMT.
551	*/
552	DECLINLINE(uint64_t) tmVirtualSyncGetEx(PVM pVM, bool fCheckTimers)
553	{
554	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGet);
555
556	if (!pVM->tm.s.fVirtualSyncTicking)
557	return pVM->tm.s.u64VirtualSync;
558
559	/*
560	* Query the virtual clock and do the usual expired timer check.
561	*/
562	Assert(pVM->tm.s.cVirtualTicking);
563	uint64_t u64 = tmVirtualGetRaw(pVM);
564	if (fCheckTimers)
565	{
566	PVMCPU pVCpuDst = &pVM->aCpus[pVM->tm.s.idTimerCpu];
567	if ( !VMCPU_FF_ISSET(pVCpuDst, VMCPU_FF_TIMER)
568	&& pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL].u64Expire <= u64)
569	{
570	Log5(("TMAllVirtual(%u): FF: 0 -> 1\n", __LINE__));
571	VMCPU_FF_SET(pVCpuDst, VMCPU_FF_TIMER);
572	#ifdef IN_RING3
573	REMR3NotifyTimerPending(pVM, pVCpuDst);
574	VMR3NotifyCpuFFU(pVCpuDst->pUVCpu, VMNOTIFYFF_FLAGS_DONE_REM /** @todo \|VMNOTIFYFF_FLAGS_POKE*/);
575	#endif
576	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetSetFF);
577	}
578	}
579
580	/*
581	* When the clock is ticking, not doing catch ups and not running into an
582	* expired time, we can get away without locking. Try this first.
583	*/
584	uint64_t off;
585	if (ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncTicking))
586	{
587	if (!ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
588	{
589	off = ASMAtomicReadU64(&pVM->tm.s.offVirtualSync);
590	if (RT_LIKELY( ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncTicking)
591	&& !ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncCatchUp)
592	&& off == ASMAtomicReadU64(&pVM->tm.s.offVirtualSync)))
593	{
594	off = u64 - off;
595	if (off < ASMAtomicReadU64(&pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL_SYNC].u64Expire))
596	{
597	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLockless);
598	return off;
599	}
600	}
601	}
602	}
603	else
604	{
605	off = ASMAtomicReadU64(&pVM->tm.s.u64VirtualSync);
606	if (RT_LIKELY(!ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncTicking)))
607	{
608	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetLockless);
609	return off;
610	}
611	}
612
613	/*
614	* Read the offset and adjust if we're playing catch-up.
615	*
616	* The catch-up adjusting work by us decrementing the offset by a percentage of
617	* the time elapsed since the previous TMVirtualGetSync call.
618	*
619	* It's possible to get a very long or even negative interval between two read
620	* for the following reasons:
621	* - Someone might have suspended the process execution, frequently the case when
622	* debugging the process.
623	* - We might be on a different CPU which TSC isn't quite in sync with the
624	* other CPUs in the system.
625	* - Another thread is racing us and we might have been preemnted while inside
626	* this function.
627	*
628	* Assuming nano second virtual time, we can simply ignore any intervals which has
629	* any of the upper 32 bits set.
630	*/
631	AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
632	int cOuterTries = 42;
633	for (;; cOuterTries--)
634	{
635	/* Try grab the lock, things get simpler when owning the lock. */
636	int rcLock = tmVirtualSyncTryLock(pVM);
637	if (RT_SUCCESS_NP(rcLock))
638	return tmVirtualSyncGetLocked(pVM, u64);
639
640	/* Re-check the ticking flag. */
641	if (!ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncTicking))
642	{
643	off = ASMAtomicReadU64(&pVM->tm.s.u64VirtualSync);
644	if ( ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncTicking)
645	&& cOuterTries > 0)
646	continue;
647	return off;
648	}
649
650	off = ASMAtomicReadU64(&pVM->tm.s.offVirtualSync);
651	if (ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
652	{
653	/* No changes allowed, try get a consistent set of parameters. */
654	uint64_t const u64Prev = ASMAtomicReadU64(&pVM->tm.s.u64VirtualSyncCatchUpPrev);
655	uint64_t const offGivenUp = ASMAtomicReadU64(&pVM->tm.s.offVirtualSyncGivenUp);
656	uint32_t const u32Pct = ASMAtomicReadU32(&pVM->tm.s.u32VirtualSyncCatchUpPercentage);
657	if ( ( u64Prev == ASMAtomicReadU64(&pVM->tm.s.u64VirtualSyncCatchUpPrev)
658	&& offGivenUp == ASMAtomicReadU64(&pVM->tm.s.offVirtualSyncGivenUp)
659	&& u32Pct == ASMAtomicReadU32(&pVM->tm.s.u32VirtualSyncCatchUpPercentage)
660	&& ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
661	\|\| cOuterTries <= 0)
662	{
663	uint64_t u64Delta = u64 - u64Prev;
664	if (RT_LIKELY(!(u64Delta >> 32)))
665	{
666	uint64_t u64Sub = ASMMultU64ByU32DivByU32(u64Delta, u32Pct, 100);
667	if (off > u64Sub + offGivenUp)
668	{
669	off -= u64Sub;
670	Log4(("TM: %RU64/%RU64: sub %RU32 (NoLock)\n", u64 - off, pVM->tm.s.offVirtualSync - offGivenUp, u64Sub));
671	}
672	else
673	{
674	/* we've completely caught up. */
675	STAM_PROFILE_ADV_STOP(&pVM->tm.s.StatVirtualSyncCatchup, c);
676	off = offGivenUp;
677	Log4(("TM: %RU64/0: caught up\n", u64));
678	}
679	}
680	else
681	/* More than 4 seconds since last time (or negative), ignore it. */
682	Log(("TMVirtualGetSync: u64Delta=%RX64 (NoLock)\n", u64Delta));
683
684	/* Check that we're still running and in catch up. */
685	if ( ASMAtomicUoReadBool(&pVM->tm.s.fVirtualSyncTicking)
686	&& ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
687	break;
688	if (cOuterTries <= 0)
689	break; /* enough */
690	}
691	}
692	else if ( off == ASMAtomicReadU64(&pVM->tm.s.offVirtualSync)
693	&& !ASMAtomicReadBool(&pVM->tm.s.fVirtualSyncCatchUp))
694	break; /* Got an consistent offset */
695	else if (cOuterTries <= 0)
696	break; /* enough */
697	}
698	if (cOuterTries <= 0)
699	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetELoop);
700
701	/*
702	* Complete the calculation of the current TMCLOCK_VIRTUAL_SYNC time. The current
703	* approach is to never pass the head timer. So, when we do stop the clock and
704	* set the timer pending flag.
705	*/
706	u64 -= off;
707	uint64_t u64Expire = ASMAtomicReadU64(&pVM->tm.s.CTX_SUFF(paTimerQueues)[TMCLOCK_VIRTUAL_SYNC].u64Expire);
708	if (u64 >= u64Expire)
709	{
710	PVMCPU pVCpuDst = &pVM->aCpus[pVM->tm.s.idTimerCpu];
711	if (!VMCPU_FF_ISSET(pVCpuDst, VMCPU_FF_TIMER))
712	{
713	Log5(("TMAllVirtual(%u): FF: %d -> 1 (NoLock)\n", __LINE__, VMCPU_FF_ISPENDING(pVCpuDst, VMCPU_FF_TIMER)));
714	VM_FF_SET(pVM, VM_FF_TM_VIRTUAL_SYNC); /* Hmm? */
715	VMCPU_FF_SET(pVCpuDst, VMCPU_FF_TIMER);
716	#ifdef IN_RING3
717	REMR3NotifyTimerPending(pVM, pVCpuDst);
718	VMR3NotifyCpuFFU(pVCpuDst->pUVCpu, VMNOTIFYFF_FLAGS_DONE_REM);
719	#endif
720	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetSetFF);
721	Log4(("TM: %RU64/%RU64: exp tmr=>ff (NoLock)\n", u64, pVM->tm.s.offVirtualSync - pVM->tm.s.offVirtualSyncGivenUp));
722	}
723	else
724	Log4(("TM: %RU64/%RU64: exp tmr (NoLock)\n", u64, pVM->tm.s.offVirtualSync - pVM->tm.s.offVirtualSyncGivenUp));
725	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualSyncGetExpired);
726	}
727
728	return u64;
729	}
730
731
732	/**
733	* Gets the current TMCLOCK_VIRTUAL_SYNC time.
734	*
735	* @returns The timestamp.
736	* @param pVM VM handle.
737	* @thread EMT.
738	* @remarks May set the timer and virtual sync FFs.
739	*/
740	VMMDECL(uint64_t) TMVirtualSyncGet(PVM pVM)
741	{
742	return tmVirtualSyncGetEx(pVM, true /* check timers */);
743	}
744
745
746	/**
747	* Gets the current TMCLOCK_VIRTUAL_SYNC time without checking timers running on
748	* TMCLOCK_VIRTUAL.
749	*
750	* @returns The timestamp.
751	* @param pVM VM handle.
752	* @thread EMT.
753	* @remarks May set the timer and virtual sync FFs.
754	*/
755	VMMDECL(uint64_t) TMVirtualSyncGetNoCheck(PVM pVM)
756	{
757	return tmVirtualSyncGetEx(pVM, false /* check timers */);
758	}
759
760
761	/**
762	* Gets the current TMCLOCK_VIRTUAL_SYNC time.
763	*
764	* @returns The timestamp.
765	* @param pVM VM handle.
766	* @param fCheckTimers Check timers on the virtual clock or not.
767	* @thread EMT.
768	* @remarks May set the timer and virtual sync FFs.
769	*/
770	VMMDECL(uint64_t) TMVirtualSyncGetEx(PVM pVM, bool fCheckTimers)
771	{
772	return tmVirtualSyncGetEx(pVM, fCheckTimers);
773	}
774
775
776	/**
777	* Gets the current lag of the synchronous virtual clock (relative to the virtual clock).
778	*
779	* @return The current lag.
780	* @param pVM VM handle.
781	*/
782	VMMDECL(uint64_t) TMVirtualSyncGetLag(PVM pVM)
783	{
784	return pVM->tm.s.offVirtualSync - pVM->tm.s.offVirtualSyncGivenUp;
785	}
786
787
788	/**
789	* Get the current catch-up percent.
790	*
791	* @return The current catch0up percent. 0 means running at the same speed as the virtual clock.
792	* @param pVM VM handle.
793	*/
794	VMMDECL(uint32_t) TMVirtualSyncGetCatchUpPct(PVM pVM)
795	{
796	if (pVM->tm.s.fVirtualSyncCatchUp)
797	return pVM->tm.s.u32VirtualSyncCatchUpPercentage;
798	return 0;
799	}
800
801
802	/**
803	* Gets the current TMCLOCK_VIRTUAL frequency.
804	*
805	* @returns The freqency.
806	* @param pVM VM handle.
807	*/
808	VMMDECL(uint64_t) TMVirtualGetFreq(PVM pVM)
809	{
810	return TMCLOCK_FREQ_VIRTUAL;
811	}
812
813
814	/**
815	* Worker for TMR3PauseClocks.
816	*
817	* @returns VINF_SUCCESS or VERR_INTERNAL_ERROR (asserted).
818	* @param pVM The VM handle.
819	*/
820	int tmVirtualPauseLocked(PVM pVM)
821	{
822	uint32_t c = ASMAtomicDecU32(&pVM->tm.s.cVirtualTicking);
823	AssertMsgReturn(c < pVM->cCPUs, ("%u vs %u\n", c, pVM->cCPUs), VERR_INTERNAL_ERROR);
824	if (c == 0)
825	{
826	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualPause);
827	pVM->tm.s.u64Virtual = tmVirtualGetRaw(pVM);
828	ASMAtomicWriteBool(&pVM->tm.s.fVirtualSyncTicking, false);
829	}
830	return VINF_SUCCESS;
831	}
832
833
834	/**
835	* Worker for TMR3ResumeClocks.
836	*
837	* @returns VINF_SUCCESS or VERR_INTERNAL_ERROR (asserted).
838	* @param pVM The VM handle.
839	*/
840	int tmVirtualResumeLocked(PVM pVM)
841	{
842	uint32_t c = ASMAtomicIncU32(&pVM->tm.s.cVirtualTicking);
843	AssertMsgReturn(c <= pVM->cCPUs, ("%u vs %u\n", c, pVM->cCPUs), VERR_INTERNAL_ERROR);
844	if (c == 1)
845	{
846	STAM_COUNTER_INC(&pVM->tm.s.StatVirtualResume);
847	pVM->tm.s.u64VirtualRawPrev = 0;
848	pVM->tm.s.u64VirtualWarpDriveStart = tmVirtualGetRawNanoTS(pVM);
849	pVM->tm.s.u64VirtualOffset = pVM->tm.s.u64VirtualWarpDriveStart - pVM->tm.s.u64Virtual;
850	ASMAtomicWriteBool(&pVM->tm.s.fVirtualSyncTicking, true);
851	}
852	return VINF_SUCCESS;
853	}
854
855
856	/**
857	* Converts from virtual ticks to nanoseconds.
858	*
859	* @returns nanoseconds.
860	* @param pVM The VM handle.
861	* @param u64VirtualTicks The virtual ticks to convert.
862	* @remark There could be rounding errors here. We just do a simple integere divide
863	* without any adjustments.
864	*/
865	VMMDECL(uint64_t) TMVirtualToNano(PVM pVM, uint64_t u64VirtualTicks)
866	{
867	AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
868	return u64VirtualTicks;
869	}
870
871
872	/**
873	* Converts from virtual ticks to microseconds.
874	*
875	* @returns microseconds.
876	* @param pVM The VM handle.
877	* @param u64VirtualTicks The virtual ticks to convert.
878	* @remark There could be rounding errors here. We just do a simple integere divide
879	* without any adjustments.
880	*/
881	VMMDECL(uint64_t) TMVirtualToMicro(PVM pVM, uint64_t u64VirtualTicks)
882	{
883	AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
884	return u64VirtualTicks / 1000;
885	}
886
887
888	/**
889	* Converts from virtual ticks to milliseconds.
890	*
891	* @returns milliseconds.
892	* @param pVM The VM handle.
893	* @param u64VirtualTicks The virtual ticks to convert.
894	* @remark There could be rounding errors here. We just do a simple integere divide
895	* without any adjustments.
896	*/
897	VMMDECL(uint64_t) TMVirtualToMilli(PVM pVM, uint64_t u64VirtualTicks)
898	{
899	AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
900	return u64VirtualTicks / 1000000;
901	}
902
903
904	/**
905	* Converts from nanoseconds to virtual ticks.
906	*
907	* @returns virtual ticks.
908	* @param pVM The VM handle.
909	* @param u64NanoTS The nanosecond value ticks to convert.
910	* @remark There could be rounding and overflow errors here.
911	*/
912	VMMDECL(uint64_t) TMVirtualFromNano(PVM pVM, uint64_t u64NanoTS)
913	{
914	AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
915	return u64NanoTS;
916	}
917
918
919	/**
920	* Converts from microseconds to virtual ticks.
921	*
922	* @returns virtual ticks.
923	* @param pVM The VM handle.
924	* @param u64MicroTS The microsecond value ticks to convert.
925	* @remark There could be rounding and overflow errors here.
926	*/
927	VMMDECL(uint64_t) TMVirtualFromMicro(PVM pVM, uint64_t u64MicroTS)
928	{
929	AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
930	return u64MicroTS * 1000;
931	}
932
933
934	/**
935	* Converts from milliseconds to virtual ticks.
936	*
937	* @returns virtual ticks.
938	* @param pVM The VM handle.
939	* @param u64MilliTS The millisecond value ticks to convert.
940	* @remark There could be rounding and overflow errors here.
941	*/
942	VMMDECL(uint64_t) TMVirtualFromMilli(PVM pVM, uint64_t u64MilliTS)
943	{
944	AssertCompile(TMCLOCK_FREQ_VIRTUAL == 1000000000);
945	return u64MilliTS * 1000000;
946	}
947

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source: vbox/trunk/src/VBox/VMM/VMMAll/TMAllVirtual.cpp@ 19979

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