VirtualBox

source: vbox/trunk/src/VBox/VMM/VMMAll/TMAllCpu.cpp@ 19454

Last change on this file since 19454 was 19032, checked in by vboxsync, 16 years ago

Split TM for SMP guests.
  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
File size: 8.3 KB
Line 
1/* $Id: TMAllCpu.cpp 19032 2009-04-20 15:03:08Z vboxsync $ */
2/** @file
3 * TM - Timeout Manager, CPU 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#include "../TMInternal.h"
29#include <VBox/vm.h>
30#include <VBox/sup.h>
31
32#include <VBox/param.h>
33#include <VBox/err.h>
34#include <iprt/assert.h>
35#include <iprt/asm.h>
36#include <VBox/log.h>
37
38
39/**
40 * Gets the raw cpu tick from current virtual time.
41 */
42DECLINLINE(uint64_t) tmCpuTickGetRawVirtual(PVM pVM, bool fCheckTimers)
43{
44 uint64_t u64 = TMVirtualSyncGetEx(pVM, fCheckTimers);
45 if (u64 != TMCLOCK_FREQ_VIRTUAL)
46 u64 = ASMMultU64ByU32DivByU32(u64, pVM->tm.s.cTSCTicksPerSecond, TMCLOCK_FREQ_VIRTUAL);
47 return u64;
48}
49
50
51/**
52 * Resumes the CPU timestamp counter ticking.
53 *
54 * @returns VBox status code.
55 * @param pVM The VM to operate on.
56 * @param pVCpu The VMCPU to operate on.
57 * @internal
58 */
59int tmCpuTickResume(PVM pVM, PVMCPU pVCpu)
60{
61 if (!pVCpu->tm.s.fTSCTicking)
62 {
63 pVCpu->tm.s.fTSCTicking = true;
64 if (pVM->tm.s.fTSCVirtualized)
65 {
66 if (pVM->tm.s.fTSCUseRealTSC)
67 pVCpu->tm.s.u64TSCOffset = ASMReadTSC() - pVCpu->tm.s.u64TSC;
68 else
69 pVCpu->tm.s.u64TSCOffset = tmCpuTickGetRawVirtual(pVM, false /* don't check for pending timers */)
70 - pVCpu->tm.s.u64TSC;
71 }
72 return VINF_SUCCESS;
73 }
74 AssertFailed();
75 return VERR_INTERNAL_ERROR;
76}
77
78
79/**
80 * Resumes the CPU timestamp counter ticking.
81 *
82 * @returns VBox status code.
83 * @param pVCpu The VMCPU to operate on.
84 * @todo replace this with TMNotifyResume
85 */
86VMMDECL(int) TMCpuTickResume(PVMCPU pVCpu)
87{
88 PVM pVM = pVCpu->CTX_SUFF(pVM);
89
90 if (!pVM->tm.s.fTSCTiedToExecution)
91 return tmCpuTickResume(pVM, pVCpu);
92 /* ignored */
93 return VINF_SUCCESS;
94}
95
96
97/**
98 * Pauses the CPU timestamp counter ticking.
99 *
100 * @returns VBox status code.
101 * @param pVM The VM to operate on.
102 * @param pVCpu The VMCPU to operate on.
103 * @internal
104 */
105int tmCpuTickPause(PVM pVM, PVMCPU pVCpu)
106{
107 if (pVCpu->tm.s.fTSCTicking)
108 {
109 pVCpu->tm.s.u64TSC = TMCpuTickGet(pVCpu);
110 pVCpu->tm.s.fTSCTicking = false;
111 return VINF_SUCCESS;
112 }
113 AssertFailed();
114 return VERR_INTERNAL_ERROR;
115}
116
117
118/**
119 * Pauses the CPU timestamp counter ticking.
120 *
121 * @returns VBox status code.
122 * @param pVCpu The VMCPU to operate on.
123 * @todo replace this with TMNotifySuspend
124 */
125VMMDECL(int) TMCpuTickPause(PVMCPU pVCpu)
126{
127 PVM pVM = pVCpu->CTX_SUFF(pVM);
128
129 if (!pVM->tm.s.fTSCTiedToExecution)
130 return tmCpuTickPause(pVM, pVCpu);
131 /* ignored */
132 return VINF_SUCCESS;
133}
134
135
136/**
137 * Checks if AMD-V / VT-x can use an offsetted hardware TSC or not.
138 *
139 * @returns true/false accordingly.
140 * @param pVCpu The VMCPU to operate on.
141 * @param poffRealTSC The offset against the TSC of the current CPU.
142 * Can be NULL.
143 * @thread EMT.
144 */
145VMMDECL(bool) TMCpuTickCanUseRealTSC(PVMCPU pVCpu, uint64_t *poffRealTSC)
146{
147 PVM pVM = pVCpu->CTX_SUFF(pVM);
148
149 /*
150 * We require:
151 * 1. A fixed TSC, this is checked at init time.
152 * 2. That the TSC is ticking (we shouldn't be here if it isn't)
153 * 3. Either that we're using the real TSC as time source or
154 * a) we don't have any lag to catch up, and
155 * b) the virtual sync clock hasn't been halted by an expired timer, and
156 * c) we're not using warp drive (accelerated virtual guest time).
157 */
158 if ( pVM->tm.s.fMaybeUseOffsettedHostTSC
159 && RT_LIKELY(pVCpu->tm.s.fTSCTicking)
160 && ( pVM->tm.s.fTSCUseRealTSC
161 || ( !pVM->tm.s.fVirtualSyncCatchUp
162 && RT_LIKELY(pVM->tm.s.fVirtualSyncTicking)
163 && !pVM->tm.s.fVirtualWarpDrive))
164 )
165 {
166 if (!pVM->tm.s.fTSCUseRealTSC)
167 {
168 /* The source is the timer synchronous virtual clock. */
169 Assert(pVM->tm.s.fTSCVirtualized);
170
171 if (poffRealTSC)
172 {
173 uint64_t u64Now = tmCpuTickGetRawVirtual(pVM, false /* don't check for pending timers */)
174 - pVCpu->tm.s.u64TSCOffset;
175 /** @todo When we start collecting statistics on how much time we spend executing
176 * guest code before exiting, we should check this against the next virtual sync
177 * timer timeout. If it's lower than the avg. length, we should trap rdtsc to increase
178 * the chance that we'll get interrupted right after the timer expired. */
179 *poffRealTSC = u64Now - ASMReadTSC();
180 }
181 }
182 else if (poffRealTSC)
183 {
184 /* The source is the real TSC. */
185 if (pVM->tm.s.fTSCVirtualized)
186 *poffRealTSC = pVCpu->tm.s.u64TSCOffset;
187 else
188 *poffRealTSC = 0;
189 }
190 /** @todo count this? */
191 return true;
192 }
193
194#ifdef VBOX_WITH_STATISTICS
195 /* Sample the reason for refusing. */
196 if (!pVM->tm.s.fMaybeUseOffsettedHostTSC)
197 STAM_COUNTER_INC(&pVM->tm.s.StatTSCNotFixed);
198 else if (!pVCpu->tm.s.fTSCTicking)
199 STAM_COUNTER_INC(&pVM->tm.s.StatTSCNotTicking);
200 else if (!pVM->tm.s.fTSCUseRealTSC)
201 {
202 if (pVM->tm.s.fVirtualSyncCatchUp)
203 {
204 if (pVM->tm.s.u32VirtualSyncCatchUpPercentage <= 10)
205 STAM_COUNTER_INC(&pVM->tm.s.StatTSCCatchupLE010);
206 else if (pVM->tm.s.u32VirtualSyncCatchUpPercentage <= 25)
207 STAM_COUNTER_INC(&pVM->tm.s.StatTSCCatchupLE025);
208 else if (pVM->tm.s.u32VirtualSyncCatchUpPercentage <= 100)
209 STAM_COUNTER_INC(&pVM->tm.s.StatTSCCatchupLE100);
210 else
211 STAM_COUNTER_INC(&pVM->tm.s.StatTSCCatchupOther);
212 }
213 else if (!pVM->tm.s.fVirtualSyncTicking)
214 STAM_COUNTER_INC(&pVM->tm.s.StatTSCSyncNotTicking);
215 else if (pVM->tm.s.fVirtualWarpDrive)
216 STAM_COUNTER_INC(&pVM->tm.s.StatTSCWarp);
217 }
218#endif
219 return false;
220}
221
222
223/**
224 * Read the current CPU timstamp counter.
225 *
226 * @returns Gets the CPU tsc.
227 * @param pVCpu The VMCPU to operate on.
228 */
229VMMDECL(uint64_t) TMCpuTickGet(PVMCPU pVCpu)
230{
231 PVM pVM = pVCpu->CTX_SUFF(pVM);
232 uint64_t u64;
233
234 if (RT_LIKELY(pVCpu->tm.s.fTSCTicking))
235 {
236 if (pVM->tm.s.fTSCVirtualized)
237 {
238 if (pVM->tm.s.fTSCUseRealTSC)
239 u64 = ASMReadTSC();
240 else
241 u64 = tmCpuTickGetRawVirtual(pVM, true /* check for pending timers */);
242 u64 -= pVCpu->tm.s.u64TSCOffset;
243 }
244 else
245 u64 = ASMReadTSC();
246 }
247 else
248 u64 = pVCpu->tm.s.u64TSC;
249 return u64;
250}
251
252
253/**
254 * Sets the current CPU timestamp counter.
255 *
256 * @returns VBox status code.
257 * @param pVCpu The VMCPU to operate on.
258 * @param u64Tick The new timestamp value.
259 */
260VMMDECL(int) TMCpuTickSet(PVMCPU pVCpu, uint64_t u64Tick)
261{
262 Assert(!pVCpu->tm.s.fTSCTicking);
263 pVCpu->tm.s.u64TSC = u64Tick;
264 return VINF_SUCCESS;
265}
266
267
268/**
269 * Get the timestamp frequency.
270 *
271 * @returns Number of ticks per second.
272 * @param pVM The VM.
273 */
274VMMDECL(uint64_t) TMCpuTicksPerSecond(PVM pVM)
275{
276 if (pVM->tm.s.fTSCUseRealTSC)
277 {
278 uint64_t cTSCTicksPerSecond = SUPGetCpuHzFromGIP(g_pSUPGlobalInfoPage);
279 if (RT_LIKELY(cTSCTicksPerSecond != ~(uint64_t)0))
280 return cTSCTicksPerSecond;
281 }
282 return pVM->tm.s.cTSCTicksPerSecond;
283}
284
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