VirtualBox

source: vbox/trunk/src/VBox/HostDrivers/Support/SUPLibAll.cpp@ 76553

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1/* $Id: SUPLibAll.cpp 76553 2019-01-01 01:45:53Z vboxsync $ */
2/** @file
3 * VirtualBox Support Library - All Contexts Code.
4 */
5
6/*
7 * Copyright (C) 2006-2019 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 * The contents of this file may alternatively be used under the terms
18 * of the Common Development and Distribution License Version 1.0
19 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20 * VirtualBox OSE distribution, in which case the provisions of the
21 * CDDL are applicable instead of those of the GPL.
22 *
23 * You may elect to license modified versions of this file under the
24 * terms and conditions of either the GPL or the CDDL or both.
25 */
26
27
28/*********************************************************************************************************************************
29* Header Files *
30*********************************************************************************************************************************/
31#include <VBox/sup.h>
32#ifdef IN_RC
33# include <VBox/vmm/vm.h>
34# include <VBox/vmm/vmm.h>
35#endif
36#ifdef IN_RING0
37# include <iprt/mp.h>
38#endif
39#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
40# include <iprt/asm-amd64-x86.h>
41#endif
42#include <iprt/errcore.h>
43
44
45#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
46
47/**
48 * The slow case for SUPReadTsc where we need to apply deltas.
49 *
50 * Must only be called when deltas are applicable, so please do not call it
51 * directly.
52 *
53 * @returns TSC with delta applied.
54 * @param pGip Pointer to the GIP.
55 *
56 * @remarks May be called with interrupts disabled in ring-0! This is why the
57 * ring-0 code doesn't attempt to figure the delta.
58 *
59 * @internal
60 */
61SUPDECL(uint64_t) SUPReadTscWithDelta(PSUPGLOBALINFOPAGE pGip)
62{
63 uint64_t uTsc;
64 uint16_t iGipCpu;
65 AssertCompile(RT_IS_POWER_OF_TWO(RTCPUSET_MAX_CPUS));
66 AssertCompile(RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx) >= RTCPUSET_MAX_CPUS);
67 Assert(pGip->enmUseTscDelta > SUPGIPUSETSCDELTA_PRACTICALLY_ZERO);
68
69 /*
70 * Read the TSC and get the corresponding aCPUs index.
71 */
72#ifdef IN_RING3
73 if (pGip->fGetGipCpu & SUPGIPGETCPU_RDTSCP_MASK_MAX_SET_CPUS)
74 {
75 /* RDTSCP gives us all we need, no loops/cli. */
76 uint32_t iCpuSet;
77 uTsc = ASMReadTscWithAux(&iCpuSet);
78 iCpuSet &= RTCPUSET_MAX_CPUS - 1;
79 iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet];
80 }
81 else if (pGip->fGetGipCpu & SUPGIPGETCPU_IDTR_LIMIT_MASK_MAX_SET_CPUS)
82 {
83 /* Storing the IDTR is normally very quick, but we need to loop. */
84 uint32_t cTries = 0;
85 for (;;)
86 {
87 uint16_t cbLim = ASMGetIdtrLimit();
88 uTsc = ASMReadTSC();
89 if (RT_LIKELY(ASMGetIdtrLimit() == cbLim))
90 {
91 uint16_t iCpuSet = cbLim - 256 * (ARCH_BITS == 64 ? 16 : 8);
92 iCpuSet &= RTCPUSET_MAX_CPUS - 1;
93 iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet];
94 break;
95 }
96 if (cTries >= 16)
97 {
98 iGipCpu = UINT16_MAX;
99 break;
100 }
101 cTries++;
102 }
103 }
104 else
105 {
106 /* Get APIC ID via the slow CPUID instruction, requires looping. */
107 uint32_t cTries = 0;
108 for (;;)
109 {
110 uint8_t idApic = ASMGetApicId();
111 uTsc = ASMReadTSC();
112 if (RT_LIKELY(ASMGetApicId() == idApic))
113 {
114 iGipCpu = pGip->aiCpuFromApicId[idApic];
115 break;
116 }
117 if (cTries >= 16)
118 {
119 iGipCpu = UINT16_MAX;
120 break;
121 }
122 cTries++;
123 }
124 }
125#elif defined(IN_RING0)
126 /* Ring-0: Use use RTMpCpuId(), no loops. */
127 RTCCUINTREG uFlags = ASMIntDisableFlags();
128 int iCpuSet = RTMpCpuIdToSetIndex(RTMpCpuId());
129 if (RT_LIKELY((unsigned)iCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)))
130 iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet];
131 else
132 iGipCpu = UINT16_MAX;
133 uTsc = ASMReadTSC();
134 ASMSetFlags(uFlags);
135
136# elif defined(IN_RC)
137 /* Raw-mode context: We can get the host CPU set index via VMCPU, no loops. */
138 RTCCUINTREG uFlags = ASMIntDisableFlags(); /* Are already disable, but play safe. */
139 uint32_t iCpuSet = VMMGetCpu(&g_VM)->iHostCpuSet;
140 if (RT_LIKELY(iCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)))
141 iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet];
142 else
143 iGipCpu = UINT16_MAX;
144 uTsc = ASMReadTSC();
145 ASMSetFlags(uFlags);
146#else
147# error "IN_RING3, IN_RC or IN_RING0 must be defined!"
148#endif
149
150 /*
151 * If the delta is valid, apply it.
152 */
153 if (RT_LIKELY(iGipCpu < pGip->cCpus))
154 {
155 int64_t iTscDelta = pGip->aCPUs[iGipCpu].i64TSCDelta;
156 if (RT_LIKELY(iTscDelta != INT64_MAX))
157 return uTsc - iTscDelta;
158
159# ifdef IN_RING3
160 /*
161 * The delta needs calculating, call supdrv to get the TSC.
162 */
163 int rc = SUPR3ReadTsc(&uTsc, NULL);
164 if (RT_SUCCESS(rc))
165 return uTsc;
166 AssertMsgFailed(("SUPR3ReadTsc -> %Rrc\n", rc));
167 uTsc = ASMReadTSC();
168# endif /* IN_RING3 */
169 }
170
171 /*
172 * This shouldn't happen, especially not in ring-3 and raw-mode context.
173 * But if it does, return something that's half useful.
174 */
175 AssertMsgFailed(("iGipCpu=%d (%#x) cCpus=%d fGetGipCpu=%#x\n", iGipCpu, iGipCpu, pGip->cCpus, pGip->fGetGipCpu));
176 return uTsc;
177}
178
179
180/**
181 * Internal worker for getting the GIP CPU array index for the calling CPU.
182 *
183 * @returns Index into SUPGLOBALINFOPAGE::aCPUs or UINT16_MAX.
184 * @param pGip The GIP.
185 */
186DECLINLINE(uint16_t) supGetGipCpuIndex(PSUPGLOBALINFOPAGE pGip)
187{
188 uint16_t iGipCpu;
189#ifdef IN_RING3
190 if (pGip->fGetGipCpu & SUPGIPGETCPU_IDTR_LIMIT_MASK_MAX_SET_CPUS)
191 {
192 /* Storing the IDTR is normally very fast. */
193 uint16_t cbLim = ASMGetIdtrLimit();
194 uint16_t iCpuSet = cbLim - 256 * (ARCH_BITS == 64 ? 16 : 8);
195 iCpuSet &= RTCPUSET_MAX_CPUS - 1;
196 iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet];
197 }
198 else if (pGip->fGetGipCpu & SUPGIPGETCPU_RDTSCP_MASK_MAX_SET_CPUS)
199 {
200 /* RDTSCP gives us what need need and more. */
201 uint32_t iCpuSet;
202 ASMReadTscWithAux(&iCpuSet);
203 iCpuSet &= RTCPUSET_MAX_CPUS - 1;
204 iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet];
205 }
206 else
207 {
208 /* Get APIC ID via the slow CPUID instruction. */
209 uint8_t idApic = ASMGetApicId();
210 iGipCpu = pGip->aiCpuFromApicId[idApic];
211 }
212#elif defined(IN_RING0)
213 /* Ring-0: Use use RTMpCpuId() (disables cli to avoid host OS assertions about unsafe CPU number usage). */
214 RTCCUINTREG uFlags = ASMIntDisableFlags();
215 int iCpuSet = RTMpCpuIdToSetIndex(RTMpCpuId());
216 if (RT_LIKELY((unsigned)iCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)))
217 iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet];
218 else
219 iGipCpu = UINT16_MAX;
220 ASMSetFlags(uFlags);
221
222# elif defined(IN_RC)
223 /* Raw-mode context: We can get the host CPU set index via VMCPU. */
224 uint32_t iCpuSet = VMMGetCpu(&g_VM)->iHostCpuSet;
225 if (RT_LIKELY(iCpuSet < RT_ELEMENTS(pGip->aiCpuFromCpuSetIdx)))
226 iGipCpu = pGip->aiCpuFromCpuSetIdx[iCpuSet];
227 else
228 iGipCpu = UINT16_MAX;
229#else
230# error "IN_RING3, IN_RC or IN_RING0 must be defined!"
231#endif
232 return iGipCpu;
233}
234
235
236/**
237 * Slow path in SUPGetTscDelta, don't call directly.
238 *
239 * @returns See SUPGetTscDelta.
240 * @param pGip The GIP.
241 * @internal
242 */
243SUPDECL(uint64_t) SUPGetTscDeltaSlow(PSUPGLOBALINFOPAGE pGip)
244{
245 uint16_t iGipCpu = supGetGipCpuIndex(pGip);
246 if (RT_LIKELY(iGipCpu < pGip->cCpus))
247 {
248 int64_t iTscDelta = pGip->aCPUs[iGipCpu].i64TSCDelta;
249 if (iTscDelta != INT64_MAX)
250 return iTscDelta;
251 }
252 AssertFailed();
253 return 0;
254}
255
256
257/**
258 * Slow path in SUPGetCpuHzFromGip, don't call directly.
259 *
260 * @returns See SUPGetCpuHzFromGip.
261 * @param pGip The GIP.
262 * @internal
263 */
264SUPDECL(uint64_t) SUPGetCpuHzFromGipForAsyncMode(PSUPGLOBALINFOPAGE pGip)
265{
266 uint16_t iGipCpu = supGetGipCpuIndex(pGip);
267 if (RT_LIKELY(iGipCpu < pGip->cCpus))
268 return pGip->aCPUs[iGipCpu].u64CpuHz;
269 AssertFailed();
270 return pGip->u64CpuHz;
271}
272
273
274/**
275 * Worker for SUPIsTscFreqCompatible().
276 *
277 * @returns true if it's compatible, false otherwise.
278 * @param uBaseCpuHz The reference CPU frequency of the system.
279 * @param uCpuHz The CPU frequency to compare with the base.
280 * @param fRelax Whether to use a more relaxed threshold (like
281 * for when running in a virtualized environment).
282 *
283 * @remarks Don't use directly, use SUPIsTscFreqCompatible() instead. This is
284 * to be used by tstGIP-2 or the like.
285 */
286SUPDECL(bool) SUPIsTscFreqCompatibleEx(uint64_t uBaseCpuHz, uint64_t uCpuHz, bool fRelax)
287{
288 if (uBaseCpuHz != uCpuHz)
289 {
290 /* Arbitrary tolerance threshold, tweak later if required, perhaps
291 more tolerance on lower frequencies and less tolerance on higher. */
292 uint16_t uFact = !fRelax ? 666 /* 0.15% */ : 125 /* 0.8% */;
293 uint64_t uThr = uBaseCpuHz / uFact;
294 uint64_t uLo = uBaseCpuHz - uThr;
295 uint64_t uHi = uBaseCpuHz + uThr;
296 if ( uCpuHz < uLo
297 || uCpuHz > uHi)
298 return false;
299 }
300 return true;
301}
302
303
304/**
305 * Checks if the provided TSC frequency is close enough to the computed TSC
306 * frequency of the host.
307 *
308 * @returns true if it's compatible, false otherwise.
309 * @param uCpuHz The TSC frequency to check.
310 * @param puGipCpuHz Where to store the GIP TSC frequency used
311 * during the compatibility test - optional.
312 * @param fRelax Whether to use a more relaxed threshold (like
313 * for when running in a virtualized environment).
314 */
315SUPDECL(bool) SUPIsTscFreqCompatible(uint64_t uCpuHz, uint64_t *puGipCpuHz, bool fRelax)
316{
317 PSUPGLOBALINFOPAGE pGip = g_pSUPGlobalInfoPage;
318 bool fCompat = false;
319 uint64_t uGipCpuHz = 0;
320 if ( pGip
321 && pGip->u32Mode != SUPGIPMODE_ASYNC_TSC)
322 {
323 uGipCpuHz = pGip->u64CpuHz;
324 fCompat = SUPIsTscFreqCompatibleEx(uGipCpuHz, uCpuHz, fRelax);
325 }
326 if (puGipCpuHz)
327 *puGipCpuHz = uGipCpuHz;
328 return fCompat;
329}
330
331#endif /* RT_ARCH_AMD64 || RT_ARCH_X86 */
332
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