VirtualBox

source: vbox/trunk/src/VBox/VMM/VMMR0/CPUMR0.cpp@ 62338

Last change on this file since 62338 was 61317, checked in by vboxsync, 8 years ago

CPUM,HM: CPUM must tell VT-x that it modified the host CR0 because it caches the value in the VMCS and state corruption may ensue if it restores it because we'll take a #NM when saving the guest state, probably ending up with the FPU state of the EMT instead.

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1/* $Id: CPUMR0.cpp 61317 2016-05-31 04:55:10Z vboxsync $ */
2/** @file
3 * CPUM - Host Context Ring 0.
4 */
5
6/*
7 * Copyright (C) 2006-2015 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_CPUM
23#include <VBox/vmm/cpum.h>
24#include "CPUMInternal.h"
25#include <VBox/vmm/vm.h>
26#include <VBox/err.h>
27#include <VBox/log.h>
28#include <VBox/vmm/hm.h>
29#include <iprt/assert.h>
30#include <iprt/asm-amd64-x86.h>
31#ifdef VBOX_WITH_VMMR0_DISABLE_LAPIC_NMI
32# include <iprt/mem.h>
33# include <iprt/memobj.h>
34# include <VBox/apic.h>
35#endif
36#include <iprt/x86.h>
37
38
39/*********************************************************************************************************************************
40* Structures and Typedefs *
41*********************************************************************************************************************************/
42#ifdef VBOX_WITH_VMMR0_DISABLE_LAPIC_NMI
43/**
44 * Local APIC mappings.
45 */
46typedef struct CPUMHOSTLAPIC
47{
48 /** Indicates that the entry is in use and have valid data. */
49 bool fEnabled;
50 /** Whether it's operating in X2APIC mode (EXTD). */
51 bool fX2Apic;
52 /** The APIC version number. */
53 uint32_t uVersion;
54 /** The physical address of the APIC registers. */
55 RTHCPHYS PhysBase;
56 /** The memory object entering the physical address. */
57 RTR0MEMOBJ hMemObj;
58 /** The mapping object for hMemObj. */
59 RTR0MEMOBJ hMapObj;
60 /** The mapping address APIC registers.
61 * @remarks Different CPUs may use the same physical address to map their
62 * APICs, so this pointer is only valid when on the CPU owning the
63 * APIC. */
64 void *pv;
65} CPUMHOSTLAPIC;
66#endif
67
68
69/*********************************************************************************************************************************
70* Global Variables *
71*********************************************************************************************************************************/
72#ifdef VBOX_WITH_VMMR0_DISABLE_LAPIC_NMI
73static CPUMHOSTLAPIC g_aLApics[RTCPUSET_MAX_CPUS];
74#endif
75
76/**
77 * CPUID bits to unify among all cores.
78 */
79static struct
80{
81 uint32_t uLeaf; /**< Leaf to check. */
82 uint32_t uEcx; /**< which bits in ecx to unify between CPUs. */
83 uint32_t uEdx; /**< which bits in edx to unify between CPUs. */
84}
85const g_aCpuidUnifyBits[] =
86{
87 {
88 0x00000001,
89 X86_CPUID_FEATURE_ECX_CX16 | X86_CPUID_FEATURE_ECX_MONITOR,
90 X86_CPUID_FEATURE_EDX_CX8
91 }
92};
93
94
95
96/*********************************************************************************************************************************
97* Internal Functions *
98*********************************************************************************************************************************/
99#ifdef VBOX_WITH_VMMR0_DISABLE_LAPIC_NMI
100static int cpumR0MapLocalApics(void);
101static void cpumR0UnmapLocalApics(void);
102#endif
103static int cpumR0SaveHostDebugState(PVMCPU pVCpu);
104
105
106/**
107 * Does the Ring-0 CPU initialization once during module load.
108 * XXX Host-CPU hot-plugging?
109 */
110VMMR0_INT_DECL(int) CPUMR0ModuleInit(void)
111{
112 int rc = VINF_SUCCESS;
113#ifdef VBOX_WITH_VMMR0_DISABLE_LAPIC_NMI
114 rc = cpumR0MapLocalApics();
115#endif
116 return rc;
117}
118
119
120/**
121 * Terminate the module.
122 */
123VMMR0_INT_DECL(int) CPUMR0ModuleTerm(void)
124{
125#ifdef VBOX_WITH_VMMR0_DISABLE_LAPIC_NMI
126 cpumR0UnmapLocalApics();
127#endif
128 return VINF_SUCCESS;
129}
130
131
132/**
133 *
134 *
135 * Check the CPUID features of this particular CPU and disable relevant features
136 * for the guest which do not exist on this CPU. We have seen systems where the
137 * X86_CPUID_FEATURE_ECX_MONITOR feature flag is only set on some host CPUs, see
138 * @bugref{5436}.
139 *
140 * @note This function might be called simultaneously on more than one CPU!
141 *
142 * @param idCpu The identifier for the CPU the function is called on.
143 * @param pvUser1 Pointer to the VM structure.
144 * @param pvUser2 Ignored.
145 */
146static DECLCALLBACK(void) cpumR0CheckCpuid(RTCPUID idCpu, void *pvUser1, void *pvUser2)
147{
148 PVM pVM = (PVM)pvUser1;
149
150 NOREF(idCpu); NOREF(pvUser2);
151 for (uint32_t i = 0; i < RT_ELEMENTS(g_aCpuidUnifyBits); i++)
152 {
153 /* Note! Cannot use cpumCpuIdGetLeaf from here because we're not
154 necessarily in the VM process context. So, we using the
155 legacy arrays as temporary storage. */
156
157 uint32_t uLeaf = g_aCpuidUnifyBits[i].uLeaf;
158 PCPUMCPUID pLegacyLeaf;
159 if (uLeaf < RT_ELEMENTS(pVM->cpum.s.aGuestCpuIdPatmStd))
160 pLegacyLeaf = &pVM->cpum.s.aGuestCpuIdPatmStd[uLeaf];
161 else if (uLeaf - UINT32_C(0x80000000) < RT_ELEMENTS(pVM->cpum.s.aGuestCpuIdPatmExt))
162 pLegacyLeaf = &pVM->cpum.s.aGuestCpuIdPatmExt[uLeaf - UINT32_C(0x80000000)];
163 else if (uLeaf - UINT32_C(0xc0000000) < RT_ELEMENTS(pVM->cpum.s.aGuestCpuIdPatmCentaur))
164 pLegacyLeaf = &pVM->cpum.s.aGuestCpuIdPatmCentaur[uLeaf - UINT32_C(0xc0000000)];
165 else
166 continue;
167
168 uint32_t eax, ebx, ecx, edx;
169 ASMCpuIdExSlow(uLeaf, 0, 0, 0, &eax, &ebx, &ecx, &edx);
170
171 ASMAtomicAndU32(&pLegacyLeaf->uEcx, ecx | ~g_aCpuidUnifyBits[i].uEcx);
172 ASMAtomicAndU32(&pLegacyLeaf->uEdx, edx | ~g_aCpuidUnifyBits[i].uEdx);
173 }
174}
175
176
177/**
178 * Does Ring-0 CPUM initialization.
179 *
180 * This is mainly to check that the Host CPU mode is compatible
181 * with VBox.
182 *
183 * @returns VBox status code.
184 * @param pVM The cross context VM structure.
185 */
186VMMR0_INT_DECL(int) CPUMR0InitVM(PVM pVM)
187{
188 LogFlow(("CPUMR0Init: %p\n", pVM));
189
190 /*
191 * Check CR0 & CR4 flags.
192 */
193 uint32_t u32CR0 = ASMGetCR0();
194 if ((u32CR0 & (X86_CR0_PE | X86_CR0_PG)) != (X86_CR0_PE | X86_CR0_PG)) /* a bit paranoid perhaps.. */
195 {
196 Log(("CPUMR0Init: PE or PG not set. cr0=%#x\n", u32CR0));
197 return VERR_UNSUPPORTED_CPU_MODE;
198 }
199
200 /*
201 * Check for sysenter and syscall usage.
202 */
203 if (ASMHasCpuId())
204 {
205 /*
206 * SYSENTER/SYSEXIT
207 *
208 * Intel docs claim you should test both the flag and family, model &
209 * stepping because some Pentium Pro CPUs have the SEP cpuid flag set,
210 * but don't support it. AMD CPUs may support this feature in legacy
211 * mode, they've banned it from long mode. Since we switch to 32-bit
212 * mode when entering raw-mode context the feature would become
213 * accessible again on AMD CPUs, so we have to check regardless of
214 * host bitness.
215 */
216 uint32_t u32CpuVersion;
217 uint32_t u32Dummy;
218 uint32_t fFeatures;
219 ASMCpuId(1, &u32CpuVersion, &u32Dummy, &u32Dummy, &fFeatures);
220 uint32_t const u32Family = u32CpuVersion >> 8;
221 uint32_t const u32Model = (u32CpuVersion >> 4) & 0xF;
222 uint32_t const u32Stepping = u32CpuVersion & 0xF;
223 if ( (fFeatures & X86_CPUID_FEATURE_EDX_SEP)
224 && ( u32Family != 6 /* (> pentium pro) */
225 || u32Model >= 3
226 || u32Stepping >= 3
227 || !ASMIsIntelCpu())
228 )
229 {
230 /*
231 * Read the MSR and see if it's in use or not.
232 */
233 uint32_t u32 = ASMRdMsr_Low(MSR_IA32_SYSENTER_CS);
234 if (u32)
235 {
236 pVM->cpum.s.fHostUseFlags |= CPUM_USE_SYSENTER;
237 Log(("CPUMR0Init: host uses sysenter cs=%08x%08x\n", ASMRdMsr_High(MSR_IA32_SYSENTER_CS), u32));
238 }
239 }
240
241 /*
242 * SYSCALL/SYSRET
243 *
244 * This feature is indicated by the SEP bit returned in EDX by CPUID
245 * function 0x80000001. Intel CPUs only supports this feature in
246 * long mode. Since we're not running 64-bit guests in raw-mode there
247 * are no issues with 32-bit intel hosts.
248 */
249 uint32_t cExt = 0;
250 ASMCpuId(0x80000000, &cExt, &u32Dummy, &u32Dummy, &u32Dummy);
251 if (ASMIsValidExtRange(cExt))
252 {
253 uint32_t fExtFeaturesEDX = ASMCpuId_EDX(0x80000001);
254 if (fExtFeaturesEDX & X86_CPUID_EXT_FEATURE_EDX_SYSCALL)
255 {
256#ifdef RT_ARCH_X86
257 if (!ASMIsIntelCpu())
258#endif
259 {
260 uint64_t fEfer = ASMRdMsr(MSR_K6_EFER);
261 if (fEfer & MSR_K6_EFER_SCE)
262 {
263 pVM->cpum.s.fHostUseFlags |= CPUM_USE_SYSCALL;
264 Log(("CPUMR0Init: host uses syscall\n"));
265 }
266 }
267 }
268 }
269
270 /*
271 * Unify/cross check some CPUID feature bits on all available CPU cores
272 * and threads. We've seen CPUs where the monitor support differed.
273 *
274 * Because the hyper heap isn't always mapped into ring-0, we cannot
275 * access it from a RTMpOnAll callback. We use the legacy CPUID arrays
276 * as temp ring-0 accessible memory instead, ASSUMING that they're all
277 * up to date when we get here.
278 */
279 RTMpOnAll(cpumR0CheckCpuid, pVM, NULL);
280
281 for (uint32_t i = 0; i < RT_ELEMENTS(g_aCpuidUnifyBits); i++)
282 {
283 bool fIgnored;
284 uint32_t uLeaf = g_aCpuidUnifyBits[i].uLeaf;
285 PCPUMCPUIDLEAF pLeaf = cpumCpuIdGetLeafEx(pVM, uLeaf, 0, &fIgnored);
286 if (pLeaf)
287 {
288 PCPUMCPUID pLegacyLeaf;
289 if (uLeaf < RT_ELEMENTS(pVM->cpum.s.aGuestCpuIdPatmStd))
290 pLegacyLeaf = &pVM->cpum.s.aGuestCpuIdPatmStd[uLeaf];
291 else if (uLeaf - UINT32_C(0x80000000) < RT_ELEMENTS(pVM->cpum.s.aGuestCpuIdPatmExt))
292 pLegacyLeaf = &pVM->cpum.s.aGuestCpuIdPatmExt[uLeaf - UINT32_C(0x80000000)];
293 else if (uLeaf - UINT32_C(0xc0000000) < RT_ELEMENTS(pVM->cpum.s.aGuestCpuIdPatmCentaur))
294 pLegacyLeaf = &pVM->cpum.s.aGuestCpuIdPatmCentaur[uLeaf - UINT32_C(0xc0000000)];
295 else
296 continue;
297
298 pLeaf->uEcx = pLegacyLeaf->uEcx;
299 pLeaf->uEdx = pLegacyLeaf->uEdx;
300 }
301 }
302
303 }
304
305
306 /*
307 * Check if debug registers are armed.
308 * This ASSUMES that DR7.GD is not set, or that it's handled transparently!
309 */
310 uint32_t u32DR7 = ASMGetDR7();
311 if (u32DR7 & X86_DR7_ENABLED_MASK)
312 {
313 for (VMCPUID i = 0; i < pVM->cCpus; i++)
314 pVM->aCpus[i].cpum.s.fUseFlags |= CPUM_USE_DEBUG_REGS_HOST;
315 Log(("CPUMR0Init: host uses debug registers (dr7=%x)\n", u32DR7));
316 }
317
318 return VINF_SUCCESS;
319}
320
321
322/**
323 * Trap handler for device-not-available fault (\#NM).
324 * Device not available, FP or (F)WAIT instruction.
325 *
326 * @returns VBox status code.
327 * @retval VINF_SUCCESS if the guest FPU state is loaded.
328 * @retval VINF_EM_RAW_GUEST_TRAP if it is a guest trap.
329 * @retval VINF_CPUM_HOST_CR0_MODIFIED if we modified the host CR0.
330 *
331 * @param pVM The cross context VM structure.
332 * @param pVCpu The cross context virtual CPU structure.
333 */
334VMMR0_INT_DECL(int) CPUMR0Trap07Handler(PVM pVM, PVMCPU pVCpu)
335{
336 Assert(pVM->cpum.s.HostFeatures.fFxSaveRstor);
337 Assert(ASMGetCR4() & X86_CR4_OSFXSR);
338
339 /* If the FPU state has already been loaded, then it's a guest trap. */
340 if (CPUMIsGuestFPUStateActive(pVCpu))
341 {
342 Assert( ((pVCpu->cpum.s.Guest.cr0 & (X86_CR0_MP | X86_CR0_EM | X86_CR0_TS)) == (X86_CR0_MP | X86_CR0_TS))
343 || ((pVCpu->cpum.s.Guest.cr0 & (X86_CR0_MP | X86_CR0_EM | X86_CR0_TS)) == (X86_CR0_MP | X86_CR0_TS | X86_CR0_EM)));
344 return VINF_EM_RAW_GUEST_TRAP;
345 }
346
347 /*
348 * There are two basic actions:
349 * 1. Save host fpu and restore guest fpu.
350 * 2. Generate guest trap.
351 *
352 * When entering the hypervisor we'll always enable MP (for proper wait
353 * trapping) and TS (for intercepting all fpu/mmx/sse stuff). The EM flag
354 * is taken from the guest OS in order to get proper SSE handling.
355 *
356 *
357 * Actions taken depending on the guest CR0 flags:
358 *
359 * 3 2 1
360 * TS | EM | MP | FPUInstr | WAIT :: VMM Action
361 * ------------------------------------------------------------------------
362 * 0 | 0 | 0 | Exec | Exec :: Clear TS & MP, Save HC, Load GC.
363 * 0 | 0 | 1 | Exec | Exec :: Clear TS, Save HC, Load GC.
364 * 0 | 1 | 0 | #NM | Exec :: Clear TS & MP, Save HC, Load GC.
365 * 0 | 1 | 1 | #NM | Exec :: Clear TS, Save HC, Load GC.
366 * 1 | 0 | 0 | #NM | Exec :: Clear MP, Save HC, Load GC. (EM is already cleared.)
367 * 1 | 0 | 1 | #NM | #NM :: Go to guest taking trap there.
368 * 1 | 1 | 0 | #NM | Exec :: Clear MP, Save HC, Load GC. (EM is already set.)
369 * 1 | 1 | 1 | #NM | #NM :: Go to guest taking trap there.
370 */
371
372 switch (pVCpu->cpum.s.Guest.cr0 & (X86_CR0_MP | X86_CR0_EM | X86_CR0_TS))
373 {
374 case X86_CR0_MP | X86_CR0_TS:
375 case X86_CR0_MP | X86_CR0_TS | X86_CR0_EM:
376 return VINF_EM_RAW_GUEST_TRAP;
377 default:
378 break;
379 }
380
381 return CPUMR0LoadGuestFPU(pVM, pVCpu);
382}
383
384
385/**
386 * Saves the host-FPU/XMM state (if necessary) and (always) loads the guest-FPU
387 * state into the CPU.
388 *
389 * @returns VINF_SUCCESS on success, host CR0 unmodified.
390 * @returns VINF_CPUM_HOST_CR0_MODIFIED on success when the host CR0 was
391 * modified and VT-x needs to update the value in the VMCS.
392 *
393 * @param pVM The cross context VM structure.
394 * @param pVCpu The cross context virtual CPU structure.
395 */
396VMMR0_INT_DECL(int) CPUMR0LoadGuestFPU(PVM pVM, PVMCPU pVCpu)
397{
398 int rc = VINF_SUCCESS;
399 Assert(!RTThreadPreemptIsEnabled(NIL_RTTHREAD));
400 Assert(!(pVCpu->cpum.s.fUseFlags & CPUM_USED_FPU_GUEST));
401 Assert(!(pVCpu->cpum.s.fUseFlags & CPUM_SYNC_FPU_STATE));
402
403#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS)
404 if (CPUMIsGuestInLongModeEx(&pVCpu->cpum.s.Guest))
405 {
406 Assert(!(pVCpu->cpum.s.fUseFlags & CPUM_USED_MANUAL_XMM_RESTORE));
407
408 /* Save the host state if necessary. */
409 if (!(pVCpu->cpum.s.fUseFlags & CPUM_USED_FPU_HOST))
410 rc = cpumRZSaveHostFPUState(&pVCpu->cpum.s);
411
412 /* Restore the state on entry as we need to be in 64-bit mode to access the full state. */
413 pVCpu->cpum.s.fUseFlags |= CPUM_SYNC_FPU_STATE;
414
415 Assert( (pVCpu->cpum.s.fUseFlags & (CPUM_USED_FPU_HOST | CPUM_USED_FPU_SINCE_REM))
416 == (CPUM_USED_FPU_HOST | CPUM_USED_FPU_SINCE_REM));
417 }
418 else
419#endif
420 {
421 if (!pVM->cpum.s.HostFeatures.fLeakyFxSR)
422 {
423 Assert(!(pVCpu->cpum.s.fUseFlags & CPUM_USED_MANUAL_XMM_RESTORE));
424 rc = cpumR0SaveHostRestoreGuestFPUState(&pVCpu->cpum.s);
425 }
426 else
427 {
428 Assert(!(pVCpu->cpum.s.fUseFlags & CPUM_USED_MANUAL_XMM_RESTORE) || (pVCpu->cpum.s.fUseFlags & CPUM_USED_FPU_HOST));
429 /** @todo r=ramshankar: Can't we used a cached value here
430 * instead of reading the MSR? host EFER doesn't usually
431 * change. */
432 uint64_t uHostEfer = ASMRdMsr(MSR_K6_EFER);
433 if (!(uHostEfer & MSR_K6_EFER_FFXSR))
434 rc = cpumR0SaveHostRestoreGuestFPUState(&pVCpu->cpum.s);
435 else
436 {
437 RTCCUINTREG const uSavedFlags = ASMIntDisableFlags();
438 pVCpu->cpum.s.fUseFlags |= CPUM_USED_MANUAL_XMM_RESTORE;
439 ASMWrMsr(MSR_K6_EFER, uHostEfer & ~MSR_K6_EFER_FFXSR);
440 rc = cpumR0SaveHostRestoreGuestFPUState(&pVCpu->cpum.s);
441 ASMWrMsr(MSR_K6_EFER, uHostEfer | MSR_K6_EFER_FFXSR);
442 ASMSetFlags(uSavedFlags);
443 }
444 }
445 Assert( (pVCpu->cpum.s.fUseFlags & (CPUM_USED_FPU_GUEST | CPUM_USED_FPU_HOST | CPUM_USED_FPU_SINCE_REM))
446 == (CPUM_USED_FPU_GUEST | CPUM_USED_FPU_HOST | CPUM_USED_FPU_SINCE_REM));
447 }
448 return rc;
449}
450
451
452/**
453 * Saves the guest FPU/XMM state if needed, restores the host FPU/XMM state as
454 * needed.
455 *
456 * @returns true if we saved the guest state.
457 * @param pVCpu The cross context virtual CPU structure.
458 */
459VMMR0_INT_DECL(bool) CPUMR0FpuStateMaybeSaveGuestAndRestoreHost(PVMCPU pVCpu)
460{
461 bool fSavedGuest;
462 Assert(pVCpu->CTX_SUFF(pVM)->cpum.s.HostFeatures.fFxSaveRstor);
463 Assert(ASMGetCR4() & X86_CR4_OSFXSR);
464 if (pVCpu->cpum.s.fUseFlags & (CPUM_USED_FPU_GUEST | CPUM_USED_FPU_HOST))
465 {
466 fSavedGuest = RT_BOOL(pVCpu->cpum.s.fUseFlags & CPUM_USED_FPU_GUEST);
467#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS)
468 if (CPUMIsGuestInLongModeEx(&pVCpu->cpum.s.Guest))
469 {
470 if (pVCpu->cpum.s.fUseFlags & CPUM_USED_FPU_GUEST)
471 {
472 Assert(!(pVCpu->cpum.s.fUseFlags & CPUM_SYNC_FPU_STATE));
473 HMR0SaveFPUState(pVCpu->CTX_SUFF(pVM), pVCpu, &pVCpu->cpum.s.Guest);
474 }
475 else
476 pVCpu->cpum.s.fUseFlags &= ~CPUM_SYNC_FPU_STATE;
477 cpumR0RestoreHostFPUState(&pVCpu->cpum.s);
478 }
479 else
480#endif
481 {
482 if (!(pVCpu->cpum.s.fUseFlags & CPUM_USED_MANUAL_XMM_RESTORE))
483 cpumR0SaveGuestRestoreHostFPUState(&pVCpu->cpum.s);
484 else
485 {
486 /* Temporarily clear MSR_K6_EFER_FFXSR or else we'll be unable to
487 save/restore the XMM state with fxsave/fxrstor. */
488 uint64_t uHostEfer = ASMRdMsr(MSR_K6_EFER);
489 if (uHostEfer & MSR_K6_EFER_FFXSR)
490 {
491 RTCCUINTREG const uSavedFlags = ASMIntDisableFlags();
492 ASMWrMsr(MSR_K6_EFER, uHostEfer & ~MSR_K6_EFER_FFXSR);
493 cpumR0SaveGuestRestoreHostFPUState(&pVCpu->cpum.s);
494 ASMWrMsr(MSR_K6_EFER, uHostEfer | MSR_K6_EFER_FFXSR);
495 ASMSetFlags(uSavedFlags);
496 }
497 else
498 cpumR0SaveGuestRestoreHostFPUState(&pVCpu->cpum.s);
499 pVCpu->cpum.s.fUseFlags &= ~CPUM_USED_MANUAL_XMM_RESTORE;
500 }
501 }
502 }
503 else
504 fSavedGuest = false;
505 Assert(!( pVCpu->cpum.s.fUseFlags
506 & (CPUM_USED_FPU_GUEST | CPUM_USED_FPU_HOST | CPUM_SYNC_FPU_STATE | CPUM_USED_MANUAL_XMM_RESTORE)));
507 return fSavedGuest;
508}
509
510
511/**
512 * Saves the host debug state, setting CPUM_USED_HOST_DEBUG_STATE and loading
513 * DR7 with safe values.
514 *
515 * @returns VBox status code.
516 * @param pVCpu The cross context virtual CPU structure.
517 */
518static int cpumR0SaveHostDebugState(PVMCPU pVCpu)
519{
520 /*
521 * Save the host state.
522 */
523 pVCpu->cpum.s.Host.dr0 = ASMGetDR0();
524 pVCpu->cpum.s.Host.dr1 = ASMGetDR1();
525 pVCpu->cpum.s.Host.dr2 = ASMGetDR2();
526 pVCpu->cpum.s.Host.dr3 = ASMGetDR3();
527 pVCpu->cpum.s.Host.dr6 = ASMGetDR6();
528 /** @todo dr7 might already have been changed to 0x400; don't care right now as it's harmless. */
529 pVCpu->cpum.s.Host.dr7 = ASMGetDR7();
530
531 /* Preemption paranoia. */
532 ASMAtomicOrU32(&pVCpu->cpum.s.fUseFlags, CPUM_USED_DEBUG_REGS_HOST);
533
534 /*
535 * Make sure DR7 is harmless or else we could trigger breakpoints when
536 * load guest or hypervisor DRx values later.
537 */
538 if (pVCpu->cpum.s.Host.dr7 != X86_DR7_INIT_VAL)
539 ASMSetDR7(X86_DR7_INIT_VAL);
540
541 return VINF_SUCCESS;
542}
543
544
545/**
546 * Saves the guest DRx state residing in host registers and restore the host
547 * register values.
548 *
549 * The guest DRx state is only saved if CPUMR0LoadGuestDebugState was called,
550 * since it's assumed that we're shadowing the guest DRx register values
551 * accurately when using the combined hypervisor debug register values
552 * (CPUMR0LoadHyperDebugState).
553 *
554 * @returns true if either guest or hypervisor debug registers were loaded.
555 * @param pVCpu The cross context virtual CPU structure of the calling EMT.
556 * @param fDr6 Whether to include DR6 or not.
557 * @thread EMT(pVCpu)
558 */
559VMMR0_INT_DECL(bool) CPUMR0DebugStateMaybeSaveGuestAndRestoreHost(PVMCPU pVCpu, bool fDr6)
560{
561 Assert(!RTThreadPreemptIsEnabled(NIL_RTTHREAD));
562 bool const fDrXLoaded = RT_BOOL(pVCpu->cpum.s.fUseFlags & (CPUM_USED_DEBUG_REGS_GUEST | CPUM_USED_DEBUG_REGS_HYPER));
563
564 /*
565 * Do we need to save the guest DRx registered loaded into host registers?
566 * (DR7 and DR6 (if fDr6 is true) are left to the caller.)
567 */
568 if (pVCpu->cpum.s.fUseFlags & CPUM_USED_DEBUG_REGS_GUEST)
569 {
570#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS)
571 if (CPUMIsGuestInLongModeEx(&pVCpu->cpum.s.Guest))
572 {
573 uint64_t uDr6 = pVCpu->cpum.s.Guest.dr[6];
574 HMR0SaveDebugState(pVCpu->CTX_SUFF(pVM), pVCpu, &pVCpu->cpum.s.Guest);
575 if (!fDr6)
576 pVCpu->cpum.s.Guest.dr[6] = uDr6;
577 }
578 else
579#endif
580 {
581 pVCpu->cpum.s.Guest.dr[0] = ASMGetDR0();
582 pVCpu->cpum.s.Guest.dr[1] = ASMGetDR1();
583 pVCpu->cpum.s.Guest.dr[2] = ASMGetDR2();
584 pVCpu->cpum.s.Guest.dr[3] = ASMGetDR3();
585 if (fDr6)
586 pVCpu->cpum.s.Guest.dr[6] = ASMGetDR6();
587 }
588 }
589 ASMAtomicAndU32(&pVCpu->cpum.s.fUseFlags, ~( CPUM_USED_DEBUG_REGS_GUEST | CPUM_USED_DEBUG_REGS_HYPER
590 | CPUM_SYNC_DEBUG_REGS_GUEST | CPUM_SYNC_DEBUG_REGS_HYPER));
591
592 /*
593 * Restore the host's debug state. DR0-3, DR6 and only then DR7!
594 */
595 if (pVCpu->cpum.s.fUseFlags & CPUM_USED_DEBUG_REGS_HOST)
596 {
597 /* A bit of paranoia first... */
598 uint64_t uCurDR7 = ASMGetDR7();
599 if (uCurDR7 != X86_DR7_INIT_VAL)
600 ASMSetDR7(X86_DR7_INIT_VAL);
601
602 ASMSetDR0(pVCpu->cpum.s.Host.dr0);
603 ASMSetDR1(pVCpu->cpum.s.Host.dr1);
604 ASMSetDR2(pVCpu->cpum.s.Host.dr2);
605 ASMSetDR3(pVCpu->cpum.s.Host.dr3);
606 /** @todo consider only updating if they differ, esp. DR6. Need to figure how
607 * expensive DRx reads are over DRx writes. */
608 ASMSetDR6(pVCpu->cpum.s.Host.dr6);
609 ASMSetDR7(pVCpu->cpum.s.Host.dr7);
610
611 ASMAtomicAndU32(&pVCpu->cpum.s.fUseFlags, ~CPUM_USED_DEBUG_REGS_HOST);
612 }
613
614 return fDrXLoaded;
615}
616
617
618/**
619 * Saves the guest DRx state if it resides host registers.
620 *
621 * This does NOT clear any use flags, so the host registers remains loaded with
622 * the guest DRx state upon return. The purpose is only to make sure the values
623 * in the CPU context structure is up to date.
624 *
625 * @returns true if the host registers contains guest values, false if not.
626 * @param pVCpu The cross context virtual CPU structure of the calling EMT.
627 * @param fDr6 Whether to include DR6 or not.
628 * @thread EMT(pVCpu)
629 */
630VMMR0_INT_DECL(bool) CPUMR0DebugStateMaybeSaveGuest(PVMCPU pVCpu, bool fDr6)
631{
632 /*
633 * Do we need to save the guest DRx registered loaded into host registers?
634 * (DR7 and DR6 (if fDr6 is true) are left to the caller.)
635 */
636 if (pVCpu->cpum.s.fUseFlags & CPUM_USED_DEBUG_REGS_GUEST)
637 {
638#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS)
639 if (CPUMIsGuestInLongModeEx(&pVCpu->cpum.s.Guest))
640 {
641 uint64_t uDr6 = pVCpu->cpum.s.Guest.dr[6];
642 HMR0SaveDebugState(pVCpu->CTX_SUFF(pVM), pVCpu, &pVCpu->cpum.s.Guest);
643 if (!fDr6)
644 pVCpu->cpum.s.Guest.dr[6] = uDr6;
645 }
646 else
647#endif
648 {
649 pVCpu->cpum.s.Guest.dr[0] = ASMGetDR0();
650 pVCpu->cpum.s.Guest.dr[1] = ASMGetDR1();
651 pVCpu->cpum.s.Guest.dr[2] = ASMGetDR2();
652 pVCpu->cpum.s.Guest.dr[3] = ASMGetDR3();
653 if (fDr6)
654 pVCpu->cpum.s.Guest.dr[6] = ASMGetDR6();
655 }
656 return true;
657 }
658 return false;
659}
660
661
662/**
663 * Lazily sync in the debug state.
664 *
665 * @param pVCpu The cross context virtual CPU structure of the calling EMT.
666 * @param fDr6 Whether to include DR6 or not.
667 * @thread EMT(pVCpu)
668 */
669VMMR0_INT_DECL(void) CPUMR0LoadGuestDebugState(PVMCPU pVCpu, bool fDr6)
670{
671 /*
672 * Save the host state and disarm all host BPs.
673 */
674 cpumR0SaveHostDebugState(pVCpu);
675 Assert(ASMGetDR7() == X86_DR7_INIT_VAL);
676
677 /*
678 * Activate the guest state DR0-3.
679 * DR7 and DR6 (if fDr6 is true) are left to the caller.
680 */
681#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS)
682 if (CPUMIsGuestInLongModeEx(&pVCpu->cpum.s.Guest))
683 ASMAtomicOrU32(&pVCpu->cpum.s.fUseFlags, CPUM_SYNC_DEBUG_REGS_GUEST); /* Postpone it to the world switch. */
684 else
685#endif
686 {
687 ASMSetDR0(pVCpu->cpum.s.Guest.dr[0]);
688 ASMSetDR1(pVCpu->cpum.s.Guest.dr[1]);
689 ASMSetDR2(pVCpu->cpum.s.Guest.dr[2]);
690 ASMSetDR3(pVCpu->cpum.s.Guest.dr[3]);
691 if (fDr6)
692 ASMSetDR6(pVCpu->cpum.s.Guest.dr[6]);
693
694 ASMAtomicOrU32(&pVCpu->cpum.s.fUseFlags, CPUM_USED_DEBUG_REGS_GUEST);
695 }
696}
697
698
699/**
700 * Lazily sync in the hypervisor debug state
701 *
702 * @returns VBox status code.
703 * @param pVCpu The cross context virtual CPU structure of the calling EMT.
704 * @param fDr6 Whether to include DR6 or not.
705 * @thread EMT(pVCpu)
706 */
707VMMR0_INT_DECL(void) CPUMR0LoadHyperDebugState(PVMCPU pVCpu, bool fDr6)
708{
709 /*
710 * Save the host state and disarm all host BPs.
711 */
712 cpumR0SaveHostDebugState(pVCpu);
713 Assert(ASMGetDR7() == X86_DR7_INIT_VAL);
714
715 /*
716 * Make sure the hypervisor values are up to date.
717 */
718 CPUMRecalcHyperDRx(pVCpu, UINT8_MAX /* no loading, please */, true);
719
720 /*
721 * Activate the guest state DR0-3.
722 * DR7 and DR6 (if fDr6 is true) are left to the caller.
723 */
724#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS)
725 if (CPUMIsGuestInLongModeEx(&pVCpu->cpum.s.Guest))
726 ASMAtomicOrU32(&pVCpu->cpum.s.fUseFlags, CPUM_SYNC_DEBUG_REGS_HYPER); /* Postpone it. */
727 else
728#endif
729 {
730 ASMSetDR0(pVCpu->cpum.s.Hyper.dr[0]);
731 ASMSetDR1(pVCpu->cpum.s.Hyper.dr[1]);
732 ASMSetDR2(pVCpu->cpum.s.Hyper.dr[2]);
733 ASMSetDR3(pVCpu->cpum.s.Hyper.dr[3]);
734 if (fDr6)
735 ASMSetDR6(X86_DR6_INIT_VAL);
736
737 ASMAtomicOrU32(&pVCpu->cpum.s.fUseFlags, CPUM_USED_DEBUG_REGS_HYPER);
738 }
739}
740
741#ifdef VBOX_WITH_VMMR0_DISABLE_LAPIC_NMI
742
743/**
744 * Per-CPU callback that probes the CPU for APIC support.
745 *
746 * @param idCpu The identifier for the CPU the function is called on.
747 * @param pvUser1 Ignored.
748 * @param pvUser2 Ignored.
749 */
750static DECLCALLBACK(void) cpumR0MapLocalApicCpuProber(RTCPUID idCpu, void *pvUser1, void *pvUser2)
751{
752 NOREF(pvUser1); NOREF(pvUser2);
753 int iCpu = RTMpCpuIdToSetIndex(idCpu);
754 AssertReturnVoid(iCpu >= 0 && (unsigned)iCpu < RT_ELEMENTS(g_aLApics));
755
756 /*
757 * Check for APIC support.
758 */
759 uint32_t uMaxLeaf, u32EBX, u32ECX, u32EDX;
760 ASMCpuId(0, &uMaxLeaf, &u32EBX, &u32ECX, &u32EDX);
761 if ( ( ASMIsIntelCpuEx(u32EBX, u32ECX, u32EDX)
762 || ASMIsAmdCpuEx(u32EBX, u32ECX, u32EDX)
763 || ASMIsViaCentaurCpuEx(u32EBX, u32ECX, u32EDX))
764 && ASMIsValidStdRange(uMaxLeaf))
765 {
766 uint32_t uDummy;
767 ASMCpuId(1, &uDummy, &u32EBX, &u32ECX, &u32EDX);
768 if ( (u32EDX & X86_CPUID_FEATURE_EDX_APIC)
769 && (u32EDX & X86_CPUID_FEATURE_EDX_MSR))
770 {
771 /*
772 * Safe to access the MSR. Read it and calc the BASE (a little complicated).
773 */
774 uint64_t u64ApicBase = ASMRdMsr(MSR_IA32_APICBASE);
775 uint64_t u64Mask = MSR_IA32_APICBASE_BASE_MIN;
776
777 /* see Intel Manual: Local APIC Status and Location: MAXPHYADDR default is bit 36 */
778 uint32_t uMaxExtLeaf;
779 ASMCpuId(0x80000000, &uMaxExtLeaf, &u32EBX, &u32ECX, &u32EDX);
780 if ( uMaxExtLeaf >= UINT32_C(0x80000008)
781 && ASMIsValidExtRange(uMaxExtLeaf))
782 {
783 uint32_t u32PhysBits;
784 ASMCpuId(0x80000008, &u32PhysBits, &u32EBX, &u32ECX, &u32EDX);
785 u32PhysBits &= 0xff;
786 u64Mask = ((UINT64_C(1) << u32PhysBits) - 1) & UINT64_C(0xfffffffffffff000);
787 }
788
789 AssertCompile(sizeof(g_aLApics[iCpu].PhysBase) == sizeof(u64ApicBase));
790 g_aLApics[iCpu].PhysBase = u64ApicBase & u64Mask;
791 g_aLApics[iCpu].fEnabled = RT_BOOL(u64ApicBase & MSR_IA32_APICBASE_EN);
792 g_aLApics[iCpu].fX2Apic = (u64ApicBase & (MSR_IA32_APICBASE_EXTD | MSR_IA32_APICBASE_EN))
793 == (MSR_IA32_APICBASE_EXTD | MSR_IA32_APICBASE_EN);
794 }
795 }
796}
797
798
799
800/**
801 * Per-CPU callback that verifies our APIC expectations.
802 *
803 * @param idCpu The identifier for the CPU the function is called on.
804 * @param pvUser1 Ignored.
805 * @param pvUser2 Ignored.
806 */
807static DECLCALLBACK(void) cpumR0MapLocalApicCpuChecker(RTCPUID idCpu, void *pvUser1, void *pvUser2)
808{
809 NOREF(pvUser1); NOREF(pvUser2);
810
811 int iCpu = RTMpCpuIdToSetIndex(idCpu);
812 AssertReturnVoid(iCpu >= 0 && (unsigned)iCpu < RT_ELEMENTS(g_aLApics));
813 if (!g_aLApics[iCpu].fEnabled)
814 return;
815
816 /*
817 * 0x0X 82489 external APIC
818 * 0x1X Local APIC
819 * 0x2X..0xFF reserved
820 */
821 uint32_t uApicVersion;
822 if (g_aLApics[iCpu].fX2Apic)
823 uApicVersion = ApicX2RegRead32(APIC_REG_VERSION);
824 else
825 uApicVersion = ApicRegRead(g_aLApics[iCpu].pv, APIC_REG_VERSION);
826 if ((APIC_REG_VERSION_GET_VER(uApicVersion) & 0xF0) == 0x10)
827 {
828 g_aLApics[iCpu].uVersion = uApicVersion;
829
830#if 0 /* enable if you need it. */
831 if (g_aLApics[iCpu].fX2Apic)
832 SUPR0Printf("CPUM: X2APIC %02u - ver %#010x, lint0=%#07x lint1=%#07x pc=%#07x thmr=%#07x cmci=%#07x\n",
833 iCpu, uApicVersion,
834 ApicX2RegRead32(APIC_REG_LVT_LINT0), ApicX2RegRead32(APIC_REG_LVT_LINT1),
835 ApicX2RegRead32(APIC_REG_LVT_PC), ApicX2RegRead32(APIC_REG_LVT_THMR),
836 ApicX2RegRead32(APIC_REG_LVT_CMCI));
837 else
838 {
839 SUPR0Printf("CPUM: APIC %02u at %RGp (mapped at %p) - ver %#010x, lint0=%#07x lint1=%#07x pc=%#07x thmr=%#07x cmci=%#07x\n",
840 iCpu, g_aLApics[iCpu].PhysBase, g_aLApics[iCpu].pv, uApicVersion,
841 ApicRegRead(g_aLApics[iCpu].pv, APIC_REG_LVT_LINT0), ApicRegRead(g_aLApics[iCpu].pv, APIC_REG_LVT_LINT1),
842 ApicRegRead(g_aLApics[iCpu].pv, APIC_REG_LVT_PC), ApicRegRead(g_aLApics[iCpu].pv, APIC_REG_LVT_THMR),
843 ApicRegRead(g_aLApics[iCpu].pv, APIC_REG_LVT_CMCI));
844 if (uApicVersion & 0x80000000)
845 {
846 uint32_t uExtFeatures = ApicRegRead(g_aLApics[iCpu].pv, 0x400);
847 uint32_t cEiLvt = (uExtFeatures >> 16) & 0xff;
848 SUPR0Printf("CPUM: APIC %02u: ExtSpace available. extfeat=%08x eilvt[0..3]=%08x %08x %08x %08x\n",
849 iCpu,
850 ApicRegRead(g_aLApics[iCpu].pv, 0x400),
851 cEiLvt >= 1 ? ApicRegRead(g_aLApics[iCpu].pv, 0x500) : 0,
852 cEiLvt >= 2 ? ApicRegRead(g_aLApics[iCpu].pv, 0x510) : 0,
853 cEiLvt >= 3 ? ApicRegRead(g_aLApics[iCpu].pv, 0x520) : 0,
854 cEiLvt >= 4 ? ApicRegRead(g_aLApics[iCpu].pv, 0x530) : 0);
855 }
856 }
857#endif
858 }
859 else
860 {
861 g_aLApics[iCpu].fEnabled = false;
862 g_aLApics[iCpu].fX2Apic = false;
863 SUPR0Printf("VBox/CPUM: Unsupported APIC version %#x (iCpu=%d)\n", uApicVersion, iCpu);
864 }
865}
866
867
868/**
869 * Map the MMIO page of each local APIC in the system.
870 */
871static int cpumR0MapLocalApics(void)
872{
873 /*
874 * Check that we'll always stay within the array bounds.
875 */
876 if (RTMpGetArraySize() > RT_ELEMENTS(g_aLApics))
877 {
878 LogRel(("CPUM: Too many real CPUs/cores/threads - %u, max %u\n", RTMpGetArraySize(), RT_ELEMENTS(g_aLApics)));
879 return VERR_TOO_MANY_CPUS;
880 }
881
882 /*
883 * Create mappings for all online CPUs we think have legacy APICs.
884 */
885 int rc = RTMpOnAll(cpumR0MapLocalApicCpuProber, NULL, NULL);
886
887 for (unsigned iCpu = 0; RT_SUCCESS(rc) && iCpu < RT_ELEMENTS(g_aLApics); iCpu++)
888 {
889 if (g_aLApics[iCpu].fEnabled && !g_aLApics[iCpu].fX2Apic)
890 {
891 rc = RTR0MemObjEnterPhys(&g_aLApics[iCpu].hMemObj, g_aLApics[iCpu].PhysBase,
892 PAGE_SIZE, RTMEM_CACHE_POLICY_MMIO);
893 if (RT_SUCCESS(rc))
894 {
895 rc = RTR0MemObjMapKernel(&g_aLApics[iCpu].hMapObj, g_aLApics[iCpu].hMemObj, (void *)-1,
896 PAGE_SIZE, RTMEM_PROT_READ | RTMEM_PROT_WRITE);
897 if (RT_SUCCESS(rc))
898 {
899 g_aLApics[iCpu].pv = RTR0MemObjAddress(g_aLApics[iCpu].hMapObj);
900 continue;
901 }
902 RTR0MemObjFree(g_aLApics[iCpu].hMemObj, true /* fFreeMappings */);
903 }
904 g_aLApics[iCpu].fEnabled = false;
905 }
906 g_aLApics[iCpu].pv = NULL;
907 }
908
909 /*
910 * Check the APICs.
911 */
912 if (RT_SUCCESS(rc))
913 rc = RTMpOnAll(cpumR0MapLocalApicCpuChecker, NULL, NULL);
914
915 if (RT_FAILURE(rc))
916 {
917 cpumR0UnmapLocalApics();
918 return rc;
919 }
920
921#ifdef LOG_ENABLED
922 /*
923 * Log the result (pretty useless, requires enabling CPUM in VBoxDrv
924 * and !VBOX_WITH_R0_LOGGING).
925 */
926 if (LogIsEnabled())
927 {
928 uint32_t cEnabled = 0;
929 uint32_t cX2Apics = 0;
930 for (unsigned iCpu = 0; iCpu < RT_ELEMENTS(g_aLApics); iCpu++)
931 if (g_aLApics[iCpu].fEnabled)
932 {
933 cEnabled++;
934 cX2Apics += g_aLApics[iCpu].fX2Apic;
935 }
936 Log(("CPUM: %u APICs, %u X2APICs\n", cEnabled, cX2Apics));
937 }
938#endif
939
940 return VINF_SUCCESS;
941}
942
943
944/**
945 * Unmap the Local APIC of all host CPUs.
946 */
947static void cpumR0UnmapLocalApics(void)
948{
949 for (unsigned iCpu = RT_ELEMENTS(g_aLApics); iCpu-- > 0;)
950 {
951 if (g_aLApics[iCpu].pv)
952 {
953 RTR0MemObjFree(g_aLApics[iCpu].hMapObj, true /* fFreeMappings */);
954 RTR0MemObjFree(g_aLApics[iCpu].hMemObj, true /* fFreeMappings */);
955 g_aLApics[iCpu].hMapObj = NIL_RTR0MEMOBJ;
956 g_aLApics[iCpu].hMemObj = NIL_RTR0MEMOBJ;
957 g_aLApics[iCpu].fEnabled = false;
958 g_aLApics[iCpu].fX2Apic = false;
959 g_aLApics[iCpu].pv = NULL;
960 }
961 }
962}
963
964
965/**
966 * Updates CPUMCPU::pvApicBase and CPUMCPU::fX2Apic prior to world switch.
967 *
968 * Writes the Local APIC mapping address of the current host CPU to CPUMCPU so
969 * the world switchers can access the APIC registers for the purpose of
970 * disabling and re-enabling the NMIs. Must be called with disabled preemption
971 * or disabled interrupts!
972 *
973 * @param pVCpu The cross context virtual CPU structure of the calling EMT.
974 * @param iHostCpuSet The CPU set index of the current host CPU.
975 */
976VMMR0_INT_DECL(void) CPUMR0SetLApic(PVMCPU pVCpu, uint32_t iHostCpuSet)
977{
978 Assert(iHostCpuSet <= RT_ELEMENTS(g_aLApics));
979 pVCpu->cpum.s.pvApicBase = g_aLApics[iHostCpuSet].pv;
980 pVCpu->cpum.s.fX2Apic = g_aLApics[iHostCpuSet].fX2Apic;
981// Log6(("CPUMR0SetLApic: pvApicBase=%p fX2Apic=%d\n", g_aLApics[idxCpu].pv, g_aLApics[idxCpu].fX2Apic));
982}
983
984#endif /* VBOX_WITH_VMMR0_DISABLE_LAPIC_NMI */
985
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