VirtualBox

source: vbox/trunk/src/VBox/VMM/VMMR0/CPUMR0.cpp@ 16109

Last change on this file since 16109 was 16109, checked in by vboxsync, 16 years ago

CPUMR0: Don't forget to set CPUM_USED_FPU_SINCE_REM.

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1/* $Id: CPUMR0.cpp 16109 2009-01-21 01:35:14Z vboxsync $ */
2/** @file
3 * CPUM - Host Context Ring 0.
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_CPUM
27#include <VBox/cpum.h>
28#include "CPUMInternal.h"
29#include <VBox/vm.h>
30#include <VBox/x86.h>
31#include <VBox/err.h>
32#include <VBox/log.h>
33#include <VBox/hwaccm.h>
34#include <iprt/assert.h>
35#include <iprt/asm.h>
36
37
38
39/**
40 * Does Ring-0 CPUM initialization.
41 *
42 * This is mainly to check that the Host CPU mode is compatible
43 * with VBox.
44 *
45 * @returns VBox status code.
46 * @param pVM The VM to operate on.
47 */
48VMMR0DECL(int) CPUMR0Init(PVM pVM)
49{
50 LogFlow(("CPUMR0Init: %p\n", pVM));
51
52 /*
53 * Check CR0 & CR4 flags.
54 */
55 uint32_t u32CR0 = ASMGetCR0();
56 if ((u32CR0 & (X86_CR0_PE | X86_CR0_PG)) != (X86_CR0_PE | X86_CR0_PG)) /* a bit paranoid perhaps.. */
57 {
58 Log(("CPUMR0Init: PE or PG not set. cr0=%#x\n", u32CR0));
59 return VERR_UNSUPPORTED_CPU_MODE;
60 }
61
62 /*
63 * Check for sysenter if it's used.
64 */
65 if (ASMHasCpuId())
66 {
67 uint32_t u32CpuVersion;
68 uint32_t u32Dummy;
69 uint32_t u32Features;
70 ASMCpuId(1, &u32CpuVersion, &u32Dummy, &u32Dummy, &u32Features);
71 uint32_t u32Family = u32CpuVersion >> 8;
72 uint32_t u32Model = (u32CpuVersion >> 4) & 0xF;
73 uint32_t u32Stepping = u32CpuVersion & 0xF;
74
75 /*
76 * Intel docs claim you should test both the flag and family, model & stepping.
77 * Some Pentium Pro cpus have the SEP cpuid flag set, but don't support it.
78 */
79 if ( (u32Features & X86_CPUID_FEATURE_EDX_SEP)
80 && !(u32Family == 6 && u32Model < 3 && u32Stepping < 3))
81 {
82 /*
83 * Read the MSR and see if it's in use or not.
84 */
85 uint32_t u32 = ASMRdMsr_Low(MSR_IA32_SYSENTER_CS);
86 if (u32)
87 {
88 for (unsigned i=0;i<pVM->cCPUs;i++)
89 pVM->aCpus[i].cpum.s.fUseFlags |= CPUM_USE_SYSENTER;
90
91 Log(("CPUMR0Init: host uses sysenter cs=%08x%08x\n", ASMRdMsr_High(MSR_IA32_SYSENTER_CS), u32));
92 }
93 }
94
95 /** @todo check for AMD and syscall!!!!!! */
96 }
97
98
99 /*
100 * Check if debug registers are armed.
101 * This ASSUMES that DR7.GD is not set, or that it's handled transparently!
102 */
103 uint32_t u32DR7 = ASMGetDR7();
104 if (u32DR7 & X86_DR7_ENABLED_MASK)
105 {
106 for (unsigned i=0;i<pVM->cCPUs;i++)
107 pVM->aCpus[i].cpum.s.fUseFlags |= CPUM_USE_DEBUG_REGS_HOST;
108 Log(("CPUMR0Init: host uses debug registers (dr7=%x)\n", u32DR7));
109 }
110
111 return VINF_SUCCESS;
112}
113
114
115/**
116 * Lazily sync in the FPU/XMM state
117 *
118 * @returns VBox status code.
119 * @param pVM VM handle.
120 * @param pVCpu VMCPU handle.
121 * @param pCtx CPU context
122 */
123VMMR0DECL(int) CPUMR0LoadGuestFPU(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx)
124{
125 Assert(pVM->cpum.s.CPUFeatures.edx.u1FXSR);
126 Assert(ASMGetCR4() & X86_CR4_OSFSXR);
127
128 /* If the FPU state has already been loaded, then it's a guest trap. */
129 if (pVCpu->cpum.s.fUseFlags & CPUM_USED_FPU)
130 {
131 Assert( ((pCtx->cr0 & (X86_CR0_MP | X86_CR0_EM | X86_CR0_TS)) == (X86_CR0_MP | X86_CR0_EM | X86_CR0_TS))
132 || ((pCtx->cr0 & (X86_CR0_MP | X86_CR0_EM | X86_CR0_TS)) == (X86_CR0_MP | X86_CR0_TS)));
133 return VINF_EM_RAW_GUEST_TRAP;
134 }
135
136 /*
137 * There are two basic actions:
138 * 1. Save host fpu and restore guest fpu.
139 * 2. Generate guest trap.
140 *
141 * When entering the hypervisor we'll always enable MP (for proper wait
142 * trapping) and TS (for intercepting all fpu/mmx/sse stuff). The EM flag
143 * is taken from the guest OS in order to get proper SSE handling.
144 *
145 *
146 * Actions taken depending on the guest CR0 flags:
147 *
148 * 3 2 1
149 * TS | EM | MP | FPUInstr | WAIT :: VMM Action
150 * ------------------------------------------------------------------------
151 * 0 | 0 | 0 | Exec | Exec :: Clear TS & MP, Save HC, Load GC.
152 * 0 | 0 | 1 | Exec | Exec :: Clear TS, Save HC, Load GC.
153 * 0 | 1 | 0 | #NM | Exec :: Clear TS & MP, Save HC, Load GC.
154 * 0 | 1 | 1 | #NM | Exec :: Clear TS, Save HC, Load GC.
155 * 1 | 0 | 0 | #NM | Exec :: Clear MP, Save HC, Load GC. (EM is already cleared.)
156 * 1 | 0 | 1 | #NM | #NM :: Go to guest taking trap there.
157 * 1 | 1 | 0 | #NM | Exec :: Clear MP, Save HC, Load GC. (EM is already set.)
158 * 1 | 1 | 1 | #NM | #NM :: Go to guest taking trap there.
159 */
160
161 switch (pCtx->cr0 & (X86_CR0_MP | X86_CR0_EM | X86_CR0_TS))
162 {
163 case X86_CR0_MP | X86_CR0_TS:
164 case X86_CR0_MP | X86_CR0_EM | X86_CR0_TS:
165 return VINF_EM_RAW_GUEST_TRAP;
166 default:
167 break;
168 }
169
170#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS) && !defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
171 if (CPUMIsGuestInLongModeEx(pCtx))
172 {
173 /* Save/Restore the state on entry as we need to be in 64 bits mode to access the full state. */
174 pVCpu->cpum.s.fUseFlags |= CPUM_SYNC_FPU_STATE | CPUM_USED_FPU;
175 /** @todo who is saving the host state?? */
176 }
177 else
178#endif
179 {
180#ifndef CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE
181# ifdef VBOX_WITH_HYBRID_32BIT_KERNEL /** @todo remove the #else here and move cpumHandleLazyFPUAsm back to VMMGC after branching out 2.1. */
182 /* Clear MSR_K6_EFER_FFXSR or else we'll be unable to save/restore the XMM state with fxsave/fxrstor. */
183 uint64_t SavedEFER = 0;
184 if (pVM->cpum.s.CPUFeaturesExt.edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR)
185 {
186 SavedEFER = ASMRdMsr(MSR_K6_EFER);
187 if (SavedEFER & MSR_K6_EFER_FFXSR)
188 {
189 ASMWrMsr(MSR_K6_EFER, SavedEFER & ~MSR_K6_EFER_FFXSR);
190 pVCpu->cpum.s.fUseFlags |= CPUM_MANUAL_XMM_RESTORE;
191 }
192 }
193
194 /* Do the job and record that we've switched FPU state. */
195 cpumR0SaveHostRestoreGuestFPUState(&pVCpu->cpum.s);
196 pVCpu->cpum.s.fUseFlags |= CPUM_USED_FPU;
197
198 /* Restore EFER. */
199 if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
200 ASMWrMsr(MSR_K6_EFER, SavedEFER);
201
202# else
203 uint64_t oldMsrEFERHost = 0;
204 uint32_t oldCR0 = ASMGetCR0();
205
206 /* Clear MSR_K6_EFER_FFXSR or else we'll be unable to save/restore the XMM state with fxsave/fxrstor. */
207 if (pVM->cpum.s.CPUFeaturesExt.edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR)
208 {
209 /** @todo Do we really need to read this every time?? The host could change this on the fly though.
210 * bird: what about starting by skipping the ASMWrMsr below if we didn't
211 * change anything? Ditto for the stuff in CPUMR0SaveGuestFPU. */
212 oldMsrEFERHost = ASMRdMsr(MSR_K6_EFER);
213 if (oldMsrEFERHost & MSR_K6_EFER_FFXSR)
214 {
215 ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost & ~MSR_K6_EFER_FFXSR);
216 pVCpu->cpum.s.fUseFlags |= CPUM_MANUAL_XMM_RESTORE;
217 }
218 }
219
220 /* If we sync the FPU/XMM state on-demand, then we can continue execution as if nothing has happened. */
221 int rc = CPUMHandleLazyFPU(pVM, pVCpu);
222 AssertRC(rc);
223 Assert(CPUMIsGuestFPUStateActive(pVCpu));
224
225 /* Restore EFER MSR */
226 if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
227 ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost);
228
229 /* CPUMHandleLazyFPU could have changed CR0; restore it. */
230 ASMSetCR0(oldCR0);
231# endif
232
233#else /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
234
235 /*
236 * Save the FPU control word and MXCSR, so we can restore the state properly afterwards.
237 * We don't want the guest to be able to trigger floating point/SSE exceptions on the host.
238 */
239 pVCpu->cpum.s.Host.fpu.FCW = CPUMGetFCW();
240 if (pVM->cpum.s.CPUFeatures.edx.u1SSE)
241 pVCpu->cpum.s.Host.fpu.MXCSR = CPUMGetMXCSR();
242
243 cpumR0LoadFPU(pCtx);
244
245 /*
246 * The MSR_K6_EFER_FFXSR feature is AMD only so far, but check the cpuid just in case Intel adds it in the future.
247 *
248 * MSR_K6_EFER_FFXSR changes the behaviour of fxsave and fxrstore: the XMM state isn't saved/restored
249 */
250 if (pVM->cpum.s.CPUFeaturesExt.edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR)
251 {
252 /** @todo Do we really need to read this every time?? The host could change this on the fly though. */
253 uint64_t msrEFERHost = ASMRdMsr(MSR_K6_EFER);
254
255 if (msrEFERHost & MSR_K6_EFER_FFXSR)
256 {
257 /* fxrstor doesn't restore the XMM state! */
258 cpumR0LoadXMM(pCtx);
259 pVCpu->cpum.s.fUseFlags |= CPUM_MANUAL_XMM_RESTORE;
260 }
261 }
262
263#endif /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
264 }
265
266 pVCpu->cpum.s.fUseFlags |= CPUM_USED_FPU | CPUM_USED_FPU_SINCE_REM; /** @todo clean up, this is done above by the ASM worker. */
267 return VINF_SUCCESS;
268}
269
270
271/**
272 * Save guest FPU/XMM state
273 *
274 * @returns VBox status code.
275 * @param pVM VM handle.
276 * @param pVCpu VMCPU handle.
277 * @param pCtx CPU context
278 */
279VMMR0DECL(int) CPUMR0SaveGuestFPU(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx)
280{
281 Assert(pVM->cpum.s.CPUFeatures.edx.u1FXSR);
282 Assert(ASMGetCR4() & X86_CR4_OSFSXR);
283 AssertReturn((pVCpu->cpum.s.fUseFlags & CPUM_USED_FPU), VINF_SUCCESS);
284
285#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS) && !defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
286 if (CPUMIsGuestInLongModeEx(pCtx))
287 {
288 if (!(pVCpu->cpum.s.fUseFlags & CPUM_SYNC_FPU_STATE))
289 HWACCMR0SaveFPUState(pVM, pVCpu, pCtx);
290 cpumR0RestoreHostFPUState(&pVCpu->cpum.s);
291 }
292 else
293#endif
294 {
295#ifndef CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE
296 uint64_t oldMsrEFERHost = 0;
297
298 /* Clear MSR_K6_EFER_FFXSR or else we'll be unable to save/restore the XMM state with fxsave/fxrstor. */
299 if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
300 {
301 oldMsrEFERHost = ASMRdMsr(MSR_K6_EFER);
302 ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost & ~MSR_K6_EFER_FFXSR);
303 }
304 cpumR0SaveGuestRestoreHostFPUState(&pVCpu->cpum.s);
305
306 /* Restore EFER MSR */
307 if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
308 ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost | MSR_K6_EFER_FFXSR);
309
310#else /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
311 cpumR0SaveFPU(pCtx);
312 if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
313 {
314 /* fxsave doesn't save the XMM state! */
315 cpumR0SaveXMM(pCtx);
316 }
317
318 /*
319 * Restore the original FPU control word and MXCSR.
320 * We don't want the guest to be able to trigger floating point/SSE exceptions on the host.
321 */
322 cpumR0SetFCW(pVCpu->cpum.s.Host.fpu.FCW);
323 if (pVM->cpum.s.CPUFeatures.edx.u1SSE)
324 cpumR0SetMXCSR(pVCpu->cpum.s.Host.fpu.MXCSR);
325#endif /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
326 }
327
328 pVCpu->cpum.s.fUseFlags &= ~(CPUM_USED_FPU | CPUM_MANUAL_XMM_RESTORE);
329 return VINF_SUCCESS;
330}
331
332
333/**
334 * Save guest debug state
335 *
336 * @returns VBox status code.
337 * @param pVM VM handle.
338 * @param pVCpu VMCPU handle.
339 * @param pCtx CPU context
340 * @param fDR6 Include DR6 or not
341 */
342VMMR0DECL(int) CPUMR0SaveGuestDebugState(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx, bool fDR6)
343{
344 Assert(pVCpu->cpum.s.fUseFlags & CPUM_USE_DEBUG_REGS);
345
346 /* Save the guest's debug state. The caller is responsible for DR7. */
347#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS) && !defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
348 if (CPUMIsGuestInLongModeEx(pCtx))
349 {
350 if (!(pVCpu->cpum.s.fUseFlags & CPUM_SYNC_DEBUG_STATE))
351 {
352 uint64_t dr6 = pCtx->dr[6];
353
354 HWACCMR0SaveDebugState(pVM, pVCpu, pCtx);
355 if (!fDR6) /* dr6 was already up-to-date */
356 pCtx->dr[6] = dr6;
357 }
358 }
359 else
360#endif
361 {
362#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
363 cpumR0SaveDRx(&pCtx->dr[0]);
364#else
365 pCtx->dr[0] = ASMGetDR0();
366 pCtx->dr[1] = ASMGetDR1();
367 pCtx->dr[2] = ASMGetDR2();
368 pCtx->dr[3] = ASMGetDR3();
369#endif
370 if (fDR6)
371 pCtx->dr[6] = ASMGetDR6();
372 }
373
374 /*
375 * Restore the host's debug state. DR0-3, DR6 and only then DR7!
376 * DR7 contains 0x400 right now.
377 */
378#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
379 AssertCompile((uintptr_t)&pVCpu->cpum.s.Host.dr3 - (uintptr_t)&pVCpu->cpum.s.Host.dr0 == sizeof(uint64_t) * 3);
380 cpumR0LoadDRx(&pVCpu->cpum.s.Host.dr0);
381#else
382 ASMSetDR0(pVCpu->cpum.s.Host.dr0);
383 ASMSetDR1(pVCpu->cpum.s.Host.dr1);
384 ASMSetDR2(pVCpu->cpum.s.Host.dr2);
385 ASMSetDR3(pVCpu->cpum.s.Host.dr3);
386#endif
387 ASMSetDR6(pVCpu->cpum.s.Host.dr6);
388 ASMSetDR7(pVCpu->cpum.s.Host.dr7);
389
390 pVCpu->cpum.s.fUseFlags &= ~CPUM_USE_DEBUG_REGS;
391 return VINF_SUCCESS;
392}
393
394
395/**
396 * Lazily sync in the debug state
397 *
398 * @returns VBox status code.
399 * @param pVM VM handle.
400 * @param pVCpu VMCPU handle.
401 * @param pCtx CPU context
402 * @param fDR6 Include DR6 or not
403 */
404VMMR0DECL(int) CPUMR0LoadGuestDebugState(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx, bool fDR6)
405{
406 /* Save the host state. */
407#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
408 AssertCompile((uintptr_t)&pVCpu->cpum.s.Host.dr3 - (uintptr_t)&pVCpu->cpum.s.Host.dr0 == sizeof(uint64_t) * 3);
409 cpumR0SaveDRx(&pVCpu->cpum.s.Host.dr0);
410#else
411 pVCpu->cpum.s.Host.dr0 = ASMGetDR0();
412 pVCpu->cpum.s.Host.dr1 = ASMGetDR1();
413 pVCpu->cpum.s.Host.dr2 = ASMGetDR2();
414 pVCpu->cpum.s.Host.dr3 = ASMGetDR3();
415#endif
416 pVCpu->cpum.s.Host.dr6 = ASMGetDR6();
417 /** @todo dr7 might already have been changed to 0x400; don't care right now as it's harmless. */
418 pVCpu->cpum.s.Host.dr7 = ASMGetDR7();
419 /* Make sure DR7 is harmless or else we could trigger breakpoints when restoring dr0-3 (!) */
420 ASMSetDR7(X86_DR7_INIT_VAL);
421
422 /* Activate the guest state DR0-3; DR7 is left to the caller. */
423#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS) && !defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
424 if (CPUMIsGuestInLongModeEx(pCtx))
425 {
426 /* Restore the state on entry as we need to be in 64 bits mode to access the full state. */
427 pVCpu->cpum.s.fUseFlags |= CPUM_SYNC_DEBUG_STATE;
428 }
429 else
430#endif
431 {
432#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
433 cpumR0LoadDRx(&pCtx->dr[0]);
434#else
435 ASMSetDR0(pCtx->dr[0]);
436 ASMSetDR1(pCtx->dr[1]);
437 ASMSetDR2(pCtx->dr[2]);
438 ASMSetDR3(pCtx->dr[3]);
439#endif
440 if (fDR6)
441 ASMSetDR6(pCtx->dr[6]);
442 }
443
444 pVCpu->cpum.s.fUseFlags |= CPUM_USE_DEBUG_REGS;
445 return VINF_SUCCESS;
446}
447
448
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