VirtualBox

source: vbox/trunk/src/VBox/VMM/VMMR0/CPUMR0.cpp@ 16102

Last change on this file since 16102 was 16102, checked in by vboxsync, 16 years ago

CPUMR0.cpp: VBOX_ENABLE_64_BITS_GUESTS is a HWACCM local macro, use VBOX_WITH_64_BITS_GUESTS instead. Fixes guest XMM8..15 and DRx0..3 corruption.

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1/* $Id: CPUMR0.cpp 16102 2009-01-20 21:42:11Z 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 /* 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;
175RTLogPrintf("setting CPUM_SYNC_FPU_STATE\n");
176 }
177 else
178#endif
179 {
180#ifndef CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE
181 uint64_t oldMsrEFERHost = 0;
182 uint32_t oldCR0 = ASMGetCR0();
183
184 /* Clear MSR_K6_EFER_FFXSR or else we'll be unable to save/restore the XMM state with fxsave/fxrstor. */
185 if (pVM->cpum.s.CPUFeaturesExt.edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR)
186 {
187 /** @todo Do we really need to read this every time?? The host could change this on the fly though.
188 * bird: what about starting by skipping the ASMWrMsr below if we didn't
189 * change anything? Ditto for the stuff in CPUMR0SaveGuestFPU. */
190 oldMsrEFERHost = ASMRdMsr(MSR_K6_EFER);
191 if (oldMsrEFERHost & MSR_K6_EFER_FFXSR)
192 {
193 ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost & ~MSR_K6_EFER_FFXSR);
194 pVCpu->cpum.s.fUseFlags |= CPUM_MANUAL_XMM_RESTORE;
195 }
196 }
197
198 /* If we sync the FPU/XMM state on-demand, then we can continue execution as if nothing has happened. */
199 int rc = CPUMHandleLazyFPU(pVM, pVCpu);
200 AssertRC(rc);
201 Assert(CPUMIsGuestFPUStateActive(pVCpu));
202
203 /* Restore EFER MSR */
204 if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
205 ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost);
206
207 /* CPUMHandleLazyFPU could have changed CR0; restore it. */
208 ASMSetCR0(oldCR0);
209
210#else /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
211
212 /*
213 * Save the FPU control word and MXCSR, so we can restore the state properly afterwards.
214 * We don't want the guest to be able to trigger floating point/SSE exceptions on the host.
215 */
216 pVCpu->cpum.s.Host.fpu.FCW = CPUMGetFCW();
217 if (pVM->cpum.s.CPUFeatures.edx.u1SSE)
218 pVCpu->cpum.s.Host.fpu.MXCSR = CPUMGetMXCSR();
219
220 cpumR0LoadFPU(pCtx);
221
222 /*
223 * The MSR_K6_EFER_FFXSR feature is AMD only so far, but check the cpuid just in case Intel adds it in the future.
224 *
225 * MSR_K6_EFER_FFXSR changes the behaviour of fxsave and fxrstore: the XMM state isn't saved/restored
226 */
227 if (pVM->cpum.s.CPUFeaturesExt.edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR)
228 {
229 /** @todo Do we really need to read this every time?? The host could change this on the fly though. */
230 uint64_t msrEFERHost = ASMRdMsr(MSR_K6_EFER);
231
232 if (msrEFERHost & MSR_K6_EFER_FFXSR)
233 {
234 /* fxrstor doesn't restore the XMM state! */
235 cpumR0LoadXMM(pCtx);
236 pVCpu->cpum.s.fUseFlags |= CPUM_MANUAL_XMM_RESTORE;
237 }
238 }
239#endif /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
240 }
241
242 pVCpu->cpum.s.fUseFlags |= CPUM_USED_FPU;
243 return VINF_SUCCESS;
244}
245
246
247/**
248 * Save guest FPU/XMM state
249 *
250 * @returns VBox status code.
251 * @param pVM VM handle.
252 * @param pVCpu VMCPU handle.
253 * @param pCtx CPU context
254 */
255VMMR0DECL(int) CPUMR0SaveGuestFPU(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx)
256{
257 Assert(pVM->cpum.s.CPUFeatures.edx.u1FXSR);
258 Assert(ASMGetCR4() & X86_CR4_OSFSXR);
259 AssertReturn((pVCpu->cpum.s.fUseFlags & CPUM_USED_FPU), VINF_SUCCESS);
260
261#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS) && !defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
262 if (CPUMIsGuestInLongModeEx(pCtx))
263 {
264if (!(pVCpu->cpum.s.fUseFlags & CPUM_SYNC_FPU_STATE))
265 RTLogPrintf("CPUMR0SaveGuestFPU: CPUM_SYNC_FPU_STATE is clear...\n");
266else RTLogPrintf("CPUMR0SaveGuestFPU: CPUM_SYNC_FPU_STATE is still set\n");
267 if (!(pVCpu->cpum.s.fUseFlags & CPUM_SYNC_FPU_STATE))
268 HWACCMR0SaveFPUState(pVM, pVCpu, pCtx);
269
270
271 cpumR0RestoreHostFPUState(&pVCpu->cpum.s);
272 }
273 else
274#endif
275 {
276#ifndef CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE
277 uint64_t oldMsrEFERHost = 0;
278
279 /* Clear MSR_K6_EFER_FFXSR or else we'll be unable to save/restore the XMM state with fxsave/fxrstor. */
280 if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
281 {
282 oldMsrEFERHost = ASMRdMsr(MSR_K6_EFER);
283 ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost & ~MSR_K6_EFER_FFXSR);
284 }
285 cpumR0SaveGuestRestoreHostFPUState(&pVCpu->cpum.s);
286
287 /* Restore EFER MSR */
288 if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
289 ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost | MSR_K6_EFER_FFXSR);
290
291#else /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
292 cpumR0SaveFPU(pCtx);
293 if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
294 {
295 /* fxsave doesn't save the XMM state! */
296 cpumR0SaveXMM(pCtx);
297 }
298
299 /*
300 * Restore the original FPU control word and MXCSR.
301 * We don't want the guest to be able to trigger floating point/SSE exceptions on the host.
302 */
303 cpumR0SetFCW(pVCpu->cpum.s.Host.fpu.FCW);
304 if (pVM->cpum.s.CPUFeatures.edx.u1SSE)
305 cpumR0SetMXCSR(pVCpu->cpum.s.Host.fpu.MXCSR);
306#endif /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
307 }
308
309 pVCpu->cpum.s.fUseFlags &= ~(CPUM_USED_FPU | CPUM_MANUAL_XMM_RESTORE);
310 return VINF_SUCCESS;
311}
312
313
314/**
315 * Save guest debug state
316 *
317 * @returns VBox status code.
318 * @param pVM VM handle.
319 * @param pVCpu VMCPU handle.
320 * @param pCtx CPU context
321 * @param fDR6 Include DR6 or not
322 */
323VMMR0DECL(int) CPUMR0SaveGuestDebugState(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx, bool fDR6)
324{
325 Assert(pVCpu->cpum.s.fUseFlags & CPUM_USE_DEBUG_REGS);
326
327 /* Save the guest's debug state. The caller is responsible for DR7. */
328#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS) && !defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
329 if (CPUMIsGuestInLongModeEx(pCtx))
330 {
331 if (!(pVCpu->cpum.s.fUseFlags & CPUM_SYNC_DEBUG_STATE))
332 {
333 uint64_t dr6 = pCtx->dr[6];
334
335 HWACCMR0SaveDebugState(pVM, pVCpu, pCtx);
336 if (!fDR6) /* dr6 was already up-to-date */
337 pCtx->dr[6] = dr6;
338 }
339 }
340 else
341#endif
342 {
343#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
344 cpumR0SaveDRx(&pCtx->dr[0]);
345#else
346 pCtx->dr[0] = ASMGetDR0();
347 pCtx->dr[1] = ASMGetDR1();
348 pCtx->dr[2] = ASMGetDR2();
349 pCtx->dr[3] = ASMGetDR3();
350#endif
351 if (fDR6)
352 pCtx->dr[6] = ASMGetDR6();
353 }
354
355 /*
356 * Restore the host's debug state. DR0-3, DR6 and only then DR7!
357 * DR7 contains 0x400 right now.
358 */
359#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
360 AssertCompile((uintptr_t)&pVCpu->cpum.s.Host.dr3 - (uintptr_t)&pVCpu->cpum.s.Host.dr0 == sizeof(uint64_t) * 3);
361 cpumR0LoadDRx(&pVCpu->cpum.s.Host.dr0);
362#else
363 ASMSetDR0(pVCpu->cpum.s.Host.dr0);
364 ASMSetDR1(pVCpu->cpum.s.Host.dr1);
365 ASMSetDR2(pVCpu->cpum.s.Host.dr2);
366 ASMSetDR3(pVCpu->cpum.s.Host.dr3);
367#endif
368 ASMSetDR6(pVCpu->cpum.s.Host.dr6);
369 ASMSetDR7(pVCpu->cpum.s.Host.dr7);
370
371 pVCpu->cpum.s.fUseFlags &= ~CPUM_USE_DEBUG_REGS;
372 return VINF_SUCCESS;
373}
374
375
376/**
377 * Lazily sync in the debug state
378 *
379 * @returns VBox status code.
380 * @param pVM VM handle.
381 * @param pVCpu VMCPU handle.
382 * @param pCtx CPU context
383 * @param fDR6 Include DR6 or not
384 */
385VMMR0DECL(int) CPUMR0LoadGuestDebugState(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx, bool fDR6)
386{
387 /* Save the host state. */
388#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
389 AssertCompile((uintptr_t)&pVCpu->cpum.s.Host.dr3 - (uintptr_t)&pVCpu->cpum.s.Host.dr0 == sizeof(uint64_t) * 3);
390 cpumR0SaveDRx(&pVCpu->cpum.s.Host.dr0);
391#else
392 pVCpu->cpum.s.Host.dr0 = ASMGetDR0();
393 pVCpu->cpum.s.Host.dr1 = ASMGetDR1();
394 pVCpu->cpum.s.Host.dr2 = ASMGetDR2();
395 pVCpu->cpum.s.Host.dr3 = ASMGetDR3();
396#endif
397 pVCpu->cpum.s.Host.dr6 = ASMGetDR6();
398 /** @todo dr7 might already have been changed to 0x400; don't care right now as it's harmless. */
399 pVCpu->cpum.s.Host.dr7 = ASMGetDR7();
400 /* Make sure DR7 is harmless or else we could trigger breakpoints when restoring dr0-3 (!) */
401 ASMSetDR7(X86_DR7_INIT_VAL);
402
403 /* Activate the guest state DR0-3; DR7 is left to the caller. */
404#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS) && !defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
405 if (CPUMIsGuestInLongModeEx(pCtx))
406 {
407 /* Restore the state on entry as we need to be in 64 bits mode to access the full state. */
408 pVCpu->cpum.s.fUseFlags |= CPUM_SYNC_DEBUG_STATE;
409 }
410 else
411#endif
412 {
413#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
414 cpumR0LoadDRx(&pCtx->dr[0]);
415#else
416 ASMSetDR0(pCtx->dr[0]);
417 ASMSetDR1(pCtx->dr[1]);
418 ASMSetDR2(pCtx->dr[2]);
419 ASMSetDR3(pCtx->dr[3]);
420#endif
421 if (fDR6)
422 ASMSetDR6(pCtx->dr[6]);
423 }
424
425 pVCpu->cpum.s.fUseFlags |= CPUM_USE_DEBUG_REGS;
426 return VINF_SUCCESS;
427}
428
429
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