CPUMR0.cpp@ 16106

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1	/* $Id: CPUMR0.cpp 16106 2009-01-20 22:35:20Z 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	*/
48	VMMR0DECL(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	*/
123	VMMR0DECL(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;
175	}
176	else
177	#endif
178	{
179	#ifndef CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE
180	uint64_t oldMsrEFERHost = 0;
181	uint32_t oldCR0 = ASMGetCR0();
182
183	/* Clear MSR_K6_EFER_FFXSR or else we'll be unable to save/restore the XMM state with fxsave/fxrstor. */
184	if (pVM->cpum.s.CPUFeaturesExt.edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR)
185	{
186	/** @todo Do we really need to read this every time?? The host could change this on the fly though.
187	* bird: what about starting by skipping the ASMWrMsr below if we didn't
188	* change anything? Ditto for the stuff in CPUMR0SaveGuestFPU. */
189	oldMsrEFERHost = ASMRdMsr(MSR_K6_EFER);
190	if (oldMsrEFERHost & MSR_K6_EFER_FFXSR)
191	{
192	ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost & ~MSR_K6_EFER_FFXSR);
193	pVCpu->cpum.s.fUseFlags \|= CPUM_MANUAL_XMM_RESTORE;
194	}
195	}
196
197	/* If we sync the FPU/XMM state on-demand, then we can continue execution as if nothing has happened. */
198	int rc = CPUMHandleLazyFPU(pVM, pVCpu);
199	AssertRC(rc);
200	Assert(CPUMIsGuestFPUStateActive(pVCpu));
201
202	/* Restore EFER MSR */
203	if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
204	ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost);
205
206	/* CPUMHandleLazyFPU could have changed CR0; restore it. */
207	ASMSetCR0(oldCR0);
208
209	#else /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
210
211	/*
212	* Save the FPU control word and MXCSR, so we can restore the state properly afterwards.
213	* We don't want the guest to be able to trigger floating point/SSE exceptions on the host.
214	*/
215	pVCpu->cpum.s.Host.fpu.FCW = CPUMGetFCW();
216	if (pVM->cpum.s.CPUFeatures.edx.u1SSE)
217	pVCpu->cpum.s.Host.fpu.MXCSR = CPUMGetMXCSR();
218
219	cpumR0LoadFPU(pCtx);
220
221	/*
222	* The MSR_K6_EFER_FFXSR feature is AMD only so far, but check the cpuid just in case Intel adds it in the future.
223	*
224	* MSR_K6_EFER_FFXSR changes the behaviour of fxsave and fxrstore: the XMM state isn't saved/restored
225	*/
226	if (pVM->cpum.s.CPUFeaturesExt.edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR)
227	{
228	/** @todo Do we really need to read this every time?? The host could change this on the fly though. */
229	uint64_t msrEFERHost = ASMRdMsr(MSR_K6_EFER);
230
231	if (msrEFERHost & MSR_K6_EFER_FFXSR)
232	{
233	/* fxrstor doesn't restore the XMM state! */
234	cpumR0LoadXMM(pCtx);
235	pVCpu->cpum.s.fUseFlags \|= CPUM_MANUAL_XMM_RESTORE;
236	}
237	}
238	#endif /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
239	}
240
241	pVCpu->cpum.s.fUseFlags \|= CPUM_USED_FPU;
242	return VINF_SUCCESS;
243	}
244
245
246	/**
247	* Save guest FPU/XMM state
248	*
249	* @returns VBox status code.
250	* @param pVM VM handle.
251	* @param pVCpu VMCPU handle.
252	* @param pCtx CPU context
253	*/
254	VMMR0DECL(int) CPUMR0SaveGuestFPU(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx)
255	{
256	Assert(pVM->cpum.s.CPUFeatures.edx.u1FXSR);
257	Assert(ASMGetCR4() & X86_CR4_OSFSXR);
258	AssertReturn((pVCpu->cpum.s.fUseFlags & CPUM_USED_FPU), VINF_SUCCESS);
259
260	#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS) && !defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
261	if (CPUMIsGuestInLongModeEx(pCtx))
262	{
263	if (!(pVCpu->cpum.s.fUseFlags & CPUM_SYNC_FPU_STATE))
264	HWACCMR0SaveFPUState(pVM, pVCpu, pCtx);
265	cpumR0RestoreHostFPUState(&pVCpu->cpum.s);
266	}
267	else
268	#endif
269	{
270	#ifndef CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE
271	uint64_t oldMsrEFERHost = 0;
272
273	/* Clear MSR_K6_EFER_FFXSR or else we'll be unable to save/restore the XMM state with fxsave/fxrstor. */
274	if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
275	{
276	oldMsrEFERHost = ASMRdMsr(MSR_K6_EFER);
277	ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost & ~MSR_K6_EFER_FFXSR);
278	}
279	cpumR0SaveGuestRestoreHostFPUState(&pVCpu->cpum.s);
280
281	/* Restore EFER MSR */
282	if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
283	ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost \| MSR_K6_EFER_FFXSR);
284
285	#else /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
286	cpumR0SaveFPU(pCtx);
287	if (pVCpu->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
288	{
289	/* fxsave doesn't save the XMM state! */
290	cpumR0SaveXMM(pCtx);
291	}
292
293	/*
294	* Restore the original FPU control word and MXCSR.
295	* We don't want the guest to be able to trigger floating point/SSE exceptions on the host.
296	*/
297	cpumR0SetFCW(pVCpu->cpum.s.Host.fpu.FCW);
298	if (pVM->cpum.s.CPUFeatures.edx.u1SSE)
299	cpumR0SetMXCSR(pVCpu->cpum.s.Host.fpu.MXCSR);
300	#endif /* CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE */
301	}
302
303	pVCpu->cpum.s.fUseFlags &= ~(CPUM_USED_FPU \| CPUM_MANUAL_XMM_RESTORE);
304	return VINF_SUCCESS;
305	}
306
307
308	/**
309	* Save guest debug state
310	*
311	* @returns VBox status code.
312	* @param pVM VM handle.
313	* @param pVCpu VMCPU handle.
314	* @param pCtx CPU context
315	* @param fDR6 Include DR6 or not
316	*/
317	VMMR0DECL(int) CPUMR0SaveGuestDebugState(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx, bool fDR6)
318	{
319	Assert(pVCpu->cpum.s.fUseFlags & CPUM_USE_DEBUG_REGS);
320
321	/* Save the guest's debug state. The caller is responsible for DR7. */
322	#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS) && !defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
323	if (CPUMIsGuestInLongModeEx(pCtx))
324	{
325	if (!(pVCpu->cpum.s.fUseFlags & CPUM_SYNC_DEBUG_STATE))
326	{
327	uint64_t dr6 = pCtx->dr[6];
328
329	HWACCMR0SaveDebugState(pVM, pVCpu, pCtx);
330	if (!fDR6) /* dr6 was already up-to-date */
331	pCtx->dr[6] = dr6;
332	}
333	}
334	else
335	#endif
336	{
337	#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
338	cpumR0SaveDRx(&pCtx->dr[0]);
339	#else
340	pCtx->dr[0] = ASMGetDR0();
341	pCtx->dr[1] = ASMGetDR1();
342	pCtx->dr[2] = ASMGetDR2();
343	pCtx->dr[3] = ASMGetDR3();
344	#endif
345	if (fDR6)
346	pCtx->dr[6] = ASMGetDR6();
347	}
348
349	/*
350	* Restore the host's debug state. DR0-3, DR6 and only then DR7!
351	* DR7 contains 0x400 right now.
352	*/
353	#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
354	AssertCompile((uintptr_t)&pVCpu->cpum.s.Host.dr3 - (uintptr_t)&pVCpu->cpum.s.Host.dr0 == sizeof(uint64_t) * 3);
355	cpumR0LoadDRx(&pVCpu->cpum.s.Host.dr0);
356	#else
357	ASMSetDR0(pVCpu->cpum.s.Host.dr0);
358	ASMSetDR1(pVCpu->cpum.s.Host.dr1);
359	ASMSetDR2(pVCpu->cpum.s.Host.dr2);
360	ASMSetDR3(pVCpu->cpum.s.Host.dr3);
361	#endif
362	ASMSetDR6(pVCpu->cpum.s.Host.dr6);
363	ASMSetDR7(pVCpu->cpum.s.Host.dr7);
364
365	pVCpu->cpum.s.fUseFlags &= ~CPUM_USE_DEBUG_REGS;
366	return VINF_SUCCESS;
367	}
368
369
370	/**
371	* Lazily sync in the debug state
372	*
373	* @returns VBox status code.
374	* @param pVM VM handle.
375	* @param pVCpu VMCPU handle.
376	* @param pCtx CPU context
377	* @param fDR6 Include DR6 or not
378	*/
379	VMMR0DECL(int) CPUMR0LoadGuestDebugState(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx, bool fDR6)
380	{
381	/* Save the host state. */
382	#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
383	AssertCompile((uintptr_t)&pVCpu->cpum.s.Host.dr3 - (uintptr_t)&pVCpu->cpum.s.Host.dr0 == sizeof(uint64_t) * 3);
384	cpumR0SaveDRx(&pVCpu->cpum.s.Host.dr0);
385	#else
386	pVCpu->cpum.s.Host.dr0 = ASMGetDR0();
387	pVCpu->cpum.s.Host.dr1 = ASMGetDR1();
388	pVCpu->cpum.s.Host.dr2 = ASMGetDR2();
389	pVCpu->cpum.s.Host.dr3 = ASMGetDR3();
390	#endif
391	pVCpu->cpum.s.Host.dr6 = ASMGetDR6();
392	/** @todo dr7 might already have been changed to 0x400; don't care right now as it's harmless. */
393	pVCpu->cpum.s.Host.dr7 = ASMGetDR7();
394	/* Make sure DR7 is harmless or else we could trigger breakpoints when restoring dr0-3 (!) */
395	ASMSetDR7(X86_DR7_INIT_VAL);
396
397	/* Activate the guest state DR0-3; DR7 is left to the caller. */
398	#if HC_ARCH_BITS == 32 && defined(VBOX_WITH_64_BITS_GUESTS) && !defined(VBOX_WITH_HYBRID_32BIT_KERNEL)
399	if (CPUMIsGuestInLongModeEx(pCtx))
400	{
401	/* Restore the state on entry as we need to be in 64 bits mode to access the full state. */
402	pVCpu->cpum.s.fUseFlags \|= CPUM_SYNC_DEBUG_STATE;
403	}
404	else
405	#endif
406	{
407	#ifdef VBOX_WITH_HYBRID_32BIT_KERNEL
408	cpumR0LoadDRx(&pCtx->dr[0]);
409	#else
410	ASMSetDR0(pCtx->dr[0]);
411	ASMSetDR1(pCtx->dr[1]);
412	ASMSetDR2(pCtx->dr[2]);
413	ASMSetDR3(pCtx->dr[3]);
414	#endif
415	if (fDR6)
416	ASMSetDR6(pCtx->dr[6]);
417	}
418
419	pVCpu->cpum.s.fUseFlags \|= CPUM_USE_DEBUG_REGS;
420	return VINF_SUCCESS;
421	}
422
423

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source: vbox/trunk/src/VBox/VMM/VMMR0/CPUMR0.cpp@ 16106

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