1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
|
/** @file
* GCM - Guest Compatibility Manager.
*/
/*
* Copyright (C) 2022-2023 Oracle and/or its affiliates.
*
* This file is part of VirtualBox base platform packages, as
* available from https://www.virtualbox.org.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, in version 3 of the
* License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses>.
*
* SPDX-License-Identifier: GPL-3.0-only
*/
/** @page pg_gcm GCM - The Guest Compatibility Manager
*
* The Guest Compatibility Manager provides run-time compatibility fixes
* for certain known guest bugs.
*
* @see grp_gcm
*
*
* @section sec_gcm_fixer Fixers
*
* A GCM fixer implements a collection of run-time helpers/patches suitable for
* a specific guest type. Several fixers can be active at the same time; for
* example OS/2 or Windows 9x need their own fixers, but can also runs DOS
* applications which need DOS-specific fixers.
*
* The concept of fixers exists to reduce the number of false positives to a
* minimum. Heuristics are used to decide whether a particular fix should be
* applied or not; restricting the number of applicable fixes minimizes the
* chance that a fix could be misapplied.
*
* The fixers are invisible to a guest. A common problem is division by zero
* caused by a software timing loop which cannot deal with fast CPUs (where
* "fast" very much depends on the era when the software was written). A fixer
* intercepts division by zero, recognizes known register contents and code
* sequence, modifies one or more registers to avoid a divide error, and
* restarts the instruction.
*
* It is not expected that the set of active fixers would be changed during
* the lifetime of the VM.
*/
/*********************************************************************************************************************************
* Header Files *
*********************************************************************************************************************************/
#define LOG_GROUP LOG_GROUP_GIM
#include <VBox/vmm/gcm.h>
#include <VBox/vmm/hm.h>
#include <VBox/vmm/ssm.h>
#include <VBox/vmm/pdmdev.h>
#include "GCMInternal.h"
#include <VBox/vmm/vm.h>
#include <VBox/log.h>
#include <iprt/err.h>
#include <iprt/semaphore.h>
#include <iprt/string.h>
/*********************************************************************************************************************************
* Internal Functions *
*********************************************************************************************************************************/
static FNSSMINTSAVEEXEC gcmR3Save;
static FNSSMINTLOADEXEC gcmR3Load;
/**
* Initializes the GCM.
*
* @returns VBox status code.
* @param pVM The cross context VM structure.
*/
VMMR3_INT_DECL(int) GCMR3Init(PVM pVM)
{
LogFlow(("GCMR3Init\n"));
/*
* Assert alignment and sizes.
*/
AssertCompile(sizeof(pVM->gcm.s) <= sizeof(pVM->gcm.padding));
/*
* Register the saved state data unit.
*/
int rc = SSMR3RegisterInternal(pVM, "GCM", 0 /* uInstance */, GCM_SAVED_STATE_VERSION, sizeof(GCM),
NULL /* pfnLivePrep */, NULL /* pfnLiveExec */, NULL /* pfnLiveVote*/,
NULL /* pfnSavePrep */, gcmR3Save, NULL /* pfnSaveDone */,
NULL /* pfnLoadPrep */, gcmR3Load, NULL /* pfnLoadDone */);
if (RT_FAILURE(rc))
return rc;
/*
* Read configuration.
*/
PCFGMNODE pCfgNode = CFGMR3GetChild(CFGMR3GetRoot(pVM), "GCM/");
/*
* Validate the GCM settings.
*/
rc = CFGMR3ValidateConfig(pCfgNode, "/GCM/", /* pszNode */
"FixerSet", /* pszValidValues */
"", /* pszValidNodes */
"GCM", /* pszWho */
0); /* uInstance */
if (RT_FAILURE(rc))
return rc;
#if 1
/** @cfgm{/GCM/FixerSet, uint32_t, 0}
* The set (bit mask) of enabled fixers. See GCMFIXERID.
*/
uint32_t u32FixerIds;
rc = CFGMR3QueryU32Def(pCfgNode, "FixerSet", &u32FixerIds, 0);
AssertRCReturn(rc, rc);
/* Check for unknown bits. */
uint32_t u32BadBits = u32FixerIds & ~(GCMFIXER_DBZ_DOS | GCMFIXER_DBZ_OS2 | GCMFIXER_DBZ_WIN9X);
if (u32BadBits)
{
rc = VMR3SetError(pVM->pUVM, VERR_CFGM_CONFIG_UNKNOWN_VALUE, RT_SRC_POS, "Unsupported GCM fixer bits (%#x) set.", u32BadBits);
}
else
{
pVM->gcm.s.enmFixerIds = u32FixerIds;
}
#else
pVM->gcm.s.enmFixerIds = GCMFIXER_DBZ_OS2 | GCMFIXER_DBZ_DOS | GCMFIXER_DBZ_WIN9X;
#endif
LogRel(("GCM: Initialized (fixer bits: %#x)\n", u32FixerIds));
return rc;
}
/**
* Finalize the GCM initialization.
*
* This is called after initializing HM and most other VMM components.
*
* @returns VBox status code.
* @param pVM The cross context VM structure.
* @thread EMT(0)
*/
VMMR3_INT_DECL(int) GCMR3InitCompleted(PVM pVM)
{
RT_NOREF(pVM);
return VINF_SUCCESS;
}
/**
* @callback_method_impl{FNSSMINTSAVEEXEC}
*/
static DECLCALLBACK(int) gcmR3Save(PVM pVM, PSSMHANDLE pSSM)
{
AssertReturn(pVM, VERR_INVALID_PARAMETER);
AssertReturn(pSSM, VERR_SSM_INVALID_STATE);
int rc = VINF_SUCCESS;
/*
* Save per-VM data.
*/
SSMR3PutU32(pSSM, pVM->gcm.s.enmFixerIds);
return rc;
}
/**
* @callback_method_impl{FNSSMINTLOADEXEC}
*/
static DECLCALLBACK(int) gcmR3Load(PVM pVM, PSSMHANDLE pSSM, uint32_t uVersion, uint32_t uPass)
{
if (uPass != SSM_PASS_FINAL)
return VINF_SUCCESS;
if (uVersion != GCM_SAVED_STATE_VERSION)
return VERR_SSM_UNSUPPORTED_DATA_UNIT_VERSION;
int rc;
/*
* Load per-VM data.
*/
uint32_t uFixerIds;
rc = SSMR3GetU32(pSSM, &uFixerIds);
AssertRCReturn(rc, rc);
if ((GCMFIXERID)uFixerIds != pVM->gcm.s.enmFixerIds)
return SSMR3SetCfgError(pSSM, RT_SRC_POS, N_("Saved GCM fixer set %#X differs from the configured one (%#X)."),
uFixerIds, pVM->gcm.s.enmFixerIds);
return VINF_SUCCESS;
}
/**
* Terminates the GCM.
*
* Termination means cleaning up and freeing all resources,
* the VM itself is, at this point, powered off or suspended.
*
* @returns VBox status code.
* @param pVM The cross context VM structure.
*/
VMMR3_INT_DECL(int) GCMR3Term(PVM pVM)
{
RT_NOREF(pVM);
return VINF_SUCCESS;
}
/**
* Applies relocations to data and code managed by this
* component. This function will be called at init and
* whenever the VMM need to relocate itself inside the GC.
*
* @param pVM The cross context VM structure.
* @param offDelta Relocation delta relative to old location.
*/
VMMR3_INT_DECL(void) GCMR3Relocate(PVM pVM, RTGCINTPTR offDelta)
{
RT_NOREF(pVM);
RT_NOREF(offDelta);
}
/**
* The VM is being reset.
*
* Do whatever fixer-specific resetting that needs to be done.
*
* @param pVM The cross context VM structure.
*/
VMMR3_INT_DECL(void) GCMR3Reset(PVM pVM)
{
RT_NOREF(pVM);
}
|
