summaryrefslogtreecommitdiffstats
path: root/src/VBox/VMM/VMMRZ/VMMRZ.cpp
blob: b0a7dd37fcd87142d036f6f5ef069662cedfbadc (plain)
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
/* $Id: VMMRZ.cpp $ */
/** @file
 * VMM - Virtual Machine Monitor, Raw-mode and ring-0 context code.
 */

/*
 * Copyright (C) 2009-2019 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 */


/*********************************************************************************************************************************
*   Header Files                                                                                                                 *
*********************************************************************************************************************************/
#include <VBox/vmm/vmm.h>
#include "VMMInternal.h"
#include <VBox/vmm/vm.h>
#include <VBox/err.h>

#include <iprt/assert.h>
#include <iprt/asm-amd64-x86.h>
#include <iprt/string.h>


/**
 * Calls the ring-3 host code.
 *
 * @returns VBox status code of the ring-3 call.
 * @retval  VERR_VMM_RING3_CALL_DISABLED if called at the wrong time. This must
 *          be passed up the stack, or if that isn't possible then VMMRZCallRing3
 *          needs to change it into an assertion.
 *
 *
 * @param   pVM             The cross context VM structure.
 * @param   pVCpu           The cross context virtual CPU structure of the calling EMT.
 * @param   enmOperation    The operation.
 * @param   uArg            The argument to the operation.
 */
VMMRZDECL(int) VMMRZCallRing3(PVM pVM, PVMCPU pVCpu, VMMCALLRING3 enmOperation, uint64_t uArg)
{
    VMCPU_ASSERT_EMT(pVCpu);

    /*
     * Check if calling ring-3 has been disabled and only let let fatal calls thru.
     */
    if (RT_UNLIKELY(    pVCpu->vmm.s.cCallRing3Disabled != 0
                    &&  enmOperation != VMMCALLRING3_VM_R0_ASSERTION))
    {
#ifndef IN_RING0
        /*
         * In most cases, it's sufficient to return a status code which
         * will then be propagated up the code usually encountering several
         * AssertRC invocations along the way. Hitting one of those is more
         * helpful than stopping here.
         *
         * However, some doesn't check the status code because they are called
         * from void functions, and for these we'll turn this into a ring-0
         * assertion host call.
         */
        if (enmOperation != VMMCALLRING3_REM_REPLAY_HANDLER_NOTIFICATIONS)
            return VERR_VMM_RING3_CALL_DISABLED;
#endif
#ifdef IN_RC
        RTStrPrintf(g_szRTAssertMsg1, sizeof(pVM->vmm.s.szRing0AssertMsg1),
                    "VMMRZCallRing3: enmOperation=%d uArg=%#llx idCpu=%#x cCallRing3Disabled=%#x\n",
                    enmOperation, uArg, pVCpu->idCpu, pVCpu->vmm.s.cCallRing3Disabled);
#endif
        RTStrPrintf(pVM->vmm.s.szRing0AssertMsg1, sizeof(pVM->vmm.s.szRing0AssertMsg1),
                    "VMMRZCallRing3: enmOperation=%d uArg=%#llx idCpu=%#x cCallRing3Disabled=%#x\n",
                    enmOperation, uArg, pVCpu->idCpu, pVCpu->vmm.s.cCallRing3Disabled);
        enmOperation = VMMCALLRING3_VM_R0_ASSERTION;
    }

    /*
     * The normal path.
     */
/** @todo profile this! */
    pVCpu->vmm.s.enmCallRing3Operation = enmOperation;
    pVCpu->vmm.s.u64CallRing3Arg = uArg;
    pVCpu->vmm.s.rcCallRing3 = VERR_VMM_RING3_CALL_NO_RC;
#ifdef IN_RC
    pVM->vmm.s.pfnRCToHost(VINF_VMM_CALL_HOST);
#else
    int rc;
    if (pVCpu->vmm.s.pfnCallRing3CallbackR0)
    {
        rc = pVCpu->vmm.s.pfnCallRing3CallbackR0(pVCpu, enmOperation, pVCpu->vmm.s.pvCallRing3CallbackUserR0);
        if (RT_FAILURE(rc))
            return rc;
    }
    rc = vmmR0CallRing3LongJmp(&pVCpu->vmm.s.CallRing3JmpBufR0, VINF_VMM_CALL_HOST);
    if (RT_FAILURE(rc))
        return rc;
#endif
    return pVCpu->vmm.s.rcCallRing3;
}


/**
 * Simple wrapper that adds the pVCpu argument.
 *
 * @returns VBox status code of the ring-3 call.
 * @retval  VERR_VMM_RING3_CALL_DISABLED if called at the wrong time. This must
 *          be passed up the stack, or if that isn't possible then VMMRZCallRing3
 *          needs to change it into an assertion.
 *
 * @param   pVM             The cross context VM structure.
 * @param   enmOperation    The operation.
 * @param   uArg            The argument to the operation.
 */
VMMRZDECL(int) VMMRZCallRing3NoCpu(PVM pVM, VMMCALLRING3 enmOperation, uint64_t uArg)
{
    return VMMRZCallRing3(pVM, VMMGetCpu(pVM), enmOperation, uArg);
}


/**
 * Disables all host calls, except certain fatal ones.
 *
 * @param   pVCpu               The cross context virtual CPU structure of the calling EMT.
 * @thread  EMT.
 */
VMMRZDECL(void) VMMRZCallRing3Disable(PVMCPU pVCpu)
{
    VMCPU_ASSERT_EMT(pVCpu);
#if defined(LOG_ENABLED) && defined(IN_RING0)
    RTCCUINTREG fFlags = ASMIntDisableFlags(); /* preemption consistency. */
#endif

    Assert(pVCpu->vmm.s.cCallRing3Disabled < 16);
    if (ASMAtomicUoIncU32(&pVCpu->vmm.s.cCallRing3Disabled) == 1)
    {
        /** @todo it might make more sense to just disable logging here, then we
         * won't flush away important bits... but that goes both ways really. */
#ifdef IN_RC
        pVCpu->pVMRC->vmm.s.fRCLoggerFlushingDisabled = true;
#else
# ifdef LOG_ENABLED
        if (pVCpu->vmm.s.pR0LoggerR0)
            pVCpu->vmm.s.pR0LoggerR0->fFlushingDisabled = true;
# endif
        if (pVCpu->vmm.s.pR0RelLoggerR0)
            pVCpu->vmm.s.pR0RelLoggerR0->fFlushingDisabled = true;
#endif
    }

#if defined(LOG_ENABLED) && defined(IN_RING0)
    ASMSetFlags(fFlags);
#endif
}


/**
 * Counters VMMRZCallRing3Disable() and re-enables host calls.
 *
 * @param   pVCpu               The cross context virtual CPU structure of the calling EMT.
 * @thread  EMT.
 */
VMMRZDECL(void) VMMRZCallRing3Enable(PVMCPU pVCpu)
{
    VMCPU_ASSERT_EMT(pVCpu);
#if defined(LOG_ENABLED) && defined(IN_RING0)
    RTCCUINTREG fFlags = ASMIntDisableFlags(); /* preemption consistency. */
#endif

    Assert(pVCpu->vmm.s.cCallRing3Disabled > 0);
    if (ASMAtomicUoDecU32(&pVCpu->vmm.s.cCallRing3Disabled) == 0)
    {
#ifdef IN_RC
        pVCpu->pVMRC->vmm.s.fRCLoggerFlushingDisabled = false;
#else
# ifdef LOG_ENABLED
        if (pVCpu->vmm.s.pR0LoggerR0)
            pVCpu->vmm.s.pR0LoggerR0->fFlushingDisabled = false;
# endif
        if (pVCpu->vmm.s.pR0RelLoggerR0)
            pVCpu->vmm.s.pR0RelLoggerR0->fFlushingDisabled = false;
#endif
    }

#if defined(LOG_ENABLED) && defined(IN_RING0)
    ASMSetFlags(fFlags);
#endif
}


/**
 * Checks whether its possible to call host context or not.
 *
 * @returns true if it's safe, false if it isn't.
 * @param   pVCpu               The cross context virtual CPU structure of the calling EMT.
 */
VMMRZDECL(bool) VMMRZCallRing3IsEnabled(PVMCPU pVCpu)
{
    VMCPU_ASSERT_EMT(pVCpu);
    Assert(pVCpu->vmm.s.cCallRing3Disabled <= 16);
    return pVCpu->vmm.s.cCallRing3Disabled == 0;
}


/**
 * Sets the ring-0 callback before doing the ring-3 call.
 *
 * @param   pVCpu         The cross context virtual CPU structure.
 * @param   pfnCallback   Pointer to the callback.
 * @param   pvUser        The user argument.
 *
 * @return VBox status code.
 */
VMMRZDECL(int) VMMRZCallRing3SetNotification(PVMCPU pVCpu, R0PTRTYPE(PFNVMMR0CALLRING3NOTIFICATION) pfnCallback, RTR0PTR pvUser)
{
    AssertPtrReturn(pVCpu, VERR_INVALID_POINTER);
    AssertPtrReturn(pfnCallback, VERR_INVALID_POINTER);

    if (pVCpu->vmm.s.pfnCallRing3CallbackR0)
        return VERR_ALREADY_EXISTS;

    pVCpu->vmm.s.pfnCallRing3CallbackR0    = pfnCallback;
    pVCpu->vmm.s.pvCallRing3CallbackUserR0 = pvUser;
    return VINF_SUCCESS;
}


/**
 * Removes the ring-0 callback.
 *
 * @param   pVCpu   The cross context virtual CPU structure.
 */
VMMRZDECL(void) VMMRZCallRing3RemoveNotification(PVMCPU pVCpu)
{
    pVCpu->vmm.s.pfnCallRing3CallbackR0 = NULL;
}


/**
 * Checks whether there is a ring-0 callback notification active.
 *
 * @param   pVCpu   The cross context virtual CPU structure.
 * @returns true if there the notification is active, false otherwise.
 */
VMMRZDECL(bool) VMMRZCallRing3IsNotificationSet(PVMCPU pVCpu)
{
    return pVCpu->vmm.s.pfnCallRing3CallbackR0 != NULL;
}