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
|
/** @file
VMGEXIT Support Library.
Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Base.h>
#include <Uefi.h>
#include <Library/BaseMemoryLib.h>
#include <Library/VmgExitLib.h>
#include <Register/Amd/Msr.h>
/**
Check for VMGEXIT error
Check if the hypervisor has returned an error after completion of the VMGEXIT
by examining the SwExitInfo1 field of the GHCB.
@param[in] Ghcb A pointer to the GHCB
@retval 0 VMGEXIT succeeded.
@return Exception number to be propagated, VMGEXIT processing
did not succeed.
**/
STATIC
UINT64
VmgExitErrorCheck (
IN GHCB *Ghcb
)
{
GHCB_EVENT_INJECTION Event;
GHCB_EXIT_INFO ExitInfo;
UINT64 Status;
ExitInfo.Uint64 = Ghcb->SaveArea.SwExitInfo1;
ASSERT ((ExitInfo.Elements.Lower32Bits == 0) ||
(ExitInfo.Elements.Lower32Bits == 1));
Status = 0;
if (ExitInfo.Elements.Lower32Bits == 0) {
return Status;
}
if (ExitInfo.Elements.Lower32Bits == 1) {
ASSERT (Ghcb->SaveArea.SwExitInfo2 != 0);
//
// Check that the return event is valid
//
Event.Uint64 = Ghcb->SaveArea.SwExitInfo2;
if (Event.Elements.Valid &&
Event.Elements.Type == GHCB_EVENT_INJECTION_TYPE_EXCEPTION) {
switch (Event.Elements.Vector) {
case GP_EXCEPTION:
case UD_EXCEPTION:
//
// Use returned event as return code
//
Status = Event.Uint64;
}
}
}
if (Status == 0) {
GHCB_EVENT_INJECTION GpEvent;
GpEvent.Uint64 = 0;
GpEvent.Elements.Vector = GP_EXCEPTION;
GpEvent.Elements.Type = GHCB_EVENT_INJECTION_TYPE_EXCEPTION;
GpEvent.Elements.Valid = 1;
Status = GpEvent.Uint64;
}
return Status;
}
/**
Perform VMGEXIT.
Sets the necessary fields of the GHCB, invokes the VMGEXIT instruction and
then handles the return actions.
@param[in, out] Ghcb A pointer to the GHCB
@param[in] ExitCode VMGEXIT code to be assigned to the SwExitCode
field of the GHCB.
@param[in] ExitInfo1 VMGEXIT information to be assigned to the
SwExitInfo1 field of the GHCB.
@param[in] ExitInfo2 VMGEXIT information to be assigned to the
SwExitInfo2 field of the GHCB.
@retval 0 VMGEXIT succeeded.
@return Exception number to be propagated, VMGEXIT
processing did not succeed.
**/
UINT64
EFIAPI
VmgExit (
IN OUT GHCB *Ghcb,
IN UINT64 ExitCode,
IN UINT64 ExitInfo1,
IN UINT64 ExitInfo2
)
{
Ghcb->SaveArea.SwExitCode = ExitCode;
Ghcb->SaveArea.SwExitInfo1 = ExitInfo1;
Ghcb->SaveArea.SwExitInfo2 = ExitInfo2;
//
// Guest memory is used for the guest-hypervisor communication, so fence
// the invocation of the VMGEXIT instruction to ensure GHCB accesses are
// synchronized properly.
//
MemoryFence ();
AsmVmgExit ();
MemoryFence ();
return VmgExitErrorCheck (Ghcb);
}
/**
Perform pre-VMGEXIT initialization/preparation.
Performs the necessary steps in preparation for invoking VMGEXIT. Must be
called before setting any fields within the GHCB.
@param[in, out] Ghcb A pointer to the GHCB
**/
VOID
EFIAPI
VmgInit (
IN OUT GHCB *Ghcb
)
{
SetMem (&Ghcb->SaveArea, sizeof (Ghcb->SaveArea), 0);
}
/**
Perform post-VMGEXIT cleanup.
Performs the necessary steps to cleanup after invoking VMGEXIT. Must be
called after obtaining needed fields within the GHCB.
@param[in, out] Ghcb A pointer to the GHCB
**/
VOID
EFIAPI
VmgDone (
IN OUT GHCB *Ghcb
)
{
}
|
