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1 | /** @file\r | |
2 | \r | |
3 | Secure Encrypted Virtualization (SEV) library helper function\r | |
4 | \r | |
5 | Copyright (c) 2017 - 2020, AMD Incorporated. All rights reserved.<BR>\r | |
6 | \r | |
7 | SPDX-License-Identifier: BSD-2-Clause-Patent\r | |
8 | \r | |
9 | **/\r | |
10 | \r | |
11 | #include <Library/BaseLib.h>\r | |
12 | #include <Library/DebugLib.h>\r | |
13 | #include <Library/MemEncryptSevLib.h>\r | |
14 | #include <Library/PcdLib.h>\r | |
15 | #include <Register/Amd/Cpuid.h>\r | |
16 | #include <Register/Amd/Msr.h>\r | |
17 | #include <Register/Cpuid.h>\r | |
18 | #include <Uefi/UefiBaseType.h>\r | |
19 | \r | |
20 | STATIC BOOLEAN mSevStatus = FALSE;\r | |
21 | STATIC BOOLEAN mSevEsStatus = FALSE;\r | |
22 | STATIC BOOLEAN mSevStatusChecked = FALSE;\r | |
23 | \r | |
24 | STATIC UINT64 mSevEncryptionMask = 0;\r | |
25 | STATIC BOOLEAN mSevEncryptionMaskSaved = FALSE;\r | |
26 | \r | |
27 | /**\r | |
28 | Reads and sets the status of SEV features.\r | |
29 | \r | |
30 | **/\r | |
31 | STATIC\r | |
32 | VOID\r | |
33 | EFIAPI\r | |
34 | InternalMemEncryptSevStatus (\r | |
35 | VOID\r | |
36 | )\r | |
37 | {\r | |
38 | UINT32 RegEax;\r | |
39 | MSR_SEV_STATUS_REGISTER Msr;\r | |
40 | CPUID_MEMORY_ENCRYPTION_INFO_EAX Eax;\r | |
41 | BOOLEAN ReadSevMsr;\r | |
42 | UINT64 EncryptionMask;\r | |
43 | \r | |
44 | ReadSevMsr = FALSE;\r | |
45 | \r | |
46 | EncryptionMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask);\r | |
47 | if (EncryptionMask != 0) {\r | |
48 | //\r | |
49 | // The MSR has been read before, so it is safe to read it again and avoid\r | |
50 | // having to validate the CPUID information.\r | |
51 | //\r | |
52 | ReadSevMsr = TRUE;\r | |
53 | } else {\r | |
54 | //\r | |
55 | // Check if memory encryption leaf exist\r | |
56 | //\r | |
57 | AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL);\r | |
58 | if (RegEax >= CPUID_MEMORY_ENCRYPTION_INFO) {\r | |
59 | //\r | |
60 | // CPUID Fn8000_001F[EAX] Bit 1 (Sev supported)\r | |
61 | //\r | |
62 | AsmCpuid (CPUID_MEMORY_ENCRYPTION_INFO, &Eax.Uint32, NULL, NULL, NULL);\r | |
63 | \r | |
64 | if (Eax.Bits.SevBit) {\r | |
65 | ReadSevMsr = TRUE;\r | |
66 | }\r | |
67 | }\r | |
68 | }\r | |
69 | \r | |
70 | if (ReadSevMsr) {\r | |
71 | //\r | |
72 | // Check MSR_0xC0010131 Bit 0 (Sev Enabled)\r | |
73 | //\r | |
74 | Msr.Uint32 = AsmReadMsr32 (MSR_SEV_STATUS);\r | |
75 | if (Msr.Bits.SevBit) {\r | |
76 | mSevStatus = TRUE;\r | |
77 | }\r | |
78 | \r | |
79 | //\r | |
80 | // Check MSR_0xC0010131 Bit 1 (Sev-Es Enabled)\r | |
81 | //\r | |
82 | if (Msr.Bits.SevEsBit) {\r | |
83 | mSevEsStatus = TRUE;\r | |
84 | }\r | |
85 | }\r | |
86 | \r | |
87 | mSevStatusChecked = TRUE;\r | |
88 | }\r | |
89 | \r | |
90 | /**\r | |
91 | Returns a boolean to indicate whether SEV-ES is enabled.\r | |
92 | \r | |
93 | @retval TRUE SEV-ES is enabled\r | |
94 | @retval FALSE SEV-ES is not enabled\r | |
95 | **/\r | |
96 | BOOLEAN\r | |
97 | EFIAPI\r | |
98 | MemEncryptSevEsIsEnabled (\r | |
99 | VOID\r | |
100 | )\r | |
101 | {\r | |
102 | if (!mSevStatusChecked) {\r | |
103 | InternalMemEncryptSevStatus ();\r | |
104 | }\r | |
105 | \r | |
106 | return mSevEsStatus;\r | |
107 | }\r | |
108 | \r | |
109 | /**\r | |
110 | Returns a boolean to indicate whether SEV is enabled.\r | |
111 | \r | |
112 | @retval TRUE SEV is enabled\r | |
113 | @retval FALSE SEV is not enabled\r | |
114 | **/\r | |
115 | BOOLEAN\r | |
116 | EFIAPI\r | |
117 | MemEncryptSevIsEnabled (\r | |
118 | VOID\r | |
119 | )\r | |
120 | {\r | |
121 | if (!mSevStatusChecked) {\r | |
122 | InternalMemEncryptSevStatus ();\r | |
123 | }\r | |
124 | \r | |
125 | return mSevStatus;\r | |
126 | }\r | |
127 | \r | |
128 | /**\r | |
129 | Returns the SEV encryption mask.\r | |
130 | \r | |
131 | @return The SEV pagtable encryption mask\r | |
132 | **/\r | |
133 | UINT64\r | |
134 | EFIAPI\r | |
135 | MemEncryptSevGetEncryptionMask (\r | |
136 | VOID\r | |
137 | )\r | |
138 | {\r | |
139 | if (!mSevEncryptionMaskSaved) {\r | |
140 | mSevEncryptionMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask);\r | |
141 | mSevEncryptionMaskSaved = TRUE;\r | |
142 | }\r | |
143 | \r | |
144 | return mSevEncryptionMask;\r | |
145 | }\r |