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1 | /** @file\r | |
2 | \r | |
3 | Virtual Memory Management Services to test an address range encryption state\r | |
4 | \r | |
5 | Copyright (c) 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/CpuLib.h>\r | |
12 | #include <Library/MemEncryptSevLib.h>\r | |
13 | \r | |
14 | #include "VirtualMemory.h"\r | |
15 | \r | |
16 | /**\r | |
17 | Returns the (updated) address range state based upon the page table\r | |
18 | entry.\r | |
19 | \r | |
20 | @param[in] CurrentState The current address range state\r | |
21 | @param[in] PageDirectoryEntry The page table entry to check\r | |
22 | @param[in] AddressEncMask The encryption mask\r | |
23 | \r | |
24 | @retval MemEncryptSevAddressRangeUnencrypted Address range is mapped\r | |
25 | unencrypted\r | |
26 | @retval MemEncryptSevAddressRangeEncrypted Address range is mapped\r | |
27 | encrypted\r | |
28 | @retval MemEncryptSevAddressRangeMixed Address range is mapped mixed\r | |
29 | **/\r | |
30 | STATIC\r | |
31 | MEM_ENCRYPT_SEV_ADDRESS_RANGE_STATE\r | |
32 | UpdateAddressState (\r | |
33 | IN MEM_ENCRYPT_SEV_ADDRESS_RANGE_STATE CurrentState,\r | |
34 | IN UINT64 PageDirectoryEntry,\r | |
35 | IN UINT64 AddressEncMask\r | |
36 | )\r | |
37 | {\r | |
38 | if (CurrentState == MemEncryptSevAddressRangeEncrypted) {\r | |
39 | if ((PageDirectoryEntry & AddressEncMask) == 0) {\r | |
40 | CurrentState = MemEncryptSevAddressRangeMixed;\r | |
41 | }\r | |
42 | } else if (CurrentState == MemEncryptSevAddressRangeUnencrypted) {\r | |
43 | if ((PageDirectoryEntry & AddressEncMask) != 0) {\r | |
44 | CurrentState = MemEncryptSevAddressRangeMixed;\r | |
45 | }\r | |
46 | } else if (CurrentState == MemEncryptSevAddressRangeError) {\r | |
47 | //\r | |
48 | // First address check, set initial state\r | |
49 | //\r | |
50 | if ((PageDirectoryEntry & AddressEncMask) == 0) {\r | |
51 | CurrentState = MemEncryptSevAddressRangeUnencrypted;\r | |
52 | } else {\r | |
53 | CurrentState = MemEncryptSevAddressRangeEncrypted;\r | |
54 | }\r | |
55 | }\r | |
56 | \r | |
57 | return CurrentState;\r | |
58 | }\r | |
59 | \r | |
60 | /**\r | |
61 | Returns the encryption state of the specified virtual address range.\r | |
62 | \r | |
63 | @param[in] Cr3BaseAddress Cr3 Base Address (if zero then use\r | |
64 | current CR3)\r | |
65 | @param[in] BaseAddress Base address to check\r | |
66 | @param[in] Length Length of virtual address range\r | |
67 | \r | |
68 | @retval MemEncryptSevAddressRangeUnencrypted Address range is mapped\r | |
69 | unencrypted\r | |
70 | @retval MemEncryptSevAddressRangeEncrypted Address range is mapped\r | |
71 | encrypted\r | |
72 | @retval MemEncryptSevAddressRangeMixed Address range is mapped mixed\r | |
73 | @retval MemEncryptSevAddressRangeError Address range is not mapped\r | |
74 | **/\r | |
75 | MEM_ENCRYPT_SEV_ADDRESS_RANGE_STATE\r | |
76 | EFIAPI\r | |
77 | InternalMemEncryptSevGetAddressRangeState (\r | |
78 | IN PHYSICAL_ADDRESS Cr3BaseAddress,\r | |
79 | IN PHYSICAL_ADDRESS BaseAddress,\r | |
80 | IN UINTN Length\r | |
81 | )\r | |
82 | {\r | |
83 | PAGE_MAP_AND_DIRECTORY_POINTER *PageMapLevel4Entry;\r | |
84 | PAGE_MAP_AND_DIRECTORY_POINTER *PageUpperDirectoryPointerEntry;\r | |
85 | PAGE_MAP_AND_DIRECTORY_POINTER *PageDirectoryPointerEntry;\r | |
86 | PAGE_TABLE_1G_ENTRY *PageDirectory1GEntry;\r | |
87 | PAGE_TABLE_ENTRY *PageDirectory2MEntry;\r | |
88 | PAGE_TABLE_4K_ENTRY *PageTableEntry;\r | |
89 | UINT64 AddressEncMask;\r | |
90 | UINT64 PgTableMask;\r | |
91 | PHYSICAL_ADDRESS Address;\r | |
92 | PHYSICAL_ADDRESS AddressEnd;\r | |
93 | MEM_ENCRYPT_SEV_ADDRESS_RANGE_STATE State;\r | |
94 | \r | |
95 | //\r | |
96 | // If Cr3BaseAddress is not specified then read the current CR3\r | |
97 | //\r | |
98 | if (Cr3BaseAddress == 0) {\r | |
99 | Cr3BaseAddress = AsmReadCr3 ();\r | |
100 | }\r | |
101 | \r | |
102 | AddressEncMask = MemEncryptSevGetEncryptionMask ();\r | |
103 | AddressEncMask &= PAGING_1G_ADDRESS_MASK_64;\r | |
104 | \r | |
105 | PgTableMask = AddressEncMask | EFI_PAGE_MASK;\r | |
106 | \r | |
107 | State = MemEncryptSevAddressRangeError;\r | |
108 | \r | |
109 | //\r | |
110 | // Encryption is on a page basis, so start at the beginning of the\r | |
111 | // virtual address page boundary and walk page-by-page.\r | |
112 | //\r | |
113 | Address = (PHYSICAL_ADDRESS)(UINTN)BaseAddress & ~EFI_PAGE_MASK;\r | |
114 | AddressEnd = (PHYSICAL_ADDRESS)\r | |
115 | (UINTN)(BaseAddress + Length);\r | |
116 | \r | |
117 | while (Address < AddressEnd) {\r | |
118 | PageMapLevel4Entry = (VOID *)(Cr3BaseAddress & ~PgTableMask);\r | |
119 | PageMapLevel4Entry += PML4_OFFSET (Address);\r | |
120 | if (!PageMapLevel4Entry->Bits.Present) {\r | |
121 | return MemEncryptSevAddressRangeError;\r | |
122 | }\r | |
123 | \r | |
124 | PageDirectory1GEntry = (VOID *)(\r | |
125 | (PageMapLevel4Entry->Bits.PageTableBaseAddress <<\r | |
126 | 12) & ~PgTableMask\r | |
127 | );\r | |
128 | PageDirectory1GEntry += PDP_OFFSET (Address);\r | |
129 | if (!PageDirectory1GEntry->Bits.Present) {\r | |
130 | return MemEncryptSevAddressRangeError;\r | |
131 | }\r | |
132 | \r | |
133 | //\r | |
134 | // If the MustBe1 bit is not 1, it's not actually a 1GB entry\r | |
135 | //\r | |
136 | if (PageDirectory1GEntry->Bits.MustBe1) {\r | |
137 | //\r | |
138 | // Valid 1GB page\r | |
139 | //\r | |
140 | State = UpdateAddressState (\r | |
141 | State,\r | |
142 | PageDirectory1GEntry->Uint64,\r | |
143 | AddressEncMask\r | |
144 | );\r | |
145 | \r | |
146 | Address += BIT30;\r | |
147 | continue;\r | |
148 | }\r | |
149 | \r | |
150 | //\r | |
151 | // Actually a PDP\r | |
152 | //\r | |
153 | PageUpperDirectoryPointerEntry =\r | |
154 | (PAGE_MAP_AND_DIRECTORY_POINTER *)PageDirectory1GEntry;\r | |
155 | PageDirectory2MEntry =\r | |
156 | (VOID *)(\r | |
157 | (PageUpperDirectoryPointerEntry->Bits.PageTableBaseAddress <<\r | |
158 | 12) & ~PgTableMask\r | |
159 | );\r | |
160 | PageDirectory2MEntry += PDE_OFFSET (Address);\r | |
161 | if (!PageDirectory2MEntry->Bits.Present) {\r | |
162 | return MemEncryptSevAddressRangeError;\r | |
163 | }\r | |
164 | \r | |
165 | //\r | |
166 | // If the MustBe1 bit is not a 1, it's not a 2MB entry\r | |
167 | //\r | |
168 | if (PageDirectory2MEntry->Bits.MustBe1) {\r | |
169 | //\r | |
170 | // Valid 2MB page\r | |
171 | //\r | |
172 | State = UpdateAddressState (\r | |
173 | State,\r | |
174 | PageDirectory2MEntry->Uint64,\r | |
175 | AddressEncMask\r | |
176 | );\r | |
177 | \r | |
178 | Address += BIT21;\r | |
179 | continue;\r | |
180 | }\r | |
181 | \r | |
182 | //\r | |
183 | // Actually a PMD\r | |
184 | //\r | |
185 | PageDirectoryPointerEntry =\r | |
186 | (PAGE_MAP_AND_DIRECTORY_POINTER *)PageDirectory2MEntry;\r | |
187 | PageTableEntry =\r | |
188 | (VOID *)(\r | |
189 | (PageDirectoryPointerEntry->Bits.PageTableBaseAddress <<\r | |
190 | 12) & ~PgTableMask\r | |
191 | );\r | |
192 | PageTableEntry += PTE_OFFSET (Address);\r | |
193 | if (!PageTableEntry->Bits.Present) {\r | |
194 | return MemEncryptSevAddressRangeError;\r | |
195 | }\r | |
196 | \r | |
197 | State = UpdateAddressState (\r | |
198 | State,\r | |
199 | PageTableEntry->Uint64,\r | |
200 | AddressEncMask\r | |
201 | );\r | |
202 | \r | |
203 | Address += EFI_PAGE_SIZE;\r | |
204 | }\r | |
205 | \r | |
206 | return State;\r | |
207 | }\r |