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c05de360 AP |
1 | ;------------------------------------------------------------------------------\r |
2 | ; @file\r | |
3 | ; Sets the CR3 register for 64-bit paging\r | |
4 | ;\r | |
5 | ; Copyright (c) 2008 - 2013, Intel Corporation. All rights reserved.<BR>\r | |
6 | ; Copyright (c) 2019, Citrix Systems, Inc.\r | |
7 | ; SPDX-License-Identifier: BSD-2-Clause-Patent\r | |
8 | ;\r | |
9 | ;------------------------------------------------------------------------------\r | |
10 | \r | |
11 | BITS 32\r | |
12 | \r | |
13 | %define PAGE_PRESENT 0x01\r | |
14 | %define PAGE_READ_WRITE 0x02\r | |
15 | %define PAGE_USER_SUPERVISOR 0x04\r | |
16 | %define PAGE_WRITE_THROUGH 0x08\r | |
17 | %define PAGE_CACHE_DISABLE 0x010\r | |
18 | %define PAGE_ACCESSED 0x020\r | |
19 | %define PAGE_DIRTY 0x040\r | |
20 | %define PAGE_PAT 0x080\r | |
21 | %define PAGE_GLOBAL 0x0100\r | |
22 | %define PAGE_2M_MBO 0x080\r | |
23 | %define PAGE_2M_PAT 0x01000\r | |
24 | \r | |
25 | %define PAGE_2M_PDE_ATTR (PAGE_2M_MBO + \\r | |
26 | PAGE_ACCESSED + \\r | |
27 | PAGE_DIRTY + \\r | |
28 | PAGE_READ_WRITE + \\r | |
29 | PAGE_PRESENT)\r | |
30 | \r | |
31 | %define PAGE_PDP_ATTR (PAGE_ACCESSED + \\r | |
32 | PAGE_READ_WRITE + \\r | |
33 | PAGE_PRESENT)\r | |
34 | \r | |
35 | ; Check if Secure Encrypted Virtualization (SEV) feature is enabled\r | |
36 | ;\r | |
37 | ; If SEV is enabled then EAX will be at least 32\r | |
38 | ; If SEV is disabled then EAX will be zero.\r | |
39 | ;\r | |
40 | CheckSevFeature:\r | |
41 | ; Check if we have a valid (0x8000_001F) CPUID leaf\r | |
42 | mov eax, 0x80000000\r | |
43 | cpuid\r | |
44 | \r | |
45 | ; This check should fail on Intel or Non SEV AMD CPUs. In future if\r | |
46 | ; Intel CPUs supports this CPUID leaf then we are guranteed to have exact\r | |
47 | ; same bit definition.\r | |
48 | cmp eax, 0x8000001f\r | |
49 | jl NoSev\r | |
50 | \r | |
51 | ; Check for memory encryption feature:\r | |
52 | ; CPUID Fn8000_001F[EAX] - Bit 1\r | |
53 | ;\r | |
54 | mov eax, 0x8000001f\r | |
55 | cpuid\r | |
56 | bt eax, 1\r | |
57 | jnc NoSev\r | |
58 | \r | |
59 | ; Check if memory encryption is enabled\r | |
60 | ; MSR_0xC0010131 - Bit 0 (SEV enabled)\r | |
61 | mov ecx, 0xc0010131\r | |
62 | rdmsr\r | |
63 | bt eax, 0\r | |
64 | jnc NoSev\r | |
65 | \r | |
66 | ; Get pte bit position to enable memory encryption\r | |
67 | ; CPUID Fn8000_001F[EBX] - Bits 5:0\r | |
68 | ;\r | |
69 | mov eax, ebx\r | |
70 | and eax, 0x3f\r | |
71 | jmp SevExit\r | |
72 | \r | |
73 | NoSev:\r | |
74 | xor eax, eax\r | |
75 | \r | |
76 | SevExit:\r | |
77 | OneTimeCallRet CheckSevFeature\r | |
78 | \r | |
79 | ;\r | |
80 | ; Modified: EAX, EBX, ECX, EDX\r | |
81 | ;\r | |
82 | SetCr3ForPageTables64:\r | |
83 | \r | |
84 | OneTimeCall CheckSevFeature\r | |
85 | xor edx, edx\r | |
86 | test eax, eax\r | |
87 | jz SevNotActive\r | |
88 | \r | |
89 | ; If SEV is enabled, C-bit is always above 31\r | |
90 | sub eax, 32\r | |
91 | bts edx, eax\r | |
92 | \r | |
93 | SevNotActive:\r | |
94 | \r | |
95 | ;\r | |
96 | ; For OVMF, build some initial page tables at\r | |
97 | ; PcdOvmfSecPageTablesBase - (PcdOvmfSecPageTablesBase + 0x6000).\r | |
98 | ;\r | |
99 | ; This range should match with PcdOvmfSecPageTablesSize which is\r | |
100 | ; declared in the FDF files.\r | |
101 | ;\r | |
102 | ; At the end of PEI, the pages tables will be rebuilt into a\r | |
103 | ; more permanent location by DxeIpl.\r | |
104 | ;\r | |
105 | \r | |
106 | mov ecx, 6 * 0x1000 / 4\r | |
107 | xor eax, eax\r | |
108 | clearPageTablesMemoryLoop:\r | |
109 | mov dword[ecx * 4 + PT_ADDR (0) - 4], eax\r | |
110 | loop clearPageTablesMemoryLoop\r | |
111 | \r | |
112 | ;\r | |
113 | ; Top level Page Directory Pointers (1 * 512GB entry)\r | |
114 | ;\r | |
115 | mov dword[PT_ADDR (0)], PT_ADDR (0x1000) + PAGE_PDP_ATTR\r | |
116 | mov dword[PT_ADDR (4)], edx\r | |
117 | \r | |
118 | ;\r | |
119 | ; Next level Page Directory Pointers (4 * 1GB entries => 4GB)\r | |
120 | ;\r | |
121 | mov dword[PT_ADDR (0x1000)], PT_ADDR (0x2000) + PAGE_PDP_ATTR\r | |
122 | mov dword[PT_ADDR (0x1004)], edx\r | |
123 | mov dword[PT_ADDR (0x1008)], PT_ADDR (0x3000) + PAGE_PDP_ATTR\r | |
124 | mov dword[PT_ADDR (0x100C)], edx\r | |
125 | mov dword[PT_ADDR (0x1010)], PT_ADDR (0x4000) + PAGE_PDP_ATTR\r | |
126 | mov dword[PT_ADDR (0x1014)], edx\r | |
127 | mov dword[PT_ADDR (0x1018)], PT_ADDR (0x5000) + PAGE_PDP_ATTR\r | |
128 | mov dword[PT_ADDR (0x101C)], edx\r | |
129 | \r | |
130 | ;\r | |
131 | ; Page Table Entries (2048 * 2MB entries => 4GB)\r | |
132 | ;\r | |
133 | mov ecx, 0x800\r | |
134 | pageTableEntriesLoop:\r | |
135 | mov eax, ecx\r | |
136 | dec eax\r | |
137 | shl eax, 21\r | |
138 | add eax, PAGE_2M_PDE_ATTR\r | |
139 | mov [ecx * 8 + PT_ADDR (0x2000 - 8)], eax\r | |
140 | mov [(ecx * 8 + PT_ADDR (0x2000 - 8)) + 4], edx\r | |
141 | loop pageTableEntriesLoop\r | |
142 | \r | |
143 | ;\r | |
144 | ; Set CR3 now that the paging structures are available\r | |
145 | ;\r | |
146 | mov eax, PT_ADDR (0)\r | |
147 | mov cr3, eax\r | |
148 | \r | |
149 | OneTimeCallRet SetCr3ForPageTables64\r |