1 /** @file
2 
3   Virtual Memory Management Services to set or clear the memory encryption bit
4 
5   Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
6   Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
7 
8   SPDX-License-Identifier: BSD-2-Clause-Patent
9 
10   Code is derived from MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.h
11 
12 **/
13 
14 #ifndef __VIRTUAL_MEMORY__
15 #define __VIRTUAL_MEMORY__
16 
17 #include <Library/BaseLib.h>
18 #include <Library/BaseMemoryLib.h>
19 #include <Library/CacheMaintenanceLib.h>
20 #include <Library/DebugLib.h>
21 #include <Library/MemoryAllocationLib.h>
22 #include <Uefi.h>
23 
24 #define SYS_CODE64_SEL 0x38
25 
26 #pragma pack(1)
27 
28 //
29 // Page-Map Level-4 Offset (PML4) and
30 // Page-Directory-Pointer Offset (PDPE) entries 4K & 2MB
31 //
32 
33 typedef union {
34   struct {
35     UINT64  Present:1;                // 0 = Not present in memory,
36                                       //   1 = Present in memory
37     UINT64  ReadWrite:1;              // 0 = Read-Only, 1= Read/Write
38     UINT64  UserSupervisor:1;         // 0 = Supervisor, 1=User
39     UINT64  WriteThrough:1;           // 0 = Write-Back caching,
40                                       //   1 = Write-Through caching
41     UINT64  CacheDisabled:1;          // 0 = Cached, 1=Non-Cached
42     UINT64  Accessed:1;               // 0 = Not accessed,
43                                       //   1 = Accessed (set by CPU)
44     UINT64  Reserved:1;               // Reserved
45     UINT64  MustBeZero:2;             // Must Be Zero
46     UINT64  Available:3;              // Available for use by system software
47     UINT64  PageTableBaseAddress:40;  // Page Table Base Address
48     UINT64  AvabilableHigh:11;        // Available for use by system software
49     UINT64  Nx:1;                     // No Execute bit
50   } Bits;
51   UINT64    Uint64;
52 } PAGE_MAP_AND_DIRECTORY_POINTER;
53 
54 //
55 // Page Table Entry 4KB
56 //
57 typedef union {
58   struct {
59     UINT64  Present:1;                // 0 = Not present in memory,
60                                       //   1 = Present in memory
61     UINT64  ReadWrite:1;              // 0 = Read-Only, 1= Read/Write
62     UINT64  UserSupervisor:1;         // 0 = Supervisor, 1=User
63     UINT64  WriteThrough:1;           // 0 = Write-Back caching,
64                                       //   1 = Write-Through caching
65     UINT64  CacheDisabled:1;          // 0 = Cached, 1=Non-Cached
66     UINT64  Accessed:1;               // 0 = Not accessed,
67                                       //   1 = Accessed (set by CPU)
68     UINT64  Dirty:1;                  // 0 = Not Dirty, 1 = written by
69                                       //   processor on access to page
70     UINT64  PAT:1;                    //
71     UINT64  Global:1;                 // 0 = Not global page, 1 = global page
72                                       //   TLB not cleared on CR3 write
73     UINT64  Available:3;              // Available for use by system software
74     UINT64  PageTableBaseAddress:40;  // Page Table Base Address
75     UINT64  AvabilableHigh:11;        // Available for use by system software
76     UINT64  Nx:1;                     // 0 = Execute Code,
77                                       //   1 = No Code Execution
78   } Bits;
79   UINT64    Uint64;
80 } PAGE_TABLE_4K_ENTRY;
81 
82 //
83 // Page Table Entry 2MB
84 //
85 typedef union {
86   struct {
87     UINT64  Present:1;                // 0 = Not present in memory,
88                                       //   1 = Present in memory
89     UINT64  ReadWrite:1;              // 0 = Read-Only, 1= Read/Write
90     UINT64  UserSupervisor:1;         // 0 = Supervisor, 1=User
91     UINT64  WriteThrough:1;           // 0 = Write-Back caching,
92                                       //   1=Write-Through caching
93     UINT64  CacheDisabled:1;          // 0 = Cached, 1=Non-Cached
94     UINT64  Accessed:1;               // 0 = Not accessed,
95                                       //   1 = Accessed (set by CPU)
96     UINT64  Dirty:1;                  // 0 = Not Dirty, 1 = written by
97                                       //   processor on access to page
98     UINT64  MustBe1:1;                // Must be 1
99     UINT64  Global:1;                 // 0 = Not global page, 1 = global page
100                                       //   TLB not cleared on CR3 write
101     UINT64  Available:3;              // Available for use by system software
102     UINT64  PAT:1;                    //
103     UINT64  MustBeZero:8;             // Must be zero;
104     UINT64  PageTableBaseAddress:31;  // Page Table Base Address
105     UINT64  AvabilableHigh:11;        // Available for use by system software
106     UINT64  Nx:1;                     // 0 = Execute Code,
107                                       //   1 = No Code Execution
108   } Bits;
109   UINT64    Uint64;
110 } PAGE_TABLE_ENTRY;
111 
112 //
113 // Page Table Entry 1GB
114 //
115 typedef union {
116   struct {
117     UINT64  Present:1;                // 0 = Not present in memory,
118                                       //   1 = Present in memory
119     UINT64  ReadWrite:1;              // 0 = Read-Only, 1= Read/Write
120     UINT64  UserSupervisor:1;         // 0 = Supervisor, 1=User
121     UINT64  WriteThrough:1;           // 0 = Write-Back caching,
122                                       //   1 = Write-Through caching
123     UINT64  CacheDisabled:1;          // 0 = Cached, 1=Non-Cached
124     UINT64  Accessed:1;               // 0 = Not accessed,
125                                       //   1 = Accessed (set by CPU)
126     UINT64  Dirty:1;                  // 0 = Not Dirty, 1 = written by
127                                       //   processor on access to page
128     UINT64  MustBe1:1;                // Must be 1
129     UINT64  Global:1;                 // 0 = Not global page, 1 = global page
130                                       //   TLB not cleared on CR3 write
131     UINT64  Available:3;              // Available for use by system software
132     UINT64  PAT:1;                    //
133     UINT64  MustBeZero:17;            // Must be zero;
134     UINT64  PageTableBaseAddress:22;  // Page Table Base Address
135     UINT64  AvabilableHigh:11;        // Available for use by system software
136     UINT64  Nx:1;                     // 0 = Execute Code,
137                                       //   1 = No Code Execution
138   } Bits;
139   UINT64    Uint64;
140 } PAGE_TABLE_1G_ENTRY;
141 
142 #pragma pack()
143 
144 #define IA32_PG_P                   BIT0
145 #define IA32_PG_RW                  BIT1
146 #define IA32_PG_PS                  BIT7
147 
148 #define PAGING_PAE_INDEX_MASK       0x1FF
149 
150 #define PAGING_4K_ADDRESS_MASK_64   0x000FFFFFFFFFF000ull
151 #define PAGING_2M_ADDRESS_MASK_64   0x000FFFFFFFE00000ull
152 #define PAGING_1G_ADDRESS_MASK_64   0x000FFFFFC0000000ull
153 
154 #define PAGING_L1_ADDRESS_SHIFT     12
155 #define PAGING_L2_ADDRESS_SHIFT     21
156 #define PAGING_L3_ADDRESS_SHIFT     30
157 #define PAGING_L4_ADDRESS_SHIFT     39
158 
159 #define PAGING_PML4E_NUMBER         4
160 
161 #define PAGETABLE_ENTRY_MASK        ((1UL << 9) - 1)
162 #define PML4_OFFSET(x)              ( (x >> 39) & PAGETABLE_ENTRY_MASK)
163 #define PDP_OFFSET(x)               ( (x >> 30) & PAGETABLE_ENTRY_MASK)
164 #define PDE_OFFSET(x)               ( (x >> 21) & PAGETABLE_ENTRY_MASK)
165 #define PTE_OFFSET(x)               ( (x >> 12) & PAGETABLE_ENTRY_MASK)
166 #define PAGING_1G_ADDRESS_MASK_64   0x000FFFFFC0000000ull
167 
168 #define PAGE_TABLE_POOL_ALIGNMENT   BASE_2MB
169 #define PAGE_TABLE_POOL_UNIT_SIZE   SIZE_2MB
170 #define PAGE_TABLE_POOL_UNIT_PAGES  \
171   EFI_SIZE_TO_PAGES (PAGE_TABLE_POOL_UNIT_SIZE)
172 #define PAGE_TABLE_POOL_ALIGN_MASK  \
173   (~(EFI_PHYSICAL_ADDRESS)(PAGE_TABLE_POOL_ALIGNMENT - 1))
174 
175 typedef struct {
176   VOID            *NextPool;
177   UINTN           Offset;
178   UINTN           FreePages;
179 } PAGE_TABLE_POOL;
180 
181 
182 
183 /**
184   This function clears memory encryption bit for the memory region specified by
185   PhysicalAddress and Length from the current page table context.
186 
187   @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
188                                       current CR3)
189   @param[in]  PhysicalAddress         The physical address that is the start
190                                       address of a memory region.
191   @param[in]  Length                  The length of memory region
192   @param[in]  Flush                   Flush the caches before applying the
193                                       encryption mask
194 
195   @retval RETURN_SUCCESS              The attributes were cleared for the
196                                       memory region.
197   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
198   @retval RETURN_UNSUPPORTED          Clearing the memory encyrption attribute
199                                       is not supported
200 **/
201 RETURN_STATUS
202 EFIAPI
203 InternalMemEncryptSevSetMemoryDecrypted (
204   IN  PHYSICAL_ADDRESS        Cr3BaseAddress,
205   IN  PHYSICAL_ADDRESS        PhysicalAddress,
206   IN  UINTN                   Length,
207   IN  BOOLEAN                 Flush
208   );
209 
210 /**
211   This function sets memory encryption bit for the memory region specified by
212   PhysicalAddress and Length from the current page table context.
213 
214   @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
215                                       current CR3)
216   @param[in]  PhysicalAddress         The physical address that is the start
217                                       address of a memory region.
218   @param[in]  Length                  The length of memory region
219   @param[in]  Flush                   Flush the caches before applying the
220                                       encryption mask
221 
222   @retval RETURN_SUCCESS              The attributes were set for the memory
223                                       region.
224   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
225   @retval RETURN_UNSUPPORTED          Setting the memory encyrption attribute
226                                       is not supported
227 **/
228 RETURN_STATUS
229 EFIAPI
230 InternalMemEncryptSevSetMemoryEncrypted (
231   IN  PHYSICAL_ADDRESS        Cr3BaseAddress,
232   IN  PHYSICAL_ADDRESS        PhysicalAddress,
233   IN  UINTN                   Length,
234   IN  BOOLEAN                 Flush
235   );
236 
237 #endif
238