BaseTools/Capsule: Do not support -o with --dump-info
[mirror_edk2.git] / OvmfPkg / AmdSevDxe / AmdSevDxe.c
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1/** @file\r
2\r
3 AMD Sev Dxe driver. This driver is dispatched early in DXE, due to being list\r
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4 in APRIORI. It clears C-bit from MMIO and NonExistent Memory space when SEV\r
5 is enabled.\r
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6\r
7 Copyright (c) 2017, AMD Inc. All rights reserved.<BR>\r
8\r
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9 This program and the accompanying materials are licensed and made available\r
10 under the terms and conditions of the BSD License which accompanies this\r
11 distribution. The full text of the license may be found at\r
12 http://opensource.org/licenses/bsd-license.php\r
24e4ad75 13\r
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14 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT\r
15 WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
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16\r
17**/\r
18\r
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19#include <Library/BaseLib.h>\r
20#include <Library/BaseMemoryLib.h>\r
c6073a0e 21#include <Library/DebugLib.h>\r
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22#include <Library/DxeServicesTableLib.h>\r
23#include <Library/MemEncryptSevLib.h>\r
c6073a0e 24#include <Library/MemoryAllocationLib.h>\r
5e2e5647 25#include <Library/PcdLib.h>\r
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26\r
27EFI_STATUS\r
28EFIAPI\r
29AmdSevDxeEntryPoint (\r
30 IN EFI_HANDLE ImageHandle,\r
31 IN EFI_SYSTEM_TABLE *SystemTable\r
32 )\r
33{\r
34 EFI_STATUS Status;\r
35 EFI_GCD_MEMORY_SPACE_DESCRIPTOR *AllDescMap;\r
36 UINTN NumEntries;\r
37 UINTN Index;\r
38\r
39 //\r
40 // Do nothing when SEV is not enabled\r
41 //\r
42 if (!MemEncryptSevIsEnabled ()) {\r
43 return EFI_UNSUPPORTED;\r
44 }\r
45\r
46 //\r
47 // Iterate through the GCD map and clear the C-bit from MMIO and NonExistent\r
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48 // memory space. The NonExistent memory space will be used for mapping the\r
49 // MMIO space added later (eg PciRootBridge). By clearing both known MMIO and\r
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50 // NonExistent memory space can gurantee that current and furture MMIO adds\r
51 // will have C-bit cleared.\r
52 //\r
53 Status = gDS->GetMemorySpaceMap (&NumEntries, &AllDescMap);\r
54 if (!EFI_ERROR (Status)) {\r
55 for (Index = 0; Index < NumEntries; Index++) {\r
56 CONST EFI_GCD_MEMORY_SPACE_DESCRIPTOR *Desc;\r
57\r
58 Desc = &AllDescMap[Index];\r
59 if (Desc->GcdMemoryType == EfiGcdMemoryTypeMemoryMappedIo ||\r
60 Desc->GcdMemoryType == EfiGcdMemoryTypeNonExistent) {\r
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61 Status = MemEncryptSevClearPageEncMask (\r
62 0,\r
63 Desc->BaseAddress,\r
64 EFI_SIZE_TO_PAGES (Desc->Length),\r
65 FALSE\r
66 );\r
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67 ASSERT_EFI_ERROR (Status);\r
68 }\r
69 }\r
70\r
71 FreePool (AllDescMap);\r
72 }\r
73\r
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74 //\r
75 // When SMM is enabled, clear the C-bit from SMM Saved State Area\r
76 //\r
77 // NOTES: The SavedStateArea address cleared here is before SMBASE\r
78 // relocation. Currently, we do not clear the SavedStateArea address after\r
79 // SMBASE is relocated due to the following reasons:\r
80 //\r
81 // 1) Guest BIOS never access the relocated SavedStateArea.\r
82 //\r
83 // 2) The C-bit works on page-aligned address, but the SavedStateArea\r
84 // address is not a page-aligned. Theoretically, we could roundup the address\r
85 // and clear the C-bit of aligned address but looking carefully we found\r
86 // that some portion of the page contains code -- which will causes a bigger\r
87 // issues for SEV guest. When SEV is enabled, all the code must be encrypted\r
88 // otherwise hardware will cause trap.\r
89 //\r
90 // We restore the C-bit for this SMM Saved State Area after SMBASE relocation\r
91 // is completed (See OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c).\r
92 //\r
93 if (FeaturePcdGet (PcdSmmSmramRequire)) {\r
94 UINTN MapPagesBase;\r
95 UINTN MapPagesCount;\r
96\r
97 Status = MemEncryptSevLocateInitialSmramSaveStateMapPages (\r
98 &MapPagesBase,\r
99 &MapPagesCount\r
100 );\r
101 ASSERT_EFI_ERROR (Status);\r
102\r
103 //\r
104 // Although these pages were set aside (i.e., allocated) by PlatformPei, we\r
105 // could be after a warm reboot from the OS. Don't leak any stale OS data\r
106 // to the hypervisor.\r
107 //\r
108 ZeroMem ((VOID *)MapPagesBase, EFI_PAGES_TO_SIZE (MapPagesCount));\r
109\r
110 Status = MemEncryptSevClearPageEncMask (\r
111 0, // Cr3BaseAddress -- use current CR3\r
112 MapPagesBase, // BaseAddress\r
113 MapPagesCount, // NumPages\r
114 TRUE // Flush\r
115 );\r
116 if (EFI_ERROR (Status)) {\r
117 DEBUG ((DEBUG_ERROR, "%a: MemEncryptSevClearPageEncMask(): %r\n",\r
118 __FUNCTION__, Status));\r
119 ASSERT (FALSE);\r
120 CpuDeadLoop ();\r
121 }\r
122 }\r
123\r
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124 return EFI_SUCCESS;\r
125}\r