diff options
Diffstat (limited to 'OvmfPkg/AmdSevDxe')
| -rw-r--r-- | OvmfPkg/AmdSevDxe/AmdSevDxe.c | 75 | ||||
| -rw-r--r-- | OvmfPkg/AmdSevDxe/AmdSevDxe.inf | 43 |
2 files changed, 118 insertions, 0 deletions
diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.c b/OvmfPkg/AmdSevDxe/AmdSevDxe.c new file mode 100644 index 0000000000..e472096320 --- /dev/null +++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.c @@ -0,0 +1,75 @@ +/** @file
+
+ AMD Sev Dxe driver. This driver is dispatched early in DXE, due to being list
+ in APRIORI. It clears C-bit from MMIO and NonExistent Memory space when SEV is
+ enabled.
+
+ Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
+
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD
+ License which accompanies this distribution. The full text of the license may
+ be found at http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include <PiDxe.h>
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/DxeServicesTableLib.h>
+#include <Library/MemEncryptSevLib.h>
+
+EFI_STATUS
+EFIAPI
+AmdSevDxeEntryPoint (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+ EFI_GCD_MEMORY_SPACE_DESCRIPTOR *AllDescMap;
+ UINTN NumEntries;
+ UINTN Index;
+
+ //
+ // Do nothing when SEV is not enabled
+ //
+ if (!MemEncryptSevIsEnabled ()) {
+ return EFI_UNSUPPORTED;
+ }
+
+ //
+ // Iterate through the GCD map and clear the C-bit from MMIO and NonExistent
+ // memory space. The NonExistent memory space will be used for mapping the MMIO
+ // space added later (eg PciRootBridge). By clearing both known MMIO and
+ // NonExistent memory space can gurantee that current and furture MMIO adds
+ // will have C-bit cleared.
+ //
+ Status = gDS->GetMemorySpaceMap (&NumEntries, &AllDescMap);
+ if (!EFI_ERROR (Status)) {
+ for (Index = 0; Index < NumEntries; Index++) {
+ CONST EFI_GCD_MEMORY_SPACE_DESCRIPTOR *Desc;
+
+ Desc = &AllDescMap[Index];
+ if (Desc->GcdMemoryType == EfiGcdMemoryTypeMemoryMappedIo ||
+ Desc->GcdMemoryType == EfiGcdMemoryTypeNonExistent) {
+ Status = MemEncryptSevClearPageEncMask (0,
+ Desc->BaseAddress,
+ EFI_SIZE_TO_PAGES(Desc->Length),
+ FALSE);
+ ASSERT_EFI_ERROR (Status);
+ }
+ }
+
+ FreePool (AllDescMap);
+ }
+
+ return EFI_SUCCESS;
+}
diff --git a/OvmfPkg/AmdSevDxe/AmdSevDxe.inf b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf new file mode 100644 index 0000000000..41635a57a4 --- /dev/null +++ b/OvmfPkg/AmdSevDxe/AmdSevDxe.inf @@ -0,0 +1,43 @@ +#/** @file
+#
+# Driver clears the encryption attribute from MMIO regions when SEV is enabled
+#
+# Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
+#
+# This program and the accompanying materials
+# are licensed and made available under the terms and conditions of the BSD
+# License which accompanies this distribution. The full text of the license may
+# be found at http://opensource.org/licenses/bsd-license.php
+#
+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+#**/
+
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = AmdSevDxe
+ FILE_GUID = 2ec9da37-ee35-4de9-86c5-6d9a81dc38a7
+ MODULE_TYPE = DXE_DRIVER
+ VERSION_STRING = 1.0
+ ENTRY_POINT = AmdSevDxeEntryPoint
+
+[Sources]
+ AmdSevDxe.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+ MdeModulePkg/MdeModulePkg.dec
+ OvmfPkg/OvmfPkg.dec
+
+[LibraryClasses]
+ BaseLib
+ UefiLib
+ UefiDriverEntryPoint
+ UefiBootServicesTableLib
+ DxeServicesTableLib
+ DebugLib
+ MemEncryptSevLib
+
+[Depex]
+ TRUE
|