From 24e4ad75546b3c1f334aab7057f6c10309807d8d Mon Sep 17 00:00:00 2001 From: Brijesh Singh Date: Thu, 6 Jul 2017 09:26:45 -0400 Subject: [PATCH] OvmfPkg: Add AmdSevDxe driver When SEV is enabled, the MMIO memory range must be mapped as unencrypted (i.e C-bit cleared). We need to clear the C-bit for MMIO GCD entries in order to cover the ranges that were added during the PEI phase (through memory resource descriptor HOBs). Additionally, the NonExistent ranges are processed in order to cover, in advance, MMIO ranges added later in the DXE phase by various device drivers, via the appropriate DXE memory space services. The approach is not transparent for later addition of system memory ranges to the GCD memory space map. (Such ranges should be encrypted.) OVMF does not do such a thing at the moment, so this approach should be OK. The driver is being added to the APRIORI DXE file so that, we clear the C-bit from MMIO regions before any driver accesses it. Cc: Jordan Justen Cc: Laszlo Ersek Cc: Leo Duran Cc: Jiewen Yao Contributed-under: TianoCore Contribution Agreement 1.0 Suggested-by: Jiewen Yao Signed-off-by: Brijesh Singh Reviewed-by: Jiewen Yao Reviewed-by: Laszlo Ersek Acked-by: Jordan Justen --- OvmfPkg/AmdSevDxe/AmdSevDxe.c | 75 +++++++++++++++++++++++++++++++++ OvmfPkg/AmdSevDxe/AmdSevDxe.inf | 43 +++++++++++++++++++ OvmfPkg/OvmfPkgIa32X64.dsc | 1 + OvmfPkg/OvmfPkgIa32X64.fdf | 2 + OvmfPkg/OvmfPkgX64.dsc | 1 + OvmfPkg/OvmfPkgX64.fdf | 2 + 6 files changed, 124 insertions(+) create mode 100644 OvmfPkg/AmdSevDxe/AmdSevDxe.c create mode 100644 OvmfPkg/AmdSevDxe/AmdSevDxe.inf 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.
+ + 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 + +#include +#include +#include +#include +#include +#include +#include + +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.
+# +# 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 diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc index edacd655d1..b3a22c726b 100644 --- a/OvmfPkg/OvmfPkgIa32X64.dsc +++ b/OvmfPkg/OvmfPkgIa32X64.dsc @@ -825,6 +825,7 @@ !endif OvmfPkg/PlatformDxe/Platform.inf + OvmfPkg/AmdSevDxe/AmdSevDxe.inf !if $(SMM_REQUIRE) == TRUE OvmfPkg/SmmAccess/SmmAccess2Dxe.inf diff --git a/OvmfPkg/OvmfPkgIa32X64.fdf b/OvmfPkg/OvmfPkgIa32X64.fdf index fae82709ae..5cec9982db 100644 --- a/OvmfPkg/OvmfPkgIa32X64.fdf +++ b/OvmfPkg/OvmfPkgIa32X64.fdf @@ -191,6 +191,7 @@ READ_LOCK_STATUS = TRUE APRIORI DXE { INF MdeModulePkg/Universal/DevicePathDxe/DevicePathDxe.inf INF MdeModulePkg/Universal/PCD/Dxe/Pcd.inf + INF OvmfPkg/AmdSevDxe/AmdSevDxe.inf !if $(SMM_REQUIRE) == FALSE INF OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FvbServicesRuntimeDxe.inf !endif @@ -352,6 +353,7 @@ INF RuleOverride=CSM OvmfPkg/Csm/Csm16/Csm16.inf INF OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf INF OvmfPkg/VirtioGpuDxe/VirtioGpu.inf INF OvmfPkg/PlatformDxe/Platform.inf +INF OvmfPkg/AmdSevDxe/AmdSevDxe.inf !if $(SMM_REQUIRE) == TRUE INF OvmfPkg/SmmAccess/SmmAccess2Dxe.inf diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc index 93933612a3..aba4d907b5 100644 --- a/OvmfPkg/OvmfPkgX64.dsc +++ b/OvmfPkg/OvmfPkgX64.dsc @@ -823,6 +823,7 @@ !endif OvmfPkg/PlatformDxe/Platform.inf + OvmfPkg/AmdSevDxe/AmdSevDxe.inf !if $(SMM_REQUIRE) == TRUE OvmfPkg/SmmAccess/SmmAccess2Dxe.inf diff --git a/OvmfPkg/OvmfPkgX64.fdf b/OvmfPkg/OvmfPkgX64.fdf index 4da0b19b94..213db6bedb 100644 --- a/OvmfPkg/OvmfPkgX64.fdf +++ b/OvmfPkg/OvmfPkgX64.fdf @@ -191,6 +191,7 @@ READ_LOCK_STATUS = TRUE APRIORI DXE { INF MdeModulePkg/Universal/DevicePathDxe/DevicePathDxe.inf INF MdeModulePkg/Universal/PCD/Dxe/Pcd.inf + INF OvmfPkg/AmdSevDxe/AmdSevDxe.inf !if $(SMM_REQUIRE) == FALSE INF OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FvbServicesRuntimeDxe.inf !endif @@ -352,6 +353,7 @@ INF RuleOverride=CSM OvmfPkg/Csm/Csm16/Csm16.inf INF OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf INF OvmfPkg/VirtioGpuDxe/VirtioGpu.inf INF OvmfPkg/PlatformDxe/Platform.inf +INF OvmfPkg/AmdSevDxe/AmdSevDxe.inf !if $(SMM_REQUIRE) == TRUE INF OvmfPkg/SmmAccess/SmmAccess2Dxe.inf -- 2.39.2