[edk2-devel] [PATCH v2 11/15] OvmfPkg/MemEncryptSevLib: Make the MemEncryptSevLib available for SEC
Lendacky, Thomas
thomas.lendacky at amd.com
Wed Jan 6 21:21:37 UTC 2021
From: Tom Lendacky <thomas.lendacky at amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108
In preparation for a new interface to be added to the MemEncryptSevLib
library that will be used in SEC, create an SEC version of the library.
This requires the creation of SEC specific files.
Some of the current MemEncryptSevLib functions perform memory allocations
which cannot be performed in SEC, so these interfaces will return an error
during SEC. Also, the current MemEncryptSevLib library uses some static
variables to optimize access to variables, which cannot be used in SEC.
Cc: Jordan Justen <jordan.l.justen at intel.com>
Cc: Laszlo Ersek <lersek at redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel at arm.com>
Cc: Brijesh Singh <brijesh.singh at amd.com>
Signed-off-by: Tom Lendacky <thomas.lendacky at amd.com>
---
OvmfPkg/Library/BaseMemEncryptSevLib/DxeMemEncryptSevLib.inf | 4 +-
OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLib.inf | 4 +-
OvmfPkg/Library/BaseMemEncryptSevLib/SecMemEncryptSevLib.inf | 50 +++++++
OvmfPkg/Library/BaseMemEncryptSevLib/{MemEncryptSevLibInternal.c => PeiDxeMemEncryptSevLibInternal.c} | 0
OvmfPkg/Library/BaseMemEncryptSevLib/SecMemEncryptSevLibInternal.c | 155 ++++++++++++++++++++
OvmfPkg/Library/BaseMemEncryptSevLib/X64/{VirtualMemory.c => PeiDxeVirtualMemory.c} | 0
OvmfPkg/Library/BaseMemEncryptSevLib/X64/SecVirtualMemory.c | 80 ++++++++++
7 files changed, 289 insertions(+), 4 deletions(-)
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/DxeMemEncryptSevLib.inf b/OvmfPkg/Library/BaseMemEncryptSevLib/DxeMemEncryptSevLib.inf
index 837db0876184..4480e4cc7c89 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/DxeMemEncryptSevLib.inf
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/DxeMemEncryptSevLib.inf
@@ -31,11 +31,11 @@ [Packages]
[Sources]
DxeMemEncryptSevLibInternal.c
- MemEncryptSevLibInternal.c
+ PeiDxeMemEncryptSevLibInternal.c
[Sources.X64]
X64/MemEncryptSevLib.c
- X64/VirtualMemory.c
+ X64/PeiDxeVirtualMemory.c
X64/VirtualMemory.h
[Sources.IA32]
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLib.inf b/OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLib.inf
index 7c29d14039d6..faabd234e393 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLib.inf
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/PeiMemEncryptSevLib.inf
@@ -31,11 +31,11 @@ [Packages]
[Sources]
PeiMemEncryptSevLibInternal.c
- MemEncryptSevLibInternal.c
+ PeiDxeMemEncryptSevLibInternal.c
[Sources.X64]
X64/MemEncryptSevLib.c
- X64/VirtualMemory.c
+ X64/PeiDxeVirtualMemory.c
X64/VirtualMemory.h
[Sources.IA32]
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/SecMemEncryptSevLib.inf b/OvmfPkg/Library/BaseMemEncryptSevLib/SecMemEncryptSevLib.inf
new file mode 100644
index 000000000000..7cd0111fe47b
--- /dev/null
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/SecMemEncryptSevLib.inf
@@ -0,0 +1,50 @@
+## @file
+# Library provides the helper functions for SEV guest
+#
+# Copyright (c) 2020 Advanced Micro Devices. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#
+##
+
+[Defines]
+ INF_VERSION = 1.25
+ BASE_NAME = SecMemEncryptSevLib
+ FILE_GUID = 046388b4-430e-4e61-88f6-51ea21db2632
+ MODULE_TYPE = BASE
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = MemEncryptSevLib|SEC
+
+#
+# The following information is for reference only and not required by the build
+# tools.
+#
+# VALID_ARCHITECTURES = IA32 X64
+#
+
+[Packages]
+ MdeModulePkg/MdeModulePkg.dec
+ MdePkg/MdePkg.dec
+ OvmfPkg/OvmfPkg.dec
+ UefiCpuPkg/UefiCpuPkg.dec
+
+[Sources]
+ SecMemEncryptSevLibInternal.c
+
+[Sources.X64]
+ X64/MemEncryptSevLib.c
+ X64/SecVirtualMemory.c
+ X64/VirtualMemory.h
+
+[Sources.IA32]
+ Ia32/MemEncryptSevLib.c
+
+[LibraryClasses]
+ BaseLib
+ CpuLib
+ DebugLib
+ PcdLib
+
+[FixedPcd]
+ gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaBase
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c b/OvmfPkg/Library/BaseMemEncryptSevLib/PeiDxeMemEncryptSevLibInternal.c
similarity index 100%
rename from OvmfPkg/Library/BaseMemEncryptSevLib/MemEncryptSevLibInternal.c
rename to OvmfPkg/Library/BaseMemEncryptSevLib/PeiDxeMemEncryptSevLibInternal.c
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/SecMemEncryptSevLibInternal.c b/OvmfPkg/Library/BaseMemEncryptSevLib/SecMemEncryptSevLibInternal.c
new file mode 100644
index 000000000000..56d8f3f3183f
--- /dev/null
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/SecMemEncryptSevLibInternal.c
@@ -0,0 +1,155 @@
+/** @file
+
+ Secure Encrypted Virtualization (SEV) library helper function
+
+ Copyright (c) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemEncryptSevLib.h>
+#include <Library/PcdLib.h>
+#include <Register/Amd/Cpuid.h>
+#include <Register/Amd/Msr.h>
+#include <Register/Cpuid.h>
+#include <Uefi/UefiBaseType.h>
+
+/**
+ Reads and sets the status of SEV features.
+
+ **/
+STATIC
+UINT32
+EFIAPI
+InternalMemEncryptSevStatus (
+ VOID
+ )
+{
+ UINT32 RegEax;
+ CPUID_MEMORY_ENCRYPTION_INFO_EAX Eax;
+ BOOLEAN ReadSevMsr;
+ SEC_SEV_ES_WORK_AREA *SevEsWorkArea;
+
+ ReadSevMsr = FALSE;
+
+ SevEsWorkArea = (SEC_SEV_ES_WORK_AREA *) FixedPcdGet32 (PcdSevEsWorkAreaBase);
+ if (SevEsWorkArea != NULL && SevEsWorkArea->EncryptionMask != 0) {
+ //
+ // The MSR has been read before, so it is safe to read it again and avoid
+ // having to validate the CPUID information.
+ //
+ ReadSevMsr = TRUE;
+ } else {
+ //
+ // Check if memory encryption leaf exist
+ //
+ AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL);
+ if (RegEax >= CPUID_MEMORY_ENCRYPTION_INFO) {
+ //
+ // CPUID Fn8000_001F[EAX] Bit 1 (Sev supported)
+ //
+ AsmCpuid (CPUID_MEMORY_ENCRYPTION_INFO, &Eax.Uint32, NULL, NULL, NULL);
+
+ if (Eax.Bits.SevBit) {
+ ReadSevMsr = TRUE;
+ }
+ }
+ }
+
+ return ReadSevMsr ? AsmReadMsr32 (MSR_SEV_STATUS) : 0;
+}
+
+/**
+ Returns a boolean to indicate whether SEV-ES is enabled.
+
+ @retval TRUE SEV-ES is enabled
+ @retval FALSE SEV-ES is not enabled
+**/
+BOOLEAN
+EFIAPI
+MemEncryptSevEsIsEnabled (
+ VOID
+ )
+{
+ MSR_SEV_STATUS_REGISTER Msr;
+
+ Msr.Uint32 = InternalMemEncryptSevStatus ();
+
+ return Msr.Bits.SevEsBit ? TRUE : FALSE;
+}
+
+/**
+ Returns a boolean to indicate whether SEV is enabled.
+
+ @retval TRUE SEV is enabled
+ @retval FALSE SEV is not enabled
+**/
+BOOLEAN
+EFIAPI
+MemEncryptSevIsEnabled (
+ VOID
+ )
+{
+ MSR_SEV_STATUS_REGISTER Msr;
+
+ Msr.Uint32 = InternalMemEncryptSevStatus ();
+
+ return Msr.Bits.SevBit ? TRUE : FALSE;
+}
+
+/**
+ Returns the SEV encryption mask.
+
+ @return The SEV pagtable encryption mask
+**/
+UINT64
+EFIAPI
+MemEncryptSevGetEncryptionMask (
+ VOID
+ )
+{
+ CPUID_MEMORY_ENCRYPTION_INFO_EBX Ebx;
+ SEC_SEV_ES_WORK_AREA *SevEsWorkArea;
+ UINT64 EncryptionMask;
+
+ SevEsWorkArea = (SEC_SEV_ES_WORK_AREA *) FixedPcdGet32 (PcdSevEsWorkAreaBase);
+ if (SevEsWorkArea != NULL) {
+ EncryptionMask = SevEsWorkArea->EncryptionMask;
+ } else {
+ //
+ // CPUID Fn8000_001F[EBX] Bit 0:5 (memory encryption bit position)
+ //
+ AsmCpuid (CPUID_MEMORY_ENCRYPTION_INFO, NULL, &Ebx.Uint32, NULL, NULL);
+ EncryptionMask = LShiftU64 (1, Ebx.Bits.PtePosBits);
+ }
+
+ return EncryptionMask;
+}
+
+/**
+ Locate the page range that covers the initial (pre-SMBASE-relocation) SMRAM
+ Save State Map.
+
+ @param[out] BaseAddress The base address of the lowest-address page that
+ covers the initial SMRAM Save State Map.
+
+ @param[out] NumberOfPages The number of pages in the page range that covers
+ the initial SMRAM Save State Map.
+
+ @retval RETURN_SUCCESS BaseAddress and NumberOfPages have been set on
+ output.
+
+ @retval RETURN_UNSUPPORTED SMM is unavailable.
+**/
+RETURN_STATUS
+EFIAPI
+MemEncryptSevLocateInitialSmramSaveStateMapPages (
+ OUT UINTN *BaseAddress,
+ OUT UINTN *NumberOfPages
+ )
+{
+ return RETURN_UNSUPPORTED;
+}
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
similarity index 100%
rename from OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.c
rename to OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SecVirtualMemory.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SecVirtualMemory.c
new file mode 100644
index 000000000000..5c337ea0b820
--- /dev/null
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SecVirtualMemory.c
@@ -0,0 +1,80 @@
+/** @file
+
+ Virtual Memory Management Services to set or clear the memory encryption bit
+
+ Copyright (c) 2020, AMD Incorporated. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/CpuLib.h>
+#include <Library/MemEncryptSevLib.h>
+
+#include "VirtualMemory.h"
+
+/**
+ This function clears memory encryption bit for the memory region specified by
+ PhysicalAddress and Length from the current page table context.
+
+ @param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
+ current CR3)
+ @param[in] PhysicalAddress The physical address that is the start
+ address of a memory region.
+ @param[in] Length The length of memory region
+ @param[in] Flush Flush the caches before applying the
+ encryption mask
+
+ @retval RETURN_SUCCESS The attributes were cleared for the
+ memory region.
+ @retval RETURN_INVALID_PARAMETER Number of pages is zero.
+ @retval RETURN_UNSUPPORTED Clearing the memory encyrption attribute
+ is not supported
+**/
+RETURN_STATUS
+EFIAPI
+InternalMemEncryptSevSetMemoryDecrypted (
+ IN PHYSICAL_ADDRESS Cr3BaseAddress,
+ IN PHYSICAL_ADDRESS PhysicalAddress,
+ IN UINTN Length,
+ IN BOOLEAN Flush
+ )
+{
+ //
+ // This function is not available during SEC.
+ //
+ return RETURN_UNSUPPORTED;
+}
+
+/**
+ This function sets memory encryption bit for the memory region specified by
+ PhysicalAddress and Length from the current page table context.
+
+ @param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
+ current CR3)
+ @param[in] PhysicalAddress The physical address that is the start
+ address of a memory region.
+ @param[in] Length The length of memory region
+ @param[in] Flush Flush the caches before applying the
+ encryption mask
+
+ @retval RETURN_SUCCESS The attributes were set for the memory
+ region.
+ @retval RETURN_INVALID_PARAMETER Number of pages is zero.
+ @retval RETURN_UNSUPPORTED Setting the memory encyrption attribute
+ is not supported
+**/
+RETURN_STATUS
+EFIAPI
+InternalMemEncryptSevSetMemoryEncrypted (
+ IN PHYSICAL_ADDRESS Cr3BaseAddress,
+ IN PHYSICAL_ADDRESS PhysicalAddress,
+ IN UINTN Length,
+ IN BOOLEAN Flush
+ )
+{
+ //
+ // This function is not available during SEC.
+ //
+ return RETURN_UNSUPPORTED;
+}
--
2.30.0
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