From: Min M Xu <min.m...@intel.com>
There are 2 functions added for EmuVariableNvStore:
- PlatformReserveEmuVariableNvStore
- PlatformInitEmuVariableNvStore
PlatformReserveEmuVariableNvStore allocate storage for NV variables early
on so it will be at a consistent address.
PlatformInitEmuVariableNvStore copies the content in
PcdOvmfFlashNvStorageVariableBase to the storage allocated by
PlatformReserveEmuVariableNvStore. This is used in the case that OVMF is
launched with -bios parameter. Because in that situation UEFI variables
will be partially emulated, and non-volatile variables may lose their
contents after a reboot. This makes the secure boot feature not working.
Cc: Erdem Aktas <erdemak...@google.com>
Cc: James Bottomley <j...@linux.ibm.com> [jejb]
Cc: Jiewen Yao <jiewen....@intel.com> [jyao1]
Cc: Tom Lendacky <thomas.lenda...@amd.com> [tlendacky]
Cc: Gerd Hoffmann <kra...@redhat.com>
Signed-off-by: Min Xu <min.m...@intel.com>
---
OvmfPkg/Include/Library/PlatformInitLib.h | 34 ++++++++
OvmfPkg/Library/PlatformInitLib/Platform.c | 77 +++++++++++++++++++
.../PlatformInitLib/PlatformInitLib.inf | 2 +
3 files changed, 113 insertions(+)
diff --git a/OvmfPkg/Include/Library/PlatformInitLib.h
b/OvmfPkg/Include/Library/PlatformInitLib.h
index a3acfb1fb196..3a84a56be3c1 100644
--- a/OvmfPkg/Include/Library/PlatformInitLib.h
+++ b/OvmfPkg/Include/Library/PlatformInitLib.h
@@ -251,4 +251,38 @@ TdxValidateCfv (
IN UINT32 TdxCfvSize
);
+/**
+ Allocate storage for NV variables early on so it will be
+ at a consistent address. Since VM memory is preserved
+ across reboots, this allows the NV variable storage to survive
+ a VM reboot.
+
+ *
+ * @retval VOID* The pointer to the storage for NV Variables
+ */
+VOID *
+EFIAPI
+PlatformReserveEmuVariableNvStore (
+ VOID
+ );
+
+/**
+ When OVMF is lauched with -bios parameter, UEFI variables will be
+ partially emulated, and non-volatile variables may lose their contents
+ after a reboot. This makes the secure boot feature not working.
+
+ This function is used to initialize the EmuVariableNvStore
+ with the conent in PcdOvmfFlashNvStorageVariableBase.
+
+ @param[in] EmuVariableNvStore - A pointer to EmuVariableNvStore
+
+ @retval EFI_SUCCESS - Successfully init the EmuVariableNvStore
+ @retval Others - As the error code indicates
+ */
+EFI_STATUS
+EFIAPI
+PlatformInitEmuVariableNvStore (
+ IN VOID *EmuVariableNvStore
+ );
+
#endif // PLATFORM_INIT_LIB_H_
diff --git a/OvmfPkg/Library/PlatformInitLib/Platform.c
b/OvmfPkg/Library/PlatformInitLib/Platform.c
index c3d34e43af5a..194768379f2b 100644
--- a/OvmfPkg/Library/PlatformInitLib/Platform.c
+++ b/OvmfPkg/Library/PlatformInitLib/Platform.c
@@ -25,6 +25,7 @@
#include <IndustryStandard/Pci22.h>
#include <IndustryStandard/Q35MchIch9.h>
#include <IndustryStandard/QemuCpuHotplug.h>
+#include <Library/MemoryAllocationLib.h>
#include <Library/QemuFwCfgLib.h>
#include <Library/QemuFwCfgS3Lib.h>
#include <Library/QemuFwCfgSimpleParserLib.h>
@@ -576,3 +577,79 @@ PlatformMaxCpuCountInitialization (
PlatformInfoHob->PcdCpuMaxLogicalProcessorNumber = MaxCpuCount;
PlatformInfoHob->PcdCpuBootLogicalProcessorNumber = BootCpuCount;
}
+
+/**
+ Allocate storage for NV variables early on so it will be
+ at a consistent address. Since VM memory is preserved
+ across reboots, this allows the NV variable storage to survive
+ a VM reboot.
+
+ *
+ * @retval VOID* The pointer to the storage for NV Variables
+ */
+VOID *
+EFIAPI
+PlatformReserveEmuVariableNvStore (
+ VOID
+ )
+{
+ VOID *VariableStore;
+ UINT32 VarStoreSize;
+
+ VarStoreSize = 2 * PcdGet32 (PcdFlashNvStorageFtwSpareSize);
+ //
+ // Allocate storage for NV variables early on so it will be
+ // at a consistent address. Since VM memory is preserved
+ // across reboots, this allows the NV variable storage to survive
+ // a VM reboot.
+ //
+ VariableStore =
+ AllocateRuntimePages (
+ EFI_SIZE_TO_PAGES (VarStoreSize)
+ );
+ DEBUG ((
+ DEBUG_INFO,
+ "Reserved variable store memory: 0x%p; size: %dkb\n",
+ VariableStore,
+ VarStoreSize / 1024
+ ));
+
+ return VariableStore;
+}
+
+/**
+ When OVMF is lauched with -bios parameter, UEFI variables will be
+ partially emulated, and non-volatile variables may lose their contents
+ after a reboot. This makes the secure boot feature not working.
+
+ This function is used to initialize the EmuVariableNvStore
+ with the conent in PcdOvmfFlashNvStorageVariableBase.
+
+ @param[in] EmuVariableNvStore - A pointer to EmuVariableNvStore
+
+ @retval EFI_SUCCESS - Successfully init the EmuVariableNvStore
+ @retval Others - As the error code indicates
+ */
+EFI_STATUS
+EFIAPI
+PlatformInitEmuVariableNvStore (
+ IN VOID *EmuVariableNvStore
+ )
+{
+ UINT8 *Base;
+ UINT32 Size;
+ UINT32 EmuVariableNvStoreSize;
+
+ EmuVariableNvStoreSize = 2 * PcdGet32 (PcdFlashNvStorageFtwSpareSize);
+ if ((EmuVariableNvStore == NULL) || (EmuVariableNvStoreSize == 0)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Base = (UINT8 *)(UINTN)PcdGet32 (PcdOvmfFlashNvStorageVariableBase);
+ Size = (UINT32)PcdGet32 (PcdFlashNvStorageVariableSize);
+ ASSERT (Size < EmuVariableNvStoreSize);
+
+ CopyMem (EmuVariableNvStore, Base, Size);
+
+ return EFI_SUCCESS;
+}
diff --git a/OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf
b/OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf
index d2fa2d998df8..fec1f8f24314 100644
--- a/OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf
+++ b/OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf
@@ -47,6 +47,7 @@
HobLib
QemuFwCfgLib
QemuFwCfgSimpleParserLib
+ MemoryAllocationLib
MtrrLib
PcdLib
PciLib
@@ -96,6 +97,7 @@
gUefiOvmfPkgTokenSpaceGuid.PcdGuidedExtractHandlerTableSize
gUefiOvmfPkgTokenSpaceGuid.PcdTdxAcceptPageSize
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageVariableBase
[FeaturePcd]
gEfiMdeModulePkgTokenSpaceGuid.PcdDxeIplSwitchToLongMode
--
2.29.2.windows.2
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