diff options
| -rw-r--r-- | OvmfPkg/PlatformPei/ClearCache.c | 117 | ||||
| -rw-r--r-- | OvmfPkg/PlatformPei/Platform.c | 1 | ||||
| -rw-r--r-- | OvmfPkg/PlatformPei/Platform.h | 5 | ||||
| -rw-r--r-- | OvmfPkg/PlatformPei/PlatformPei.inf | 2 |
4 files changed, 125 insertions, 0 deletions
diff --git a/OvmfPkg/PlatformPei/ClearCache.c b/OvmfPkg/PlatformPei/ClearCache.c new file mode 100644 index 0000000000..7d15fd925c --- /dev/null +++ b/OvmfPkg/PlatformPei/ClearCache.c @@ -0,0 +1,117 @@ +/**@file
+ Install a callback to clear cache on all processors.
+ This is for conformance with the TCG "Platform Reset Attack Mitigation
+ Specification". Because clearing the CPU caches at boot doesn't impact
+ performance significantly, do it unconditionally, for simplicity's
+ sake.
+
+ Copyright (C) 2018, Red Hat, Inc.
+
+ 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 <Library/CacheMaintenanceLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PeiServicesLib.h>
+#include <Ppi/MpServices.h>
+
+#include "Platform.h"
+
+/**
+ Invalidate data & instruction caches.
+ All APs execute this function in parallel. The BSP executes the function
+ separately.
+
+ @param[in,out] WorkSpace Pointer to the input/output argument workspace
+ shared by all processors.
+**/
+STATIC
+VOID
+EFIAPI
+ClearCache (
+ IN OUT VOID *WorkSpace
+ )
+{
+ WriteBackInvalidateDataCache ();
+ InvalidateInstructionCache ();
+}
+
+/**
+ Notification function called when EFI_PEI_MP_SERVICES_PPI becomes available.
+
+ @param[in] PeiServices Indirect reference to the PEI Services Table.
+ @param[in] NotifyDescriptor Address of the notification descriptor data
+ structure.
+ @param[in] Ppi Address of the PPI that was installed.
+
+ @return Status of the notification. The status code returned from this
+ function is ignored.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+ClearCacheOnMpServicesAvailable (
+ IN EFI_PEI_SERVICES **PeiServices,
+ IN EFI_PEI_NOTIFY_DESCRIPTOR *NotifyDescriptor,
+ IN VOID *Ppi
+ )
+{
+ EFI_PEI_MP_SERVICES_PPI *MpServices;
+ EFI_STATUS Status;
+
+ DEBUG ((DEBUG_INFO, "%a: %a\n", gEfiCallerBaseName, __FUNCTION__));
+
+ //
+ // Clear cache on all the APs in parallel.
+ //
+ MpServices = Ppi;
+ Status = MpServices->StartupAllAPs (
+ (CONST EFI_PEI_SERVICES **)PeiServices,
+ MpServices,
+ ClearCache, // Procedure
+ FALSE, // SingleThread
+ 0, // TimeoutInMicroSeconds: inf.
+ NULL // ProcedureArgument
+ );
+ if (EFI_ERROR (Status) && Status != EFI_NOT_STARTED) {
+ DEBUG ((DEBUG_ERROR, "%a: StartupAllAps(): %r\n", __FUNCTION__, Status));
+ return Status;
+ }
+
+ //
+ // Now clear cache on the BSP too.
+ //
+ ClearCache (NULL);
+ return EFI_SUCCESS;
+}
+
+//
+// Notification object for registering the callback, for when
+// EFI_PEI_MP_SERVICES_PPI becomes available.
+//
+STATIC CONST EFI_PEI_NOTIFY_DESCRIPTOR mMpServicesNotify = {
+ EFI_PEI_PPI_DESCRIPTOR_NOTIFY_CALLBACK | // Flags
+ EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,
+ &gEfiPeiMpServicesPpiGuid, // Guid
+ ClearCacheOnMpServicesAvailable // Notify
+};
+
+VOID
+InstallClearCacheCallback (
+ VOID
+ )
+{
+ EFI_STATUS Status;
+
+ Status = PeiServicesNotifyPpi (&mMpServicesNotify);
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_ERROR, "%a: failed to set up MP Services callback: %r\n",
+ __FUNCTION__, Status));
+ }
+}
diff --git a/OvmfPkg/PlatformPei/Platform.c b/OvmfPkg/PlatformPei/Platform.c index 5a78668126..22139a64cb 100644 --- a/OvmfPkg/PlatformPei/Platform.c +++ b/OvmfPkg/PlatformPei/Platform.c @@ -672,6 +672,7 @@ InitializePlatform ( NoexecDxeInitialization ();
}
+ InstallClearCacheCallback ();
AmdSevInitialize ();
MiscInitialization ();
InstallFeatureControlCallback ();
diff --git a/OvmfPkg/PlatformPei/Platform.h b/OvmfPkg/PlatformPei/Platform.h index f942e61bb4..b12a5c1f5f 100644 --- a/OvmfPkg/PlatformPei/Platform.h +++ b/OvmfPkg/PlatformPei/Platform.h @@ -83,6 +83,11 @@ InstallFeatureControlCallback ( VOID
);
+VOID
+InstallClearCacheCallback (
+ VOID
+ );
+
EFI_STATUS
InitializeXen (
VOID
diff --git a/OvmfPkg/PlatformPei/PlatformPei.inf b/OvmfPkg/PlatformPei/PlatformPei.inf index 9c5ad9961c..5c8dd0fe6d 100644 --- a/OvmfPkg/PlatformPei/PlatformPei.inf +++ b/OvmfPkg/PlatformPei/PlatformPei.inf @@ -30,6 +30,7 @@ [Sources]
AmdSev.c
+ ClearCache.c
Cmos.c
Cmos.h
FeatureControl.c
@@ -54,6 +55,7 @@ [LibraryClasses]
BaseLib
+ CacheMaintenanceLib
DebugLib
HobLib
IoLib
|