MemoryProtectionTestApp: Separate Reset Method Init to Arch Specific …

…Files (#376)

## Description

The reset test method is not supported on ARM platforms currently
(support will be added later, but it's not high priority because this
test method often takes 40+ minutes). This PR separates the
initialization of this testing method to architecture specific logic so
the test method is not attempted on ARM platforms.

This also fixes a build error on ARM platforms caused by
DefaultExceptionHandlerLib being included (which does not support
UEFI_APPLICATION without a MU override).

- [x] Impacts functionality?
- **Functionality** - Does the change ultimately impact how firmware
functions?
- Examples: Add a new library, publish a new PPI, update an algorithm,
...
- [ ] Impacts security?
- **Security** - Does the change have a direct security impact on an
application,
    flow, or firmware?
  - Examples: Crypto algorithm change, buffer overflow fix, parameter
    validation improvement, ...
- [ ] Breaking change?
- **Breaking change** - Will anyone consuming this change experience a
break
    in build or boot behavior?
- Examples: Add a new library class, move a module to a different repo,
call
    a function in a new library class in a pre-existing module, ...
- [ ] Includes tests?
  - **Tests** - Does the change include any explicit test code?
  - Examples: Unit tests, integration tests, robot tests, ...
- [ ] Includes documentation?
- **Documentation** - Does the change contain explicit documentation
additions
    outside direct code modifications (and comments)?
- Examples: Update readme file, add feature readme file, link to
documentation
    on an a separate Web page, ...

## How This Was Tested

Running the updated test app on Q35 and SBSA

## Integration Instructions

N/A

UefiTestingPkg/FunctionalSystemTests/MemoryProtectionTest/App/AArch64/AArch64Functions.c

@@ -0,0 +1,46 @@
+/** @file
+
+Copyright (C) Microsoft Corporation. All rights reserved.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+
+#include <Library/DebugLib.h>
+#include <Library/UnitTestLib.h>
+
+/**
+  Registers the interrupt handler which will be invoked when a page fault occurs.
+
+  @retval     EFI_SUCCESS         Interrupt handler successfully installed
+  @retval     EFI_UNSUPPORTED     Installing the interrupt handler is not supported.
+  @retval     others              Error occurred during installation.
+**/
+EFI_STATUS
+EFIAPI
+RegisterMemoryProtectionTestAppInterruptHandler (
+  VOID
+  )
+{
+  // TODO: Add support for reset test method on Arm
+  return EFI_UNSUPPORTED;
+}
+
+/**
+  Checks if the hardware NX protection is enabled.
+
+  @param[in]  Context   The unit test context.
+
+  @retval     UNIT_TEST_PASSED    Hardware NX protection is enabled.
+  @retval     others              Hardware NX protection is not enabled.
+**/
+UNIT_TEST_STATUS
+EFIAPI
+UefiHardwareNxProtectionEnabled (
+  IN UNIT_TEST_CONTEXT  Context
+  )
+{
+  // ARM UEFI only has Stage 1 translation, so the FEAT XNX configuration bit does not apply.
+  return UNIT_TEST_PASSED;
+}

UefiTestingPkg/FunctionalSystemTests/MemoryProtectionTest/App/ArchSpecificFunctions.h

@@ -0,0 +1,39 @@
+/** @file -- ArchSpecificFunctions.h
+Shared definition of the method between x64 and ARM.
+
+Copyright (C) Microsoft Corporation. All rights reserved.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef ARCH_SPECIFIC_FUNCTIONS_H_
+#define ARCH_SPECIFIC_FUNCTIONS_H_
+
+/**
+  Registers the interrupt handler which will be invoked when a page fault occurs.
+
+  @retval     EFI_SUCCESS         Interrupt handler successfully installed
+  @retval     EFI_UNSUPPORTED     Installing the interrupt handler is not supported.
+  @retval     others              Error occurred during installation.
+**/
+EFI_STATUS
+EFIAPI
+RegisterMemoryProtectionTestAppInterruptHandler (
+  VOID
+  );
+
+/**
+  Checks if the hardware NX protection is enabled.
+
+  @param[in]  Context   The unit test context.
+
+  @retval     UNIT_TEST_PASSED    Hardware NX protection is enabled.
+  @retval     others              Hardware NX protection is not enabled.
+**/
+UNIT_TEST_STATUS
+EFIAPI
+UefiHardwareNxProtectionEnabled (
+  IN UNIT_TEST_CONTEXT  Context
+  );
+
+#endif // ARCH_SPECIFIC_FUNCTIONS_H_

UefiTestingPkg/FunctionalSystemTests/MemoryProtectionTest/App/MemoryProtectionTestApp.c

@@ -9,7 +9,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 
 #include <Uefi.h>
 
-#include <Protocol/Cpu.h>
+#include <Protocol/DebugSupport.h>
 #include <Protocol/SmmCommunication.h>
 #include <Protocol/MemoryProtectionNonstopMode.h>
 #include <Protocol/MemoryProtectionDebug.h>
@@ -31,8 +31,6 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Library/UnitTestBootLib.h>
 #include <Library/MemoryAllocationLib.h>
 #include <Library/UefiRuntimeServicesTableLib.h>
-#include <Register/ArchitecturalMsr.h>
-#include <Library/ResetSystemLib.h>
 #include <Library/HobLib.h>
 #include <Library/ExceptionPersistenceLib.h>
 
@@ -41,7 +39,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Guid/MmMemoryProtectionSettings.h>
 
 #include "../MemoryProtectionTestCommon.h"
-#include "UefiHardwareNxProtectionStub.h"
+#include "ArchSpecificFunctions.h"
 
 #define UNIT_TEST_APP_NAME                 "Memory Protection Test"
 #define UNIT_TEST_APP_VERSION              "2.0"
@@ -56,7 +54,6 @@ UINTN                                    mPiSmmCommonCommBufferSize;
 MM_MEMORY_PROTECTION_SETTINGS            mMmMps;
 DXE_MEMORY_PROTECTION_SETTINGS           mDxeMps;
 VOID                                     *mPiSmmCommonCommBufferAddress = NULL;
-EFI_CPU_ARCH_PROTOCOL                    *mCpu                          = NULL;
 MEMORY_PROTECTION_NONSTOP_MODE_PROTOCOL  *mNonstopModeProtocol          = NULL;
 MEMORY_PROTECTION_DEBUG_PROTOCOL         *mMemoryProtectionProtocol     = NULL;
 EFI_MEMORY_ATTRIBUTE_PROTOCOL            *mMemoryAttributeProtocol      = NULL;
@@ -286,27 +283,6 @@ PopulateCpuMpDebugProtocol (
   return gBS->LocateProtocol (&gCpuMpDebugProtocolGuid, NULL, (VOID **)&mCpuMpDebugProtocol);
 }
 
-/**
-  Resets the system on interrupt
-
-  @param  InterruptType    Defines the type of interrupt or exception that
-                           occurred on the processor.This parameter is processor architecture specific.
-  @param  SystemContext    A pointer to the processor context when
-                           the interrupt occurred on the processor.
-**/
-VOID
-EFIAPI
-InterruptHandler (
-  IN EFI_EXCEPTION_TYPE  InterruptType,
-  IN EFI_SYSTEM_CONTEXT  SystemContext
-  )
-{
-  // Avoid using runtime services to reset the system because doing so will raise the TPL level
-  // when it is already on TPL_HIGH. HwResetSystemLib is used here instead to perform a bare-metal reset
-  // and sidestep this issue.
-  ResetWarm ();
-}
-
 /**
   This helper function returns EFI_SUCCESS if the Nonstop protocol is installed.
 
@@ -2475,11 +2451,7 @@ DetermineTestMethod (
       }
 
     case MemoryProtectionTestReset:
-      // Uninstall the existing page fault handler
-      mCpu->RegisterInterruptHandler (mCpu, EXCEPT_IA32_PAGE_FAULT, NULL);
-
-      // Install an interrupt handler to reboot on page faults.
-      if (!EFI_ERROR (mCpu->RegisterInterruptHandler (mCpu, EXCEPT_IA32_PAGE_FAULT, InterruptHandler))) {
+      if (!EFI_ERROR (RegisterMemoryProtectionTestAppInterruptHandler ())) {
         DeterminedTestingMethod = MemoryProtectionTestReset;
         break;
       }
@@ -2581,13 +2553,6 @@ MemoryProtectionTestAppEntryPoint (
   Status = FetchMemoryProtectionHobEntries ();
   ASSERT_EFI_ERROR (Status);
 
-  // Find the CPU Architecture Protocol
-  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&mCpu);
-  if (EFI_ERROR (Status)) {
-    DEBUG ((DEBUG_ERROR, "Failed to locate gEfiCpuArchProtocolGuid. Status = %r\n", Status));
-    goto EXIT;
-  }
-
   // Set up the test framework for running the tests.
   Status = InitUnitTestFramework (&Fw, UNIT_TEST_APP_NAME, gEfiCallerBaseName, UNIT_TEST_APP_VERSION);
   if (EFI_ERROR (Status)) {

UefiTestingPkg/FunctionalSystemTests/MemoryProtectionTest/App/MemoryProtectionTestApp.inf

@@ -24,13 +24,10 @@
   MemoryProtectionTestApp.c
 
 [Sources.X64]
-  X64/UefiHardwareNxProtection.c
-
-[Sources.ARM]
-  Arm/UefiHardwareNxProtection.c
+  X64/X64Functions.c
 
 [Sources.AARCH64]
-  Arm/UefiHardwareNxProtection.c
+  AArch64/AArch64Functions.c
 
 [Packages]
   MdePkg/MdePkg.dec
@@ -52,11 +49,12 @@
   BaseLib
   ShellLib
   UefiLib
-  CpuExceptionHandlerLib
-  HwResetSystemLib
   HobLib
   ExceptionPersistenceLib
 
+[LibraryClasses.X64]
+  HwResetSystemLib
+
 [Guids]
   gMemoryProtectionExceptionHandlerGuid               ## CONSUMES
   gEfiHobMemoryAllocStackGuid                         ## CONSUMES

UefiTestingPkg/FunctionalSystemTests/MemoryProtectionTest/App/X64/X64Functions.c

@@ -0,0 +1,92 @@
+/** @file
+
+Copyright (c) Microsoft Corporation. All rights reserved.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Register/ArchitecturalMsr.h>
+#include <Library/UnitTestLib.h>
+#include <Library/ResetSystemLib.h>
+#include <Protocol/Cpu.h>
+#include <Library/UefiBootServicesTableLib.h>
+
+/**
+  Resets the system on interrupt
+
+  @param  InterruptType    Defines the type of interrupt or exception that
+                           occurred on the processor.This parameter is processor architecture specific.
+  @param  SystemContext    A pointer to the processor context when
+                           the interrupt occurred on the processor.
+**/
+VOID
+EFIAPI
+InterruptHandler (
+  IN EFI_EXCEPTION_TYPE  InterruptType,
+  IN EFI_SYSTEM_CONTEXT  SystemContext
+  )
+{
+  // Avoid using runtime services to reset the system because doing so will raise the TPL level
+  // when it is already on TPL_HIGH. HwResetSystemLib is used here instead to perform a bare-metal reset
+  // and sidestep this issue.
+  ResetWarm ();
+}
+
+/**
+  Registers the interrupt handler which will be invoked when a page fault occurs.
+
+  @retval     EFI_SUCCESS         Interrupt handler successfully installed
+  @retval     EFI_UNSUPPORTED     Installing the interrupt handler is not supported.
+  @retval     others              Error occurred during installation.
+**/
+EFI_STATUS
+EFIAPI
+RegisterMemoryProtectionTestAppInterruptHandler (
+  VOID
+  )
+{
+  EFI_CPU_ARCH_PROTOCOL  *CpuProtocol = NULL;
+  EFI_STATUS             Status;
+
+  // Find the CPU Architecture Protocol
+  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **)&CpuProtocol);
+
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "Failed to locate gEfiCpuArchProtocolGuid. Status = %r\n", Status));
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Uninstall the existing page fault handler
+  CpuProtocol->RegisterInterruptHandler (CpuProtocol, EXCEPT_IA32_PAGE_FAULT, NULL);
+
+  return CpuProtocol->RegisterInterruptHandler (CpuProtocol, EXCEPT_IA32_PAGE_FAULT, InterruptHandler);
+}
+
+/**
+  Checks if the hardware NX protection is enabled.
+
+  @param[in]  Context   The unit test context.
+
+  @retval     UNIT_TEST_PASSED    Hardware NX protection is enabled.
+  @retval     others              Hardware NX protection is not enabled.
+**/
+UNIT_TEST_STATUS
+EFIAPI
+UefiHardwareNxProtectionEnabled (
+  IN UNIT_TEST_CONTEXT  Context
+  )
+{
+  MSR_IA32_EFER_REGISTER  Efer;
+
+  Efer.Uint64 = AsmReadMsr64 (MSR_IA32_EFER);
+  if (Efer.Bits.NXE == 1) {
+    return UNIT_TEST_PASSED;
+  }
+
+  UT_LOG_WARNING ("Efer set as 0x%x\n", Efer);
+  return UNIT_TEST_ERROR_TEST_FAILED;
+}