OvmfPkg: QemuFlashFvbServicesRuntimeDxe: adhere to -D SMM_REQUIRE

When the user requires "security" by passing -D SMM_REQUIRE, and
consequently by setting PcdSmmSmramRequire, enforce flash-based variables.

Furthermore, add two ASSERT()s to catch if the wrong module were pulled
into the build.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19063 6f19259b-4bc3-4df7-8a09-765794883524

OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FvbServicesRuntimeDxe.inf

@@ -85,6 +85,8 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashVariablesEnable
 
+[FeaturePcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire
 
 [Depex]
   TRUE

OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FvbServicesSmm.inf

@@ -84,6 +84,8 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashVariablesEnable
 
+[FeaturePcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire
 
 [Depex]
   TRUE

OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockServiceDxe.c

@@ -17,6 +17,7 @@
 #include <Guid/EventGroup.h>
 #include <Library/DebugLib.h>
 #include <Library/DevicePathLib.h>
+#include <Library/PcdLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/UefiRuntimeLib.h>
 #include <Protocol/DevicePath.h>
@@ -34,6 +35,8 @@ InstallProtocolInterfaces (
   EFI_HANDLE                         FwbHandle;
   EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL *OldFwbInterface;
 
+  ASSERT (!FeaturePcdGet (PcdSmmSmramRequire));
+
   //
   // Find a handle with a matching device path that has supports FW Block
   // protocol

OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockServiceSmm.c

@@ -15,6 +15,7 @@
 **/
 
 #include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
 #include <Library/SmmServicesTableLib.h>
 #include <Protocol/DevicePath.h>
 #include <Protocol/SmmFirmwareVolumeBlock.h>
@@ -29,6 +30,8 @@ InstallProtocolInterfaces (
   EFI_HANDLE FvbHandle;
   EFI_STATUS Status;
 
+  ASSERT (FeaturePcdGet (PcdSmmSmramRequire));
+
   //
   // There is no SMM service that can install multiple protocols in the SMM
   // protocol database in one go.

OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlash.c

@@ -245,6 +245,7 @@ QemuFlashInitialize (
   mFdBlockCount = PcdGet32 (PcdOvmfFirmwareFdSize) / mFdBlockSize;
 
   if (!QemuFlashDetected ()) {
+    ASSERT (!FeaturePcdGet (PcdSmmSmramRequire));
     return EFI_WRITE_PROTECTED;
   }