OvmfPkg/VirtMmCommunicationDxe: stop on init failure

Print an error and stop in case VirtMmCommunicationDxe
initialization fails.

Signed-off-by: Gerd Hoffmann <[email protected]>

Author: kraxel

OvmfPkg/VirtMmCommunicationDxe/VirtMmCommunication.c

@@ -396,5 +396,15 @@ VirtMmCommunication2Initialize (
   FreePages (mCommunicateBuffer, EFI_SIZE_TO_PAGES (MAX_BUFFER_SIZE));
 
 ReturnErrorStatus:
+  if (FeaturePcdGet (PcdQemuVarsRequire)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "ERROR: qemu uefi variable service is not available, use \n"
+      "  'qemu-system-x86_64 -device uefi-vars-x64' or\n"
+      "  'qemu-system-aarch64 -device uefi-vars-sysbus'\n"
+      ));
+    CpuDeadLoop ();
+  }
+
   return EFI_INVALID_PARAMETER;
 }

OvmfPkg/VirtMmCommunicationDxe/VirtMmCommunication.inf

@@ -52,6 +52,7 @@
 [FeaturePcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdEnableVariableRuntimeCache           ## CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdVariableCollectStatistics            ## CONSUMES
+  gUefiOvmfPkgTokenSpaceGuid.PcdQemuVarsRequire                          ## CONSUMES
 
 [Protocols]
   gEfiMmCommunication2ProtocolGuid              ## PRODUCES