diff --git a/OvmfPkg/Library/SmmRelocationLib/SmmRelocationLib.c b/OvmfPkg/Library/SmmRelocationLib/SmmRelocationLib.c
index 4f6b513c72..9a11b44e2f 100644
--- a/OvmfPkg/Library/SmmRelocationLib/SmmRelocationLib.c
+++ b/OvmfPkg/Library/SmmRelocationLib/SmmRelocationLib.c
@@ -274,10 +274,10 @@ InitSmmIdt (
   CONST EFI_PEI_SERVICES  **PeiServices;
 
   //
-  // There are 32 (not 255) entries in it since only processor
-  // generated exceptions will be handled.
+  // Populate 256 entries to ensure that a known state occurs
+  // for all possible exception vectors.
   //
-  gcSmmInitIdtr.Limit = (sizeof (IA32_IDT_GATE_DESCRIPTOR) * 32) - 1;
+  gcSmmInitIdtr.Limit = (sizeof (IA32_IDT_GATE_DESCRIPTOR) * X86_CPU_INTERRUPT_NUM) - 1;
 
   //
   // Allocate for IDT.
diff --git a/OvmfPkg/Sec/SecMain.c b/OvmfPkg/Sec/SecMain.c
index d13a948509..60a00ce531 100644
--- a/OvmfPkg/Sec/SecMain.c
+++ b/OvmfPkg/Sec/SecMain.c
@@ -33,11 +33,9 @@
 #include <Register/Intel/Cpuid.h>
 #include "AmdSev.h"
 
-#define SEC_IDT_ENTRY_COUNT  34
-
 typedef struct _SEC_IDT_TABLE {
   EFI_PEI_SERVICES            *PeiService;
-  IA32_IDT_GATE_DESCRIPTOR    IdtTable[SEC_IDT_ENTRY_COUNT];
+  IA32_IDT_GATE_DESCRIPTOR    IdtTable[X86_CPU_INTERRUPT_NUM];
 } SEC_IDT_TABLE;
 
 VOID
@@ -844,7 +842,7 @@ SecCoreStartupWithStack (
   //
   IdtTableInStack.PeiService = NULL;
 
-  for (Index = 0; Index < SEC_IDT_ENTRY_COUNT; Index++) {
+  for (Index = 0; Index < X86_CPU_INTERRUPT_NUM; Index++) {
     //
     // Declare the local variables that actually move the data elements as
     // volatile to prevent the optimizer from replacing this function with
@@ -889,9 +887,10 @@ SecCoreStartupWithStack (
 
   if (!SevEsIsEnabled ()) {
     //
-    // For non SEV-ES guests, just load the IDTR.
+    // For non SEV-ES guests, now load the IDTR and initialize the exception handlers.
     //
     AsmWriteIdtr (&IdtDescriptor);
+    InitializeCpuExceptionHandlers (NULL);
   } else {
     //
     // Under SEV-ES, the hypervisor can't modify CR0 and so can't enable