diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index f9f718087893..c726d115939a 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -948,12 +948,13 @@ static inline int get_hpet_devid(int id)
 }
 
 enum amd_iommu_intr_mode_type {
-	AMD_IOMMU_GUEST_IR_LEGACY,
-
-	/* This mode is not visible to users. It is used when
-	 * we cannot fully enable vAPIC and fallback to only support
-	 * legacy interrupt remapping via 128-bit IRTE.
+	/*
+	 * The legacy format mode is not visible to users to prevent the user
+	 * from crashing x2APIC systems, which for all intents and purposes
+	 * require 128-bit IRTEs.   The legacy format will be forced as needed
+	 * when hardware doesn't support 128-bit IRTEs.
 	 */
+	AMD_IOMMU_GUEST_IR_LEGACY,
 	AMD_IOMMU_GUEST_IR_LEGACY_GA,
 	AMD_IOMMU_GUEST_IR_VAPIC,
 };