diff --git a/src/conf/domain_validate.c b/src/conf/domain_validate.c
index d4d72037d5..88205c64e0 100644
--- a/src/conf/domain_validate.c
+++ b/src/conf/domain_validate.c
@@ -2632,8 +2632,20 @@ static int
 virDomainIOMMUDefValidate(const virDomainIOMMUDef *iommu)
 {
     switch (iommu->model) {
-    case VIR_DOMAIN_IOMMU_MODEL_INTEL:
     case VIR_DOMAIN_IOMMU_MODEL_SMMUV3:
+        if (iommu->intremap != VIR_TRISTATE_SWITCH_ABSENT ||
+            iommu->caching_mode != VIR_TRISTATE_SWITCH_ABSENT ||
+            iommu->eim != VIR_TRISTATE_SWITCH_ABSENT ||
+            iommu->iotlb != VIR_TRISTATE_SWITCH_ABSENT ||
+            iommu->aw_bits != 0) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("iommu model '%s' doesn't support additional attributes"),
+                           virDomainIOMMUModelTypeToString(iommu->model));
+            return -1;
+        }
+        G_GNUC_FALLTHROUGH;
+
+    case VIR_DOMAIN_IOMMU_MODEL_INTEL:
         if (iommu->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE) {
             virReportError(VIR_ERR_XML_ERROR,
                            _("iommu model '%s' can't have address"),
@@ -2643,6 +2655,18 @@ virDomainIOMMUDefValidate(const virDomainIOMMUDef *iommu)
         break;
 
     case VIR_DOMAIN_IOMMU_MODEL_VIRTIO:
+        if (iommu->intremap != VIR_TRISTATE_SWITCH_ABSENT ||
+            iommu->caching_mode != VIR_TRISTATE_SWITCH_ABSENT ||
+            iommu->eim != VIR_TRISTATE_SWITCH_ABSENT ||
+            iommu->iotlb != VIR_TRISTATE_SWITCH_ABSENT ||
+            iommu->aw_bits != 0) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("iommu model '%s' doesn't support additional attributes"),
+                           virDomainIOMMUModelTypeToString(iommu->model));
+            return -1;
+        }
+        break;
+
     case VIR_DOMAIN_IOMMU_MODEL_LAST:
         break;
     }