diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index 4a340cb..72a130b 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -76,7 +76,9 @@
 	gfn     = slot->base_gfn;
 	end_gfn = gfn + slot->npages;
 
-	flags = IOMMU_READ | IOMMU_WRITE;
+	flags = IOMMU_READ;
+	if (!(slot->flags & KVM_MEM_READONLY))
+		flags |= IOMMU_WRITE;
 	if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY)
 		flags |= IOMMU_CACHE;