diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index 5d9bafe..03459b8 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -562,6 +562,7 @@ static int kvm_radix_test_clear_dirty(struct kvm *kvm,
 	unsigned int shift;
 	int ret = 0;
 
+	spin_lock(&kvm->mmu_lock);
 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
 	if (ptep && pte_present(*ptep) && pte_dirty(*ptep)) {
 		ret = 1;
@@ -571,6 +572,7 @@ static int kvm_radix_test_clear_dirty(struct kvm *kvm,
 					gpa, shift);
 		kvmppc_radix_tlbie_page(kvm, gpa, shift);
 	}
+	spin_unlock(&kvm->mmu_lock);
 	return ret;
 }