diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index aa3e3c2bfb..44926caa80 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -1282,6 +1282,7 @@ static arm_hypercall_t arm_hypercall_table[] = {
     HYPERCALL(multicall, 2),
     HYPERCALL(platform_op, 1),
     HYPERCALL_ARM(vcpu_op, 3),
+    HYPERCALL(vm_assist, 2),
 };
 
 #ifndef NDEBUG
diff --git a/xen/include/asm-arm/config.h b/xen/include/asm-arm/config.h
index f92c0a0548..4e7d20e086 100644
--- a/xen/include/asm-arm/config.h
+++ b/xen/include/asm-arm/config.h
@@ -199,6 +199,8 @@ extern unsigned long frametable_virt_end;
 #define watchdog_disable() ((void)0)
 #define watchdog_enable()  ((void)0)
 
+#define VM_ASSIST_VALID          (0)
+
 #endif /* __ARM_CONFIG_H__ */
 /*
  * Local variables: