Index: b/hw/s390-virtio.c
===================================================================
--- a/hw/s390-virtio.c
+++ b/hw/s390-virtio.c
@@ -130,6 +130,26 @@ int s390_virtio_hypercall(CPUState *env,
     return r;
 }
 
+/*
+ * The number of running CPUs. On s390 a shutdown is the state of all CPUs
+ * being either stopped or disabled (for interrupts) waiting. We have to
+ * track this number to call the shutdown sequence accordingly. This
+ * number is modified either on startup or while holding the big qemu lock.
+ */
+static unsigned s390_running_cpus;
+
+void kvm_s390_add_running_cpu(CPUState *env)
+{
+    assert(env->halted == 0);
+    s390_running_cpus++;
+}
+
+unsigned kvm_s390_del_running_cpu(CPUState *env)
+{
+    assert(s390_running_cpus >= 1);
+    return --s390_running_cpus;
+}
+
 /* PC hardware initialisation */
 static void s390_init(ram_addr_t my_ram_size,
                       const char *boot_device,
@@ -189,6 +209,7 @@ static void s390_init(ram_addr_t my_ram_
 
     env->halted = 0;
     env->exception_index = 0;
+    kvm_s390_add_running_cpu(env);
 
     if (kernel_filename) {
         kernel_size = load_image(kernel_filename, qemu_get_ram_ptr(0));
Index: b/target-s390x/cpu.h
===================================================================
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -292,6 +292,8 @@ void kvm_s390_interrupt(CPUState *env, i
 void kvm_s390_virtio_irq(CPUState *env, int config_change, uint64_t token);
 void kvm_s390_interrupt_internal(CPUState *env, int type, uint32_t parm,
                                  uint64_t parm64, int vm);
+void kvm_s390_add_running_cpu(CPUState *env);
+unsigned kvm_s390_del_running_cpu(CPUState *env);
 #else
 static inline void kvm_s390_interrupt(CPUState *env, int type, uint32_t code)
 {
@@ -307,6 +309,16 @@ static inline void kvm_s390_interrupt_in
                                                int vm)
 {
 }
+
+static inline void kvm_s390_add_running_cpu(CPUState *env)
+{
+}
+
+static inline unsigned kvm_s390_del_running_cpu(CPUState *env)
+{
+    return 0;
+}
+
 #endif
 CPUState *s390_cpu_addr2state(uint16_t cpu_addr);
 
Index: b/target-s390x/kvm.c
===================================================================
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -185,6 +185,12 @@ void kvm_s390_interrupt_internal(CPUStat
         return;
     }
 
+    /*
+     * We can only deliver interrupts to (interrupt) enabled CPUs.
+     * We dont call kvm_s390_add_running_cpu here, since CPUs in enabled wait
+     * will wait inside the kernel (no exit). Therefore, the targeted
+     * CPUs was neither disabled waiting or stopped for qemu.
+     */
     env->halted = 0;
     env->exception_index = -1;
     qemu_cpu_kick(env);
@@ -301,6 +307,7 @@ static int s390_cpu_restart(CPUState *en
     kvm_s390_interrupt(env, KVM_S390_RESTART, 0);
     env->halted = 0;
     env->exception_index = -1;
+    kvm_s390_add_running_cpu(env);
     qemu_cpu_kick(env);
     dprintf("DONE: SIGP cpu restart: %p\n", env);
     return 0;
@@ -425,16 +432,24 @@ static int handle_intercept(CPUState *en
             r = handle_instruction(env, run);
             break;
         case ICPT_WAITPSW:
-            /* XXX What to do on system shutdown? */
+            if (kvm_s390_del_running_cpu(env) == 0) {
+                qemu_system_shutdown_request();
+            }
             env->halted = 1;
             env->exception_index = EXCP_HLT;
+            r = EXCP_HALTED;
             break;
         case ICPT_SOFT_INTERCEPT:
             fprintf(stderr, "KVM unimplemented icpt SOFT\n");
             exit(1);
             break;
         case ICPT_CPU_STOP:
-            qemu_system_shutdown_request();
+            if (kvm_s390_del_running_cpu(env) == 0) {
+                qemu_system_shutdown_request();
+            }
+            env->halted = 1;
+            env->exception_index = EXCP_HLT;
+            r = EXCP_HALTED;
             break;
         case ICPT_IO:
             fprintf(stderr, "KVM unimplemented icpt IO\n");
@@ -468,8 +483,6 @@ int kvm_arch_handle_exit(CPUState *env, 
 
     if (ret == 0) {
         ret = EXCP_INTERRUPT;
-    } else if (ret > 0) {
-        ret = 0;
     }
     return ret;
 }