diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 734d302ba389996c6f29e62df89be43b8e294017..c36cd35e03f388b13d4323f445d6e3e7853f355f 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -213,8 +213,7 @@ struct kvm_s390_float_interrupt {
 	struct list_head list;
 	atomic_t active;
 	int next_rr_cpu;
-	unsigned long idle_mask[(KVM_MAX_VCPUS + sizeof(long) - 1)
-				/ sizeof(long)];
+	unsigned long idle_mask[BITS_TO_LONGS(KVM_MAX_VCPUS)];
 	unsigned int irq_count;
 };