static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
{
	struct hv_message *msg = &stimer->msg;
	struct hv_timer_message_payload *payload =
			(struct hv_timer_message_payload *)&msg->u.payload;

	memset(&msg->header, 0, sizeof(msg->header));
	msg->header.message_type = HVMSG_TIMER_EXPIRED;
	msg->header.payload_size = sizeof(*payload);

	payload->timer_index = stimer->index;
	payload->expiration_time = 0;
	payload->delivery_time = 0;
}