9 files changed, 186 insertions, 63 deletions

diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index c522e9313c50..0005ec9285aa 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -581,11 +581,6 @@ int ccwgroup_driver_register(struct ccwgroup_driver *cdriver)
 }
 EXPORT_SYMBOL(ccwgroup_driver_register);
 
-static int __ccwgroup_match_all(struct device *dev, const void *data)
-{
-	return 1;
-}
-
 /**
  * ccwgroup_driver_unregister() - deregister a ccw group driver
  * @cdriver: driver to be deregistered
@@ -597,8 +592,7 @@ void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
 	struct device *dev;
 
 	/* We don't want ccwgroup devices to live longer than their driver. */
-	while ((dev = driver_find_device(&cdriver->driver, NULL, NULL,
-					 __ccwgroup_match_all))) {
+	while ((dev = driver_find_next_device(&cdriver->driver, NULL))) {
 		struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
 
 		ccwgroup_ungroup(gdev);
@@ -608,13 +602,6 @@ void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
 }
 EXPORT_SYMBOL(ccwgroup_driver_unregister);
 
-static int __ccwgroupdev_check_busid(struct device *dev, const void *id)
-{
-	const char *bus_id = id;
-
-	return (strcmp(bus_id, dev_name(dev)) == 0);
-}
-
 /**
  * get_ccwgroupdev_by_busid() - obtain device from a bus id
  * @gdrv: driver the device is owned by
@@ -631,8 +618,7 @@ struct ccwgroup_device *get_ccwgroupdev_by_busid(struct ccwgroup_driver *gdrv,
 {
 	struct device *dev;
 
-	dev = driver_find_device(&gdrv->driver, NULL, bus_id,
-				 __ccwgroupdev_check_busid);
+	dev = driver_find_device_by_name(&gdrv->driver, bus_id);
 
 	return dev ? to_ccwgroupdev(dev) : NULL;
 }
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index c421899be20f..131430bd48d9 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1695,18 +1695,6 @@ int ccw_device_force_console(struct ccw_device *cdev)
 EXPORT_SYMBOL_GPL(ccw_device_force_console);
 #endif
 
-/*
- * get ccw_device matching the busid, but only if owned by cdrv
- */
-static int
-__ccwdev_check_busid(struct device *dev, const void *id)
-{
-	const char *bus_id = id;
-
-	return (strcmp(bus_id, dev_name(dev)) == 0);
-}
-
-
 /**
  * get_ccwdev_by_busid() - obtain device from a bus id
  * @cdrv: driver the device is owned by
@@ -1723,8 +1711,7 @@ struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
 {
 	struct device *dev;
 
-	dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
-				 __ccwdev_check_busid);
+	dev = driver_find_device_by_name(&cdrv->driver, bus_id);
 
 	return dev ? to_ccwdev(dev) : NULL;
 }
diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h
index a06944399865..a58b45df95d7 100644
--- a/drivers/s390/cio/qdio.h
+++ b/drivers/s390/cio/qdio.h
@@ -206,8 +206,6 @@ struct qdio_output_q {
 	struct qdio_outbuf_state *sbal_state;
 	/* timer to check for more outbound work */
 	struct timer_list timer;
-	/* used SBALs before tasklet schedule */
-	int scan_threshold;
 };
 
 /*
@@ -295,6 +293,7 @@ struct qdio_irq {
 	struct qdio_ssqd_desc ssqd_desc;
 	void (*orig_handler) (struct ccw_device *, unsigned long, struct irb *);
 
+	unsigned int scan_threshold;	/* used SBALs before tasklet schedule */
 	int perf_stat_enabled;
 
 	struct qdr *qdr;
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 4142c85e77d8..5b63c505a2f7 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -647,8 +647,6 @@ static void qdio_kick_handler(struct qdio_q *q, unsigned int count)
 		qperf_inc(q, outbound_handler);
 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "koh: s:%02x c:%02x",
 			      start, count);
-		if (q->u.out.use_cq)
-			qdio_handle_aobs(q, start, count);
 	}
 
 	q->handler(q->irq_ptr->cdev, q->qdio_error, q->nr, start, count,
@@ -774,8 +772,11 @@ static inline int qdio_outbound_q_moved(struct qdio_q *q, unsigned int start)
 
 	count = get_outbound_buffer_frontier(q, start);
 
-	if (count)
+	if (count) {
 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out moved:%1d", q->nr);
+		if (q->u.out.use_cq)
+			qdio_handle_aobs(q, start, count);
+	}
 
 	return count;
 }
@@ -879,7 +880,7 @@ static inline void qdio_check_outbound_pci_queues(struct qdio_irq *irq)
 	struct qdio_q *out;
 	int i;
 
-	if (!pci_out_supported(irq))
+	if (!pci_out_supported(irq) || !irq->scan_threshold)
 		return;
 
 	for_each_output_queue(irq, out, i)
@@ -972,7 +973,7 @@ static void qdio_int_handler_pci(struct qdio_irq *irq_ptr)
 		}
 	}
 
-	if (!pci_out_supported(irq_ptr))
+	if (!pci_out_supported(irq_ptr) || !irq_ptr->scan_threshold)
 		return;
 
 	for_each_output_queue(irq_ptr, q, i) {
@@ -1527,6 +1528,7 @@ set:
 static int handle_outbound(struct qdio_q *q, unsigned int callflags,
 			   int bufnr, int count)
 {
+	const unsigned int scan_threshold = q->irq_ptr->scan_threshold;
 	unsigned char state = 0;
 	int used, rc = 0;
 
@@ -1565,8 +1567,12 @@ static int handle_outbound(struct qdio_q *q, unsigned int callflags,
 		rc = qdio_kick_outbound_q(q, 0);
 	}
 
+	/* Let drivers implement their own completion scanning: */
+	if (!scan_threshold)
+		return rc;
+
 	/* in case of SIGA errors we must process the error immediately */
-	if (used >= q->u.out.scan_threshold || rc)
+	if (used >= scan_threshold || rc)
 		qdio_tasklet_schedule(q);
 	else
 		/* free the SBALs in case of no further traffic */
@@ -1655,6 +1661,44 @@ rescan:
 }
 EXPORT_SYMBOL(qdio_start_irq);
 
+static int __qdio_inspect_queue(struct qdio_q *q, unsigned int *bufnr,
+				unsigned int *error)
+{
+	unsigned int start = q->first_to_check;
+	int count;
+
+	count = q->is_input_q ? qdio_inbound_q_moved(q, start) :
+				qdio_outbound_q_moved(q, start);
+	if (count == 0)
+		return 0;
+
+	*bufnr = start;
+	*error = q->qdio_error;
+
+	/* for the next time */
+	q->first_to_check = add_buf(start, count);
+	q->qdio_error = 0;
+
+	return count;
+}
+
+int qdio_inspect_queue(struct ccw_device *cdev, unsigned int nr, bool is_input,
+		       unsigned int *bufnr, unsigned int *error)
+{
+	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
+	struct qdio_q *q;
+
+	if (!irq_ptr)
+		return -ENODEV;
+	q = is_input ? irq_ptr->input_qs[nr] : irq_ptr->output_qs[nr];
+
+	if (need_siga_sync(q))
+		qdio_siga_sync_q(q);
+
+	return __qdio_inspect_queue(q, bufnr, error);
+}
+EXPORT_SYMBOL_GPL(qdio_inspect_queue);
+
 /**
  * qdio_get_next_buffers - process input buffers
  * @cdev: associated ccw_device for the qdio subchannel
@@ -1672,13 +1716,10 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr,
 {
 	struct qdio_q *q;
 	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
-	unsigned int start;
-	int count;
 
 	if (!irq_ptr)
 		return -ENODEV;
 	q = irq_ptr->input_qs[nr];
-	start = q->first_to_check;
 
 	/*
 	 * Cannot rely on automatic sync after interrupt since queues may
@@ -1689,25 +1730,11 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr,
 
 	qdio_check_outbound_pci_queues(irq_ptr);
 
-	count = qdio_inbound_q_moved(q, start);
-	if (count == 0)
-		return 0;
-
-	start = add_buf(start, count);
-	q->first_to_check = start;
-
 	/* Note: upper-layer MUST stop processing immediately here ... */
 	if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE))
 		return -EIO;
 
-	*bufnr = q->first_to_kick;
-	*error = q->qdio_error;
-
-	/* for the next time */
-	q->first_to_kick = add_buf(q->first_to_kick, count);
-	q->qdio_error = 0;
-
-	return count;
+	return __qdio_inspect_queue(q, bufnr, error);
 }
 EXPORT_SYMBOL(qdio_get_next_buffers);
 
diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c
index d4101cecdc8d..f4ca1d29d61b 100644
--- a/drivers/s390/cio/qdio_setup.c
+++ b/drivers/s390/cio/qdio_setup.c
@@ -248,7 +248,6 @@ static void setup_queues(struct qdio_irq *irq_ptr,
 		output_sbal_state_array += QDIO_MAX_BUFFERS_PER_Q;
 
 		q->is_input_q = 0;
-		q->u.out.scan_threshold = qdio_init->scan_threshold;
 		setup_storage_lists(q, irq_ptr, output_sbal_array, i);
 		output_sbal_array += QDIO_MAX_BUFFERS_PER_Q;
 
@@ -474,6 +473,7 @@ int qdio_setup_irq(struct qdio_initialize *init_data)
 	irq_ptr->nr_input_qs = init_data->no_input_qs;
 	irq_ptr->nr_output_qs = init_data->no_output_qs;
 	irq_ptr->cdev = init_data->cdev;
+	irq_ptr->scan_threshold = init_data->scan_threshold;
 	ccw_device_get_schid(irq_ptr->cdev, &irq_ptr->schid);
 	setup_queues(irq_ptr, init_data);
 
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 9208c0e56c33..e401a3d0aa57 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -27,6 +27,9 @@ struct workqueue_struct *vfio_ccw_work_q;
 static struct kmem_cache *vfio_ccw_io_region;
 static struct kmem_cache *vfio_ccw_cmd_region;
 
+debug_info_t *vfio_ccw_debug_msg_id;
+debug_info_t *vfio_ccw_debug_trace_id;
+
 /*
  * Helpers
  */
@@ -164,6 +167,9 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 	if (ret)
 		goto out_disable;
 
+	VFIO_CCW_MSG_EVENT(4, "bound to subchannel %x.%x.%04x\n",
+			   sch->schid.cssid, sch->schid.ssid,
+			   sch->schid.sch_no);
 	return 0;
 
 out_disable:
@@ -194,6 +200,9 @@ static int vfio_ccw_sch_remove(struct subchannel *sch)
 	kfree(private->cp.guest_cp);
 	kfree(private);
 
+	VFIO_CCW_MSG_EVENT(4, "unbound from subchannel %x.%x.%04x\n",
+			   sch->schid.cssid, sch->schid.ssid,
+			   sch->schid.sch_no);
 	return 0;
 }
 
@@ -263,27 +272,64 @@ static struct css_driver vfio_ccw_sch_driver = {
 	.sch_event = vfio_ccw_sch_event,
 };
 
+static int __init vfio_ccw_debug_init(void)
+{
+	vfio_ccw_debug_msg_id = debug_register("vfio_ccw_msg", 16, 1,
+					       11 * sizeof(long));
+	if (!vfio_ccw_debug_msg_id)
+		goto out_unregister;
+	debug_register_view(vfio_ccw_debug_msg_id, &debug_sprintf_view);
+	debug_set_level(vfio_ccw_debug_msg_id, 2);
+	vfio_ccw_debug_trace_id = debug_register("vfio_ccw_trace", 16, 1, 16);
+	if (!vfio_ccw_debug_trace_id)
+		goto out_unregister;
+	debug_register_view(vfio_ccw_debug_trace_id, &debug_hex_ascii_view);
+	debug_set_level(vfio_ccw_debug_trace_id, 2);
+	return 0;
+
+out_unregister:
+	debug_unregister(vfio_ccw_debug_msg_id);
+	debug_unregister(vfio_ccw_debug_trace_id);
+	return -1;
+}
+
+static void vfio_ccw_debug_exit(void)
+{
+	debug_unregister(vfio_ccw_debug_msg_id);
+	debug_unregister(vfio_ccw_debug_trace_id);
+}
+
 static int __init vfio_ccw_sch_init(void)
 {
-	int ret = -ENOMEM;
+	int ret;
+
+	ret = vfio_ccw_debug_init();
+	if (ret)
+		return ret;
 
 	vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw");
-	if (!vfio_ccw_work_q)
-		return -ENOMEM;
+	if (!vfio_ccw_work_q) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
 
 	vfio_ccw_io_region = kmem_cache_create_usercopy("vfio_ccw_io_region",
 					sizeof(struct ccw_io_region), 0,
 					SLAB_ACCOUNT, 0,
 					sizeof(struct ccw_io_region), NULL);
-	if (!vfio_ccw_io_region)
+	if (!vfio_ccw_io_region) {
+		ret = -ENOMEM;
 		goto out_err;
+	}
 
 	vfio_ccw_cmd_region = kmem_cache_create_usercopy("vfio_ccw_cmd_region",
 					sizeof(struct ccw_cmd_region), 0,
 					SLAB_ACCOUNT, 0,
 					sizeof(struct ccw_cmd_region), NULL);
-	if (!vfio_ccw_cmd_region)
+	if (!vfio_ccw_cmd_region) {
+		ret = -ENOMEM;
 		goto out_err;
+	}
 
 	isc_register(VFIO_CCW_ISC);
 	ret = css_driver_register(&vfio_ccw_sch_driver);
@@ -298,6 +344,7 @@ out_err:
 	kmem_cache_destroy(vfio_ccw_cmd_region);
 	kmem_cache_destroy(vfio_ccw_io_region);
 	destroy_workqueue(vfio_ccw_work_q);
+	vfio_ccw_debug_exit();
 	return ret;
 }
 
@@ -308,6 +355,7 @@ static void __exit vfio_ccw_sch_exit(void)
 	kmem_cache_destroy(vfio_ccw_io_region);
 	kmem_cache_destroy(vfio_ccw_cmd_region);
 	destroy_workqueue(vfio_ccw_work_q);
+	vfio_ccw_debug_exit();
 }
 module_init(vfio_ccw_sch_init);
 module_exit(vfio_ccw_sch_exit);
diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index 49d9d3da0282..4a1e727c62d9 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -37,9 +37,14 @@ static int fsm_io_helper(struct vfio_ccw_private *private)
 		goto out;
 	}
 
+	VFIO_CCW_TRACE_EVENT(5, "stIO");
+	VFIO_CCW_TRACE_EVENT(5, dev_name(&sch->dev));
+
 	/* Issue "Start Subchannel" */
 	ccode = ssch(sch->schid, orb);
 
+	VFIO_CCW_HEX_EVENT(5, &ccode, sizeof(ccode));
+
 	switch (ccode) {
 	case 0:
 		/*
@@ -86,9 +91,14 @@ static int fsm_do_halt(struct vfio_ccw_private *private)
 
 	spin_lock_irqsave(sch->lock, flags);
 
+	VFIO_CCW_TRACE_EVENT(2, "haltIO");
+	VFIO_CCW_TRACE_EVENT(2, dev_name(&sch->dev));
+
 	/* Issue "Halt Subchannel" */
 	ccode = hsch(sch->schid);
 
+	VFIO_CCW_HEX_EVENT(2, &ccode, sizeof(ccode));
+
 	switch (ccode) {
 	case 0:
 		/*
@@ -122,9 +132,14 @@ static int fsm_do_clear(struct vfio_ccw_private *private)
 
 	spin_lock_irqsave(sch->lock, flags);
 
+	VFIO_CCW_TRACE_EVENT(2, "clearIO");
+	VFIO_CCW_TRACE_EVENT(2, dev_name(&sch->dev));
+
 	/* Issue "Clear Subchannel" */
 	ccode = csch(sch->schid);
 
+	VFIO_CCW_HEX_EVENT(2, &ccode, sizeof(ccode));
+
 	switch (ccode) {
 	case 0:
 		/*
@@ -149,6 +164,9 @@ static void fsm_notoper(struct vfio_ccw_private *private,
 {
 	struct subchannel *sch = private->sch;
 
+	VFIO_CCW_TRACE_EVENT(2, "notoper");
+	VFIO_CCW_TRACE_EVENT(2, dev_name(&sch->dev));
+
 	/*
 	 * TODO:
 	 * Probably we should send the machine check to the guest.
@@ -229,6 +247,7 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 	struct ccw_io_region *io_region = private->io_region;
 	struct mdev_device *mdev = private->mdev;
 	char *errstr = "request";
+	struct subchannel_id schid = get_schid(private);
 
 	private->state = VFIO_CCW_STATE_CP_PROCESSING;
 	memcpy(scsw, io_region->scsw_area, sizeof(*scsw));
@@ -239,18 +258,32 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 		/* Don't try to build a cp if transport mode is specified. */
 		if (orb->tm.b) {
 			io_region->ret_code = -EOPNOTSUPP;
+			VFIO_CCW_MSG_EVENT(2,
+					   "%pUl (%x.%x.%04x): transport mode\n",
+					   mdev_uuid(mdev), schid.cssid,
+					   schid.ssid, schid.sch_no);
 			errstr = "transport mode";
 			goto err_out;
 		}
 		io_region->ret_code = cp_init(&private->cp, mdev_dev(mdev),
 					      orb);
 		if (io_region->ret_code) {
+			VFIO_CCW_MSG_EVENT(2,
+					   "%pUl (%x.%x.%04x): cp_init=%d\n",
+					   mdev_uuid(mdev), schid.cssid,
+					   schid.ssid, schid.sch_no,
+					   io_region->ret_code);
 			errstr = "cp init";
 			goto err_out;
 		}
 
 		io_region->ret_code = cp_prefetch(&private->cp);
 		if (io_region->ret_code) {
+			VFIO_CCW_MSG_EVENT(2,
+					   "%pUl (%x.%x.%04x): cp_prefetch=%d\n",
+					   mdev_uuid(mdev), schid.cssid,
+					   schid.ssid, schid.sch_no,
+					   io_region->ret_code);
 			errstr = "cp prefetch";
 			cp_free(&private->cp);
 			goto err_out;
@@ -259,23 +292,36 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 		/* Start channel program and wait for I/O interrupt. */
 		io_region->ret_code = fsm_io_helper(private);
 		if (io_region->ret_code) {
+			VFIO_CCW_MSG_EVENT(2,
+					   "%pUl (%x.%x.%04x): fsm_io_helper=%d\n",
+					   mdev_uuid(mdev), schid.cssid,
+					   schid.ssid, schid.sch_no,
+					   io_region->ret_code);
 			errstr = "cp fsm_io_helper";
 			cp_free(&private->cp);
 			goto err_out;
 		}
 		return;
 	} else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) {
+		VFIO_CCW_MSG_EVENT(2,
+				   "%pUl (%x.%x.%04x): halt on io_region\n",
+				   mdev_uuid(mdev), schid.cssid,
+				   schid.ssid, schid.sch_no);
 		/* halt is handled via the async cmd region */
 		io_region->ret_code = -EOPNOTSUPP;
 		goto err_out;
 	} else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) {
+		VFIO_CCW_MSG_EVENT(2,
+				   "%pUl (%x.%x.%04x): clear on io_region\n",
+				   mdev_uuid(mdev), schid.cssid,
+				   schid.ssid, schid.sch_no);
 		/* clear is handled via the async cmd region */
 		io_region->ret_code = -EOPNOTSUPP;
 		goto err_out;
 	}
 
 err_out:
-	trace_vfio_ccw_io_fctl(scsw->cmd.fctl, get_schid(private),
+	trace_vfio_ccw_io_fctl(scsw->cmd.fctl, schid,
 			       io_region->ret_code, errstr);
 }
 
@@ -308,6 +354,9 @@ static void fsm_irq(struct vfio_ccw_private *private,
 {
 	struct irb *irb = this_cpu_ptr(&cio_irb);
 
+	VFIO_CCW_TRACE_EVENT(6, "IRQ");
+	VFIO_CCW_TRACE_EVENT(6, dev_name(&private->sch->dev));
+
 	memcpy(&private->irb, irb, sizeof(*irb));
 
 	queue_work(vfio_ccw_work_q, &private->io_work);
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 5eb61116ca6f..f0d71ab77c50 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -124,6 +124,11 @@ static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
 	private->mdev = mdev;
 	private->state = VFIO_CCW_STATE_IDLE;
 
+	VFIO_CCW_MSG_EVENT(2, "mdev %pUl, sch %x.%x.%04x: create\n",
+			   mdev_uuid(mdev), private->sch->schid.cssid,
+			   private->sch->schid.ssid,
+			   private->sch->schid.sch_no);
+
 	return 0;
 }
 
@@ -132,6 +137,11 @@ static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
 	struct vfio_ccw_private *private =
 		dev_get_drvdata(mdev_parent_dev(mdev));
 
+	VFIO_CCW_MSG_EVENT(2, "mdev %pUl, sch %x.%x.%04x: remove\n",
+			   mdev_uuid(mdev), private->sch->schid.cssid,
+			   private->sch->schid.ssid,
+			   private->sch->schid.sch_no);
+
 	if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
 	    (private->state != VFIO_CCW_STATE_STANDBY)) {
 		if (!vfio_ccw_sch_quiesce(private->sch))
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index f1092c3dc1b1..bbe9babf767b 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -17,6 +17,7 @@
 #include <linux/eventfd.h>
 #include <linux/workqueue.h>
 #include <linux/vfio_ccw.h>
+#include <asm/debug.h>
 
 #include "css.h"
 #include "vfio_ccw_cp.h"
@@ -139,4 +140,20 @@ static inline void vfio_ccw_fsm_event(struct vfio_ccw_private *private,
 
 extern struct workqueue_struct *vfio_ccw_work_q;
 
+
+/* s390 debug feature, similar to base cio */
+extern debug_info_t *vfio_ccw_debug_msg_id;
+extern debug_info_t *vfio_ccw_debug_trace_id;
+
+#define VFIO_CCW_TRACE_EVENT(imp, txt) \
+		debug_text_event(vfio_ccw_debug_trace_id, imp, txt)
+
+#define VFIO_CCW_MSG_EVENT(imp, args...) \
+		debug_sprintf_event(vfio_ccw_debug_msg_id, imp, ##args)
+
+static inline void VFIO_CCW_HEX_EVENT(int level, void *data, int length)
+{
+	debug_event(vfio_ccw_debug_trace_id, level, data, length);
+}
+
 #endif