CCW hotplug events

Red Hat Enterprise Linux 8.6 LPAR mode z/VM guest KVM guest

A hotplug event is generated when a CCW device appears or disappears with a machine check.

The hotplug events provide the following variables:
CU_TYPE
for the control unit type of the device that appeared or disappeared.
CU_MODEL
for the control unit model of the device that appeared or disappeared.
DEV_TYPE
for the type of the device that appeared or disappeared.
DEV_MODEL
for the model of the device that appeared or disappeared.
MODALIAS
for the module alias of the device that appeared or disappeared. The module alias is the same value that is contained in /sys/devices/css0/<subchannel_id>/<device_bus_id>/modalias and is of the formatccw:t<cu_type>m<cu_model> or ccw:t<cu_type>m<cu_model>dt<dev_type>dm<dev_model>
Hotplug events can be used, for example, for:
  • Automatically setting devices online as they appear
  • Automatically loading driver modules for which devices have appeared