Displaying information about the AP bus

Use the lszcrypt -b command to display status information about the AP bus; alternatively, you can use sysfs.

About this task

The AP bus is represented in sysfs as a directory of the form

/sys/bus/ap

The sysfs directory contains a number of attributes with information about the AP bus.

Table 1. AP bus attributes
Attribute	Explanation
ap_domain	Read-only attribute that represents the domain. By default the kernel selects a domain. Alternatively, you can use the `domain=` module parameter
ap_max_domain_id	Read-only attribute that represents the largest possible domain ID. Domain IDs can range from 0 to this number, which depends on the mainframe model.
ap_control_domain_mask	Read-only attribute that represents the installed control domain facilities as a 32-byte field in hexadecimal notation. A maximum number of 256 domains can be addressed. Each bit position represents a dedicated control domain.
ap_usage_domain_mask	Read-only attribute that represents the installed usage domain facilities as a 32-byte field in hexadecimal notation. A maximum number of 256 domains can be addressed. Each bit position represents a usage domain.
ap_interrupts	Read-only attribute that indicates whether interrupt handling for the AP bus is enabled.
config_time	Read-write attribute that represents a time interval in seconds used to detect new crypto devices.
poll_thread	Read-write attribute that indicates whether polling for the AP bus is enabled.
poll_timeout	Read-write attribute that represents the time interval of the poll thread in nanoseconds.

# lszcrypt -b
ap_domain=5
ap_interrupts are enabled
config_time=30 (seconds)
poll_thread is disabled
poll_timeout=250000 (nanoseconds)