Displaying PCIe information
For each online PCIe device, there is a number of read-only attributes in sysfs that provide information about the device.
About this task
The sysfs representation of a PCIe device or slot is a directory of the form /sys/bus/pci/devices/<function_address>, where <function_address> identifies the PCIe device. This sysfs directory contains a number of attributes with information about the PCIe device.
| Attribute | Explanation |
|---|---|
| function_handle | Eight-character, hexadecimal PCI-function (device) handle. |
| function_id | Eight-character, hexadecimal PCI-function (device) ID. The ID identifies the PCIe device within the processor configuration. This value specifies the slot at /sys/bus/pci/slots. |
| pchid | Four-character, hexadecimal, physical channel ID. Specifies the slot of the PCIe adapter in the I/O drawer. Thus identifies the adapter that provides the device. |
| pfgid | Two-character, hexadecimal, physical function group ID. |
pfip/segment0
/segment1 /segment2 /segment3 |
Two-character, hexadecimal, PCI-function internal path. Provides an abstract indication of the path that is used to access the PCI function. This can be used to compare the paths used by two or more PCI functions, to give an indication of the degree of isolation between them. |
| uid | Up to eight-character, hexadecimal, user-defined identifier. |
| vfn | Four-character, hexadecimal, number that identifies the virtual function within the adapter. |
| util_string | Type-specific information about the device. For RoCE devices and ISM devices, it contains the PNET ID if a PNET ID has been assigned in the I/O configuration. |
Procedure
Issue a command of this form to read an attribute:
# cat /sys/bus/pci/devices/<function_address>/<attribute>