## C.3.1 FUNCTION identifier 

The FUNCTION identifier (FID) is a hexadecimal number 000 - FFF that you use to assign a PCHID to the FUNCTION to identify the specific hardware feature in the PCIe I/O drawer. 

Because the FUNCTION is not related to a channel subsystem, all LPARs on a central processor complex (CPC) can be defined to it. However, a FUNCTION cannot be shared between LPARs. It is only dedicated or reconfigurable by using the PART  parameter. The TYPE parameter is required for z14. 

## C.3.2 Virtual function number 

If you want several LPARs to use a zEDC Express feature, you must use a Virtual Function (VF) number. A VF number is a number 1 - nnn , where nnn  is the maximum number of LPARs that the feature supports. The maximum is 15 for the zEDC Express feature, 31 for the 10GbE RoCE Express (FC 0411), 126 for the RoCE Express2 feature, and 254 for the zHyperLink Express feature$^{3}$. 

## C.3.3 Physical network identifier 

The physical network ID (PNETID) is required to set up the Shared Memory Communications over Remote Direct Memory Access (SMC-R) communication between two RoCE Express/Express2 features. Each FUNCTION definition supports up to four PNETIDs. 

Notes:  Consider the following points: 

GLYPH<SM590000> For more information about FUNCTION statement, see IBM Z Input/Output Configuration Program User’s Guide for ICP IOCP , SB10-7163. 

GLYPH<SM590000> The definition of RoCE Express/Express2 feature is required to pair up with an OSD CHPID definition by using the parameter of PNETID. The OSD CHPID definition statement is not listed in the example. 

