Dedicated RoCE environment

A RoCE Express feature operating in a dedicated RoCE environment can only be used by a single LPAR. z/OS allows the feature to be shared by up to eight TCP/IP stacks within a single LPAR. Each TCP/IP stack uses the same PCIe function ID (PFID) value to define its representation of the RoCE Express feature. The PFID value is defined by using traditional hardware configuration definition (HCD) tools. In a dedicated RoCE environment, only one of the two available ports can be used at a time.

Figure 1 is an example of a 10GbE RoCE Express feature that is defined in a dedicated RoCE environment. A single z/OS image (z/OS 2) is using the 10GbE RoCE Express features identified by PCHID values 100 and 200. Two PFID values (0001 and 0016) are defined to represent the features, and the PFID values correspond to the FID values defined in the HCD for the features. No other z/OS images can use these two features, although up to eight stacks on z/OS 2 can use the features. In this example, port 1 is used on both features, and port 2 cannot be used when port 1 is in use.

Figure 1. 10GbE RoCE Express feature in a dedicated RoCE environment

A dedicated RoCE environment mode is supported on an IBM® zEnterprise® EC12 (zEC12) with driver 15, or an IBM zEnterprise BC12 (zBC12).