There is only LPAR mode on a z890, z990, z9 EC, z9 BC, z10 EC, z10 BC, and z196. You can divide your processor complex into PR/SM logical partitions. When you create logical partitions on your processor complex, you use the usage domain index on the Support Element Customize Image Profile page only if you have, or plan to add, PCICAs, PCIXCCs, CEX2Cs, CEX3Cs, CEX2As, or CEX3As.

The DOMAIN parameter is optional. The number that is specified for the usage domain index must correspond to the domain number you specified with the DOMAIN(n) keyword in the installation options data set – if you specified one. The DOMAIN keyword is required if more than one domain is specified as the usage domain on the PR/SM panels.

A PCICA, PCIXCC, CEX2C, CEX3C, CEX2A, or CEX3A can be configured and shared across multiple partitions.

With the z990, z890, z9 EC, z9 BC, z10 EC, z10 BC, and z196, there is support for up to 30 LPARs. On previous systems, where the maximum number of LPARs was 16, a domain was unique to an LPAR. With more than 16 LPARs to support, the domain may not be unique across LPARs but the same domain may be assigned to different LPARs if they are accessing different PCICAs, PCIXCCs, CEX2Cs, or CEX3Cs. This is illustrated by LPAR 1 and LPAR 3 in Figure 1. They are both assigned to usage domain 0 but on two different PCICAs.

Figure 1. Two Crypto PCICAs on a Processor Complex Running in LPAR Mode

The example in Figure 1 shows that LPAR 2 has assigned access to Domain 1 on both PCICA 1 and PCICA 2. If you were to add another PCICA, PCIXCC, CEX2C, or CEX3C to LPAR 2, Domain 1 on the new PCICA, PCIXCC, CEX2C, or CEX3C would also be assigned.

A PCIXCC and PCICA configuration with domain sharing is illustrated by LPAR 1 and LPAR 3 in Figure 2.

Figure 2. Multiple Crypto Coprocessors on a Complex Running in LPAR Mode

The example in Figure 2 shows that LPAR 2 has assigned access to Domain 1 on PCIXCC 1, CEX2C 1, and PCICA 1. LPAR 3 has assigned access to Domain 0 on CEX2C 1 and PCICA 1.