z/OS announced SMC-Dv2 support here, see section "Shared Memory Communications Version 2 (SMCv2) multiple IP subnet support".
SMC-D v2 provides support for peers in different IP subnets, and eliminates the need to configure PNET IDs, simplifying the configuration significantly. Linux on Z support is being worked on.
When SMC-Dv2 is enabled in z/OS, a compatibility patch is required in Linux on Z, which is available in the following minimum Linux distribution levels:
- RHEL 8.3, Linux kernel 4.18.0-228
- SLES 15 SP2, Linux kernel 5.3.18-24.9.1
- Ubuntu 20.04, Linux kernel 5.4.0-45.49