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Configuring Shared Memory Communications Version - Direct Memory Access version 2 (SMC-Dv2) For Your z/OS Environment

How To


Summary

This document provides an overview on how to properly implement SMC-Dv2 on a z/OS environment.

Objective

This document includes:
  • SMC-Dv2 requirements
  • TCP/IP profile configuration

Environment

Hardware Requirements
  • IBM z15 or z16
  • ISMv2 devices
    • Virtual PCI network adapter of VCHID type ISM 
Software Requirements
  • Software: z/OS 
    • IBM z/OS V2R4 (via APAR) or later
    • Define at least one user-defined Enterprise ID in z/OS! (disabled by default)
  • Environments: LPAR or z/VM guests
A diagram showing two LPARS with a TCP data connection between ISM devices on each partner

Steps

Setting up the environment for Shared Memory Communications - Direct Memory Access
Define ISM VCHIDs:
  • (Recommended) Without a PNetID in the HCD
  • With a PNetID in the hardware configuration definition (HCD) that matches the PNetID definitions for any OSA or HiperSockets devices that use the ISM device for SMC-D (SMC-Dv1 compatibility) 
Hardware Configuration Definition
On the HCD main panel, do the following:
  1. On the Primary Task Selection page window, select “Define configuration data”.
    • The z/OS TN3270 window showing the Hardware Configuration Primary Task Selection panel

  2. On the resulting panel, select “Processors”. 

    • "define modify or view configuration data" panel of HCD

  3. On the Processor List panel, select an eligible processor and action “Work with PCIe functions”.

    • Processor List of HCD

  4. Use PF20=Right to scroll to the partition assignments for the displayed PCIe functions, one panel for each defined channel subsystem

    • PCIe function list of HCD

  5. Use F11=Add to define a new PCIe function

    • HCD panel showing PCIe function list

  6. Set PCIe Adapter Type to ISM

    • Add adapter type window listing options which includes ISM and RoCE-2

  7. Add a virtual channel ID

    • HCD panel showing Add PCIe function window

  8. Use F11=Add to define a new PCIe function
  •  PCIe function list in HCD showing newly added ISM device

Sample RoCE IOCP / IOCDS declaration

​​​​Sample RoCE IOCP / IOCDS declaration for SMC-D ISM device

z/OS TCP/IP profile configuration requirements

  1. Configure GLOBALCONFIG SMCD statement
  2. Add SYSTEMEID or User-defined EID on SMCGLOBAL statement
    • SystemEID is specified on GLOBALCONFIG SMCD statement
    • User-defined EIDs are specified on SMCGLOBAL
  3. Define SMCD and IP address (IPADDR) with a subnet mask
    • Using HiperSockets: configured on IPAQIDIO INTERFACE STATEMENT
    • Using OSA: configured on IPAQENET INTERFACE statement. Also, include CHPIDTYPE OSD

Start the OSA and HiperSocket interfaces (ISM interfaces are automatically started).

Here are the format of the definitions needed for the TCP/IP profile:

; ----------------------------------------------------------------------

; GLOBALCONFIG statements to enable SMC-Dv2

; ----------------------------------------------------------------------

; A user-defined EID 

GLOBALCONFIG SMCD  

  SMCGLOBAL SMCEID user_EID_values ENDSMCEID

; A system-defined EID

GLOBALCONFIG SMCD SYSTEMEID

; ----------------------------------------------------------------------

; INTERFACE statements for IPv4

; ----------------------------------------------------------------------

; For HiperSockets

INTERFACE intf_name 

  DEFINE IPAQIDIO

  SMCD 

  IPADDR ipv4addr/num_mask_bits

; For OSA-Express QDIO ethernet

INTERFACE intf_name 

  DEFINE IPAQENET

  SMCD 

  CHPIDTYPE OSD

  IPADDR ipv4addr/num_mask_bits

Additional Information

Verification

Netstat Devlinks/-d for OSD report

  • SMC V1 and V2 capabilities
  • If V2 capable, displays configured PFID, SMCRIPADDR, and SMCRMTU

Format:

DTCPIP,procname,NETSTAT,DEVlinks

Example:

D TCPIP,TCPIPB,NETSTAT,DEVLINKS

…

IntfName: GIG3 IntfType: IPAQENET IntfStatus: Ready

  PortName: GIG2E Datapath: OBE2 DatapathStatus: Ready

  CHPIDType: OSD   SMCR: Yes

  PNetID: IBMTRUNKSET1   SMCD: Yes

...

SMCR Capability: V2

  Associated Multi-subnet RNIC interface: EZARIUT10011

  RoCE PFID: 0011 SMCRMTU: 1024

  SMCRIPADDR: 9.82.24.157

  Unassociated ISM interfaces: EZAISMU1

IntfName: EZARIUT10011  IntfType: RNIC  IntfStatus: READY

Netstat CONFIG/-f report

Displays:
  • User-defined EIDs
  • SMC exclude and permit lists

Format:

DTCPIP,procname,NETSTAT,CONFIG

Example:

D TCPIP,TCPIPB,NETSTAT,CONFIG

…

Global Configuration Information:

SMCGlobal:

AutoCache: YES AutoSMC: YES

SMCEID: IBM-COMMSERVER-MULTIPASS

SMC Exclude List: NONE

SMC Permit List: ALL

SMCR: YES

FixedMemory: 0000256M TcpKeepMinInt: 00000300

SMCD: YES

FixedMemory: 0000256M TcpKeepMinInt: 00000300

SMCDSYSEID: YES (IBM-SYSZ-ISMSEID0000000023B83931)

Netstat ALL/-a report

  • Displays SMC version and EID
Example:

D TCPIP,TCPIPD,N,ALL,IPPORT=9.82.24.151+21 

EZD0101I NETSTAT CS V2R4 TCPIPD 331                      

CLIENT NAME: FTPSERVE                 CLIENT ID: 00000CC2 

  LOCAL SOCKET: ::FFFF:9.82.24.153..21                    

  FOREIGN SOCKET: ::FFFF:9.82.24.151..1242 

…

 SMC INFORMATION:                                                

       SMCDSTATUS:       ACTIVE           SMCDVERSION:        2      

         LOCALSMCLINKID: 02010001         REMOTESMCLINKID:    01010001

         LOCALSMCRCVBUF: 64K              REMOTESMCRCVBUF:    64K    

         SMCEID:         IBM-SYSZ-ISMSEID0000000023B83931             

For more information, see resources below.

Document Location

Worldwide

Operating System

z/OS:All operating systems listed

[{"Type":"MASTER","Line of Business":{"code":"LOB56","label":"Z HW"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG90","label":"z\/OS"},"ARM Category":[{"code":"a8m0z0000000AfbAAE","label":"z\/OS Comm Server-\u003ETCPIP-\u003EIF\/DLC - Data Link Control-\u003ESMC-D - Shared Memory Communications Direct"}],"ARM Case Number":"","Platform":[{"code":"PF035","label":"z\/OS"}],"Version":"2.5.0;and future releases"}]

Product Synonym

Z; Z systems; z/OS; Communications Server

Document Information

Modified date:
02 May 2023

UID

ibm16985319

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