I can. Chapter 17 verse 3.1 17.3.1 Loopback "An HCA shall be able to internally loopback a packet sent to itself. That is, the verbs layer can specify a packet to be delivered to the same port (possibly a different QP though). The packet shall be delivered without the packet appearing on the port's physical link. This loopback shall be able to function without requiring the presence of an external switch. InfiniBand does not reserve a special LID value to indicate loopback. Instead, the DLID (and DGID if present) of a loopback packet should be the LID (and GID) of the port on which the packet was emitted. For loopback packets, a channel adapter implementation may ignore other path information, such as MTU, that is not otherwise needed for the receive buffer or for the completion queue as specified in section 11.4.2.1 Poll for Completion on page 629."
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Roland Dreier Sent: Thursday, February 04, 2010 3:51 PM To: Steve Wise Cc: Sean Hefty; linux-rdma; OpenFabrics EWG; Jeff Squyres Subject: Re: bug 1918 - openmpi broken due to rdma-cm changes > Is this only an iwarp issue? IE do all IB devices support hw > loopback? And will all future devices support it (IE is it an IBTA > requirement)? I do think IBA requires loopback to work. Can't quote chapter & verse off the top of my head. -- Roland Dreier <[email protected]> Cisco.com - http://www.cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/index.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html _______________________________________________ ewg mailing list [email protected] http://lists.openfabrics.org/cgi-bin/mailman/listinfo/ewg
