[openib-general] [RFC] send side QP redirection

[Sean Hefty]

I'd like to get feedback about a possible implementation for requester QP 
redirection based on the APIs given below.  Specifically, I'm referring to GSI 
redirection (spec 13.5.2) and port and CM redirection (REJ code 24).

The basic proposal is to combine QP redirection as an extension to an address 
handle cache.  Remote agents are identified by management class, LID, and GID.

struct ib_mad_av {
	struct ib_ah *ah;
	u32 remote_qpn;
	u32 remote_qkey;
	u16 pkey_index;
};

/*
  * Insert a new destination into the map and create a new address
  * vector to it.  If the destination already exists, simply return
  * the current address vector.
  * /
struct ib_mad_av* ib_insert_mad_dest(struct ib_mad_agent*,
				     struct ib_ah_attr*,
				     mgmt_class, lid, gid, pkey);

struct ib_mad_av* ib_get_mad_av(struct ib_mad_agent*,
				mgmt_class, lid, gid);

/*
  * TBD: need to determine when to remove a destination.  Can remove
  * always if references go to 0.  Can add a delay before removal.  Can
  * maintain destinations that have been redirected. ?
  */
void ib_free_mad_av(struct ib_mad_av*);

ib_redirect_mads(struct ib_mad_av*, struct ib_mad_recv_wc*,
		 struct ib_class_port_info*);

/* GID redirection with unknown LID would be deferred */
int ib_get_mad_redirect_path(...);


Questions or thoughts?

- Sean