[PATCH rdma-next 0/4] Support multiple path records

[Leon Romanovsky <leon@kernel.org>]

From: Leon Romanovsky <leonro@nvidia.com>

From Mark:

These patches allow IB core to receive multiple path records from
user-space rdma netlink service.

Currently only one GMP PR is supported when doing a PR query. This means
in a fabric with multiple subnets, when a packet goes out of the sender,
it’s assigned with a LID to a router as its destination LID. The current
solution selects a specific router per destination, means that there is
no advanced routing from the sender towards the network.

This patchset supports to receive an inbound PR and an outbound PR along
with the GMP PR. The LIDs in these 3 PRs can be used in this way:
1. GMP PR: used as the standard local/remote LIDs;
2. DLID of outbound PR: Used as the "dlid" field for outbound traffic;
3. DLID of inbound PR: Used as the "dlid" field for outbound traffic in
   responder side.

The inboundPR.dlid is passed to responder with the "primary_LID" filed
in the ConnectRequest message.

With this, the user-space rdma netlink service can set special DLIDs
in inbound/outbound PRs, to select specific routers for datapath
between the 2 nodes.

The following cases were tested:
- New kernel with new netlink service that supports multiple path
  records;
- New kernel with old netlink service;
- Old kernel with new netlink service;
- Client side new kernel with new netlink service, server side with
  old kernel.

Thanks.

Mark Zhang (4):
  RDMA/core: Rename rdma_route.num_paths field to num_pri_alt_paths
  RDMA/cma: Multiple path records support with netlink channel
  RDMA/cm: Use SLID in the work completion as the DLID in responder side
  RDMA/cm: Use DLID from inbound/outbound PathRecords as the datapath
    DLID

 drivers/infiniband/core/cm.c              |  39 +++-
 drivers/infiniband/core/cma.c             |  88 ++++++--
 drivers/infiniband/core/sa_query.c        | 235 +++++++++++++++-------
 drivers/infiniband/core/ucma.c            |  10 +-
 drivers/infiniband/ulp/ipoib/ipoib_main.c |   2 +-
 drivers/infiniband/ulp/srp/ib_srp.c       |   2 +-
 include/rdma/ib_cm.h                      |   2 +
 include/rdma/ib_sa.h                      |   3 +-
 include/rdma/rdma_cm.h                    |  13 +-
 9 files changed, 284 insertions(+), 110 deletions(-)

-- 
2.37.2