[ofa-general] [PATCHv5 0/10] RDMAoE support

[Eli Cohen]

RDMA over Ethernet (RDMAoE) allows running the IB transport protocol using
Ethernet frames, enabling the deployment of IB semantics on lossless Ethernet
fabrics. RDMAoE packets are standard Ethernet frames with an IEEE assigned
Ethertype, a GRH, unmodified IB transport headers and payload.  IB subnet
management and SA services are not required for RDMAoE operation; Ethernet
management practices are used instead. RDMAoE encodes IP addresses into its
GIDs and resolves MAC addresses using the host IP stack. For multicast GIDs,
standard IP to MAC mappings apply.

To support RDMAoE, a new transport protocol was added to the IB core. An RDMA
device can have ports with different transports, which are identified by a port
transport attribute.  The RDMA Verbs API is syntactically unmodified. When
referring to RDMAoE ports, Address handles are required to contain GIDs while
LID fields are ignored. The Ethernet L2 information is subsequently obtained by
the vendor-specific driver (both in kernel- and user-space) while modifying QPs
to RTR and creating address handles.  As there is no SA in RDMAoE, the CMA code
is modified to fill the necessary path record attributes locally before sending
CM packets. Similarly, the CMA provides to the user the required address handle
attributes when processing SIDR requests and joining multicast groups.

In this patch set, an RDMAoE port is currently assigned a single GID, encoding
the IPv6 link-local address of the corresponding netdev; the CMA RDMAoE code
temporarily uses IPv6 link-local addresses as GIDs instead of the IP address
provided by the user, thereby supporting any IP address.

To enable RDMAoE with the mlx4 driver stack, both the mlx4_en and mlx4_ib
drivers must be loaded, and the netdevice for the corresponding RDMAoE port
must be running. Individual ports of a multi port HCA can be independently
configured as Ethernet (with support for RDMAoE) or IB, as is already the case.
We have successfully tested MPI, SDP, RDS, and native Verbs applications over
RDMAoE.

Following is a series of 10 patches based on version 2.6.30 of the Linux
kernel. This new series reflects changes based on feedback from the community
on the previous set of patches, and is tagged v5.

Changes from v4:
1. Added rdma_is_transport_supported() and used it to simplify conditionals
throughout the code.
2. ib_register_mad_agent()for QP0 is only called for IB ports 3. PATCH 5/10
changed from "Enable support for RDMAoE ports" to "Enable support only for IB
ports".
4. MAD services from userspace currently not supported for RDMAoE ports.
5. Add kref to struct cma_multicast to aid in maintaining reference count on
the object. This is to avoid freeing the object while the worker thread is
still using it.
6. Return immediate error for invalid MTU when resolving an RDMAoE path 7.
Don't fail resolve path if rate is 0 since this value stands for
IB_RATE_PORT_CURRENT.
8. In cma_rdmaoe_join_multicast(), fail immediately if mtu is zero.
9. Add ucma_copy_rdmaoe_route()instead of modifying ucma_copy_ib_route().
10. Bug fix: in PATCH 10/10, call flush_workqueue after unregistering netdev
notifiers
11. Multicast no longer use the broadcast MAC.
12. No changes to patches 2, 7 and 8 from the v4 series.

Signed-off-by: Eli Cohen <eli at mellanox.co.il>
---

 b/drivers/infiniband/core/agent.c           |   38 ++-
 b/drivers/infiniband/core/cm.c              |   25 +-
 b/drivers/infiniband/core/cma.c             |   54 ++--
 b/drivers/infiniband/core/mad.c             |   41 ++-
 b/drivers/infiniband/core/multicast.c       |    4 
 b/drivers/infiniband/core/sa_query.c        |   39 ++-
 b/drivers/infiniband/core/ucm.c             |    8 
 b/drivers/infiniband/core/ucma.c            |    2 
 b/drivers/infiniband/core/ud_header.c       |  111 ++++++++++
 b/drivers/infiniband/core/user_mad.c        |    6 
 b/drivers/infiniband/core/uverbs.h          |    1 
 b/drivers/infiniband/core/uverbs_cmd.c      |   32 ++
 b/drivers/infiniband/core/uverbs_main.c     |    1 
 b/drivers/infiniband/core/verbs.c           |   25 ++
 b/drivers/infiniband/hw/mlx4/ah.c           |  187 +++++++++++++---
 b/drivers/infiniband/hw/mlx4/mad.c          |   32 +-
 b/drivers/infiniband/hw/mlx4/main.c         |  309 +++++++++++++++++++++++++---
 b/drivers/infiniband/hw/mlx4/mlx4_ib.h      |   19 +
 b/drivers/infiniband/hw/mlx4/qp.c           |  172 ++++++++++-----
 b/drivers/infiniband/ulp/ipoib/ipoib_main.c |   12 -
 b/drivers/net/mlx4/en_main.c                |   15 +
 b/drivers/net/mlx4/en_port.c                |    4 
 b/drivers/net/mlx4/en_port.h                |    3 
 b/drivers/net/mlx4/fw.c                     |    3 
 b/drivers/net/mlx4/intf.c                   |   20 +
 b/drivers/net/mlx4/main.c                   |    6 
 b/drivers/net/mlx4/mlx4.h                   |    1 
 b/include/linux/mlx4/cmd.h                  |    1 
 b/include/linux/mlx4/device.h               |   31 ++
 b/include/linux/mlx4/driver.h               |   16 +
 b/include/linux/mlx4/qp.h                   |    8 
 b/include/rdma/ib_addr.h                    |   92 ++++++++
 b/include/rdma/ib_pack.h                    |   26 ++
 b/include/rdma/ib_user_verbs.h              |   21 +
 b/include/rdma/ib_verbs.h                   |   11 
 b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c   |    3 
 b/net/sunrpc/xprtrdma/svc_rdma_transport.c  |    2 
 drivers/infiniband/core/cm.c                |    5 
 drivers/infiniband/core/cma.c               |  207 ++++++++++++++++++
 drivers/infiniband/core/mad.c               |   37 ++-
 drivers/infiniband/core/ucm.c               |   12 -
 drivers/infiniband/core/ucma.c              |   31 ++
 drivers/infiniband/core/user_mad.c          |   15 -
 drivers/infiniband/core/verbs.c             |   10 
 include/rdma/ib_verbs.h                     |   15 +
 45 files changed, 1440 insertions(+), 273 deletions(-)