NAME

       rxe - Software RDMA over Ethernet

SYNOPSIS

       modprobe rdma_rxe
       This is usually performed by a configuration utility (see rdma link(8).)

DESCRIPTION

       The  rdma_rxe kernel module provides a software implementation of the RoCEv2 protocol. The
       RoCEv2 protocol is an RDMA transport protocol that exists on top of UDP/IPv4 or  UDP/IPv6.
       The InfiniBand (IB) Base Transport Header (BTH) is encapsulated in the UDP packet.

       Once  a  RXE instance has been created, communicating via RXE is the same as communicating
       via any OFED compatible Infiniband HCA, albeit in some cases with addressing implications.

       In particular, while the use of a  GRH  header  is  optional  within  IB  subnets,  it  is
       mandatory with RoCE.  Verbs applications written over IB verbs should work seamlessly, but
       they require provisioning of GRH information when creating address  vectors.  The  library
       and  driver  are modified to provide for mapping from GID to MAC addresses required by the
       hardware.

FILES

       /sys/class/infiniband/rxe[0,1,...]
              Directory that holds RDMA device information. The format is the same as other  RDMA
              devices.

       /sys/module/rdma_rxe_net/parameters/mtu
              Write only file used to configure RoCE and Ethernet MTU values.

       /sys/module/rdma_rxe/parameters/max_ucontext
              Read/Write file that sets a limit on the number of UCs allowed per RXE device.

       /sys/module/rdma_rxe/parameters/max_qp
              Read/Write file that sets a limit on the number of QPs allowed per RXE device.

       /sys/module/rdma_rxe/parameters/max_qp_wr
              Read/Write  file  that  sets  a  limit  on the number of WRs per QP allowed per RXE
              device.

       /sys/module/rdma_rxe/parameters/max_mr
              Read/Write file that sets a limit on the number of MRs allowed per RXE device.

       /sys/module/rdma_rxe/parameters/max_fmr
              Read/Write file that sets a limit on the number of FMRs allowed per RXE device.

       /sys/module/rdma_rxe/parameters/max_cq
              Read/Write file that sets a limit on the number of CQs allowed per RXE device.

       /sys/module/rdma_rxe/parameters/max_log_cqe
              Read/Write file that sets a limit on the log base 2 of the number of  CQEs  per  CQ
              allowed per RXE device.

       /sys/module/rdma_rxe/parameters/max_inline_data
              Read/Write  file  that  sets  a  limit  on the maximum amount of inline data per WR
              allowed per RXE device.

              The above configuration parameters only affect  a  new  RXE  instance  when  it  is
              created not afterwards.

       /sys/module/rdma_rxe/parameters/crc_disable
              Read/Write  file  that controls the disabling of ICRC computation. Set to a nonzero
              value for TRUE. Zero for FALSE.

       /sys/module/rdma_rxe/parameters/fast_comp|req|resp|arb
              Read/Write file that enables calling  kernel  tasklets  as  subroutines  to  reduce
              latency.

       /sys/module/rdma_rxe/parameters/nsec_per_packet|kbyte
              Read/Write  file  that  controls  static  rate pacing for output packets. If set to
              nonzero values the minimum delay to the next packet  is  set  to  nsec_per_kbyte  *
              sizeof(current packet in KBytes) or nsec_per_packet which ever is less.

       /sys/module/rdma_rxe/parameters/max_packet_per_ack
              Read/Write  file  that  controls the issuing of acks by the responder during a long
              message. If set additional acks will be generated every max_pkt_per_ack packets.

       /sys/module/rdma_rxe/parameters/max_skb_per_qp
              Read/Write file that controls the number of skbs (packets)  that  a  requester  can
              queue for sending internally.

       /sys/module/rdma_rxe/parameters/max_req_comp_gap
              Read/Write  file  that  controls the maximum gap between the PSN of request packets
              send and ack packets received.

       /sys/module/rdma_rxe/parameters/default_mtu
              Read/Write file that controls the default mtu used for UD packets.

SEE ALSO

       rdma(8), verbs(7),

AUTHORS

       Written by John Groves, Frank Zago and Bob Pearson at System Fabric Works.