NAME

       rxe - Software RDMA over Ethernet

SYNOPSIS

       modprobe rdma_rxe
       This is usually performed by a configuration utility (see rxe_cfg(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/add
              Write  only  file  used  by  rxe_cfg(8) to add new RXE devices to existing Ethernet
              devices.

       /sys/module/rdma_rxe_net/parameters/remove
              Write only file used by rxe_cfg(8) to remove RXE devices.

       /sys/module/rdma_rxe_net/parameters/mtu
              Write only file used by rxe_cfg(8) 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

       rxe_cfg(8), verbs(7),

AUTHORS

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