Documentation/infiniband/ipoib.txt

   1 IP OVER INFINIBAND
   2
   3   The ib_ipoib driver is an implementation of the IP over InfiniBand
   4   protocol as specified by the latest Internet-Drafts issued by the
   5   IETF ipoib working group.  It is a "native" implementation in the
   6   sense of setting the interface type to ARPHRD_INFINIBAND and the
   7   hardware address length to 20 (earlier proprietary implementations
   8   masqueraded to the kernel as ethernet interfaces).
   9
  10 Partitions and P_Keys
  11
  12   When the IPoIB driver is loaded, it creates one interface for each
  13   port using the P_Key at index 0.  To create an interface with a
  14   different P_Key, write the desired P_Key into the main interface's
  15   /sys/class/net/<intf name>/create_child file.  For example:
  16
  17     echo 0x8001 > /sys/class/net/ib0/create_child
  18
  19   This will create an interface named ib0.8001 with P_Key 0x8001.  To
  20   remove a subinterface, use the "delete_child" file:
  21
  22     echo 0x8001 > /sys/class/net/ib0/delete_child
  23
  24   The P_Key for any interface is given by the "pkey" file, and the
  25   main interface for a subinterface is in "parent."
  26
  27 Debugging Information
  28
  29   By compiling the IPoIB driver with CONFIG_INFINIBAND_IPOIB_DEBUG set
  30   to 'y', tracing messages are compiled into the driver.  They are
  31   turned on by setting the module parameters debug_level and
  32   mcast_debug_level to 1.  These parameters can be controlled at
  33   runtime through files in /sys/module/ib_ipoib/.
  34
  35   CONFIG_INFINIBAND_IPOIB_DEBUG also enables the "ipoib_debugfs"
  36   virtual filesystem.  By mounting this filesystem, for example with
  37
  38     mkdir -p /ipoib_debugfs
  39     mount -t ipoib_debugfs none /ipoib_debufs
  40
  41   it is possible to get statistics about multicast groups from the
  42   files /ipoib_debugfs/ib0_mcg and so on.
  43
  44   The performance impact of this option is negligible, so it
  45   is safe to enable this option with debug_level set to 0 for normal
  46   operation.
  47
  48   CONFIG_INFINIBAND_IPOIB_DEBUG_DATA enables even more debug output in
  49   the data path when data_debug_level is set to 1.  However, even with
  50   the output disabled, enabling this configuration option will affect
  51   performance, because it adds tests to the fast path.
  52
  53 References
  54
  55   IETF IP over InfiniBand (ipoib) Working Group
  56     http://ietf.org/html.charters/ipoib-charter.html