• Jack Morgenstein's avatar
    IB/mlx4: Fix possible vl/sl field mismatch in LRH header in QP1 packets · fd10ed8e
    Jack Morgenstein authored
    In MLX qp packets, the LRH (built by the driver) has both a VL field
    and an SL field. When building a QP1 packet, the VL field should
    reflect the SLtoVL mapping and not arbitrarily contain zero (as is
    done now). This bug causes credit problems in IB switches at
    high rates of QP1 packets.
    
    The fix is to cache the SL to VL mapping in the driver, and look up
    the VL mapped to the SL provided in the send request when sending
    QP1 packets.
    
    For FW versions which support generating a port_management_config_change
    event with subtype sl-to-vl-table-change, the driver uses that event
    to update its sl-to-vl mapping cache.  Otherwise, the driver snoops
    incoming SMP mads to update the cache.
    
    There remains the case where the FW is running in secure-host mode
    (so no QP0 packets are delivered to the driver), and the FW does not
    generate the sl2vl mapping change event. To support this case, the
    driver updates (via querying the FW) its sl2vl mapping cache when
    running in secure-host mode when it receives either a Port Up event
    or a client-reregister event (where the port is still up, but there
    may have been an opensm failover).
    OpenSM modifies the sl2vl mapping before Port Up and Client-reregister
    events occur, so if there is a mapping change the driver's cache will
    be properly updated.
    
    Fixes: 225c7b1f ("IB/mlx4: Add a driver Mellanox ConnectX InfiniBand adapters")
    Signed-off-by: default avatarJack Morgenstein <jackm@dev.mellanox.co.il>
    Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
    Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
    fd10ed8e
mlx4_ib.h 24.4 KB