• Mark Bloch's avatar
    IB/IPoIB: Allow setting the device address · 492a7e67
    Mark Bloch authored
    In IB networks, and specifically in IPoIB/rdmacm traffic, the device
    address of an IPoIB interface is used as a means to exchange information
    between nodes needed for communication.
    
    Currently an IPoIB interface will always be created with a device
    address based on its node GUID without a way to change that.
    
    This change adds the ability to set the device address of an IPoIB
    interface by value. We use the set mac address ndo to do that.
    
    The flow should be broken down to two:
    1) The GID value is already in the GID table,
       in this case the interface will be able to set carrier up.
    
    2) The GID value is not yet in the GID table,
       in this case the interface won't try to join the multicast group
       and will wait (listen on GID_CHANGE event) until the GID is inserted.
    
    In order to track those changes, we add a new flag:
    * IPOIB_FLAG_DEV_ADDR_SET.
    
    When set, it means the dev_addr is a based on a value in the gid
    table. this bit will be cleared upon a dev_addr change triggered
    by the user and set after validation.
    
    Per IB spec the port GUID can't change if the module is loaded.
    port GUID is the basis for GID at index 0 which is the basis for
    the default device address of a ipoib interface.
    
    The issue is that there are devices that don't follow the spec,
    they change the port GUID while HCA is powered on, so in order
    not to break userspace applications. We need to check if the
    user wanted to control the device address and we assume that
    if he sets the device address back to be based on GID index 0,
    he no longer wishs to control it.
    
    In order to track this, we add an additional flag:
    * IPOIB_FLAG_DEV_ADDR_CTRL
    
    When setting the device address, there is no validation of the upper
    twelve bytes of the device address (flags, qpn, subnet prefix) as those
    bytes are not under the control of the user.
    Signed-off-by: default avatarMark Bloch <markb@mellanox.com>
    Reviewed-by: default avatarLeon Romanovsky <leonro@mellanox.com>
    Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
    Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
    492a7e67
ipoib_verbs.c 8.53 KB