• Jakub Kicinski's avatar
    net: store port/representator id in metadata_dst · 3fcece12
    Jakub Kicinski authored
    Switches and modern SR-IOV enabled NICs may multiplex traffic from Port
    representators and control messages over single set of hardware queues.
    Control messages and muxed traffic may need ordered delivery.
    
    Those requirements make it hard to comfortably use TC infrastructure today
    unless we have a way of attaching metadata to skbs at the upper device.
    Because single set of queues is used for many netdevs stopping TC/sched
    queues of all of them reliably is impossible and lower device has to
    retreat to returning NETDEV_TX_BUSY and usually has to take extra locks on
    the fastpath.
    
    This patch attempts to enable port/representative devs to attach metadata
    to skbs which carry port id.  This way representatives can be queueless and
    all queuing can be performed at the lower netdev in the usual way.
    
    Traffic arriving on the port/representative interfaces will be have
    metadata attached and will subsequently be queued to the lower device for
    transmission.  The lower device should recognize the metadata and translate
    it to HW specific format which is most likely either a special header
    inserted before the network headers or descriptor/metadata fields.
    
    Metadata is associated with the lower device by storing the netdev pointer
    along with port id so that if TC decides to redirect or mirror the new
    netdev will not try to interpret it.
    
    This is mostly for SR-IOV devices since switches don't have lower netdevs
    today.
    Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
    Signed-off-by: default avatarSridhar Samudrala <sridhar.samudrala@intel.com>
    Signed-off-by: default avatarSimon Horman <horms@verge.net.au>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    3fcece12
dst.c 7.76 KB