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  1. Mar 30, 2021
    • Andre Guedes's avatar
      igc: Add support for XDP_TX action · 73f1071c
      Andre Guedes authored 
      

Add support for XDP_TX action which enables XDP programs to transmit
back receiving frames.

I225 controller has only 4 Tx hardware queues. Since XDP programs may
not even issue an XDP_TX action, this patch doesn't reserve dedicated
queues just for XDP like other Intel drivers do. Instead, the queues
are shared between the network stack and XDP. The netdev queue lock is
used to ensure mutual exclusion.

Since frames can now be transmitted via XDP_TX, the igc_tx_buffer
structure is modified so we are able to save a reference to the xdp
frame for later clean up once the packet is transmitted. The tx_buffer
is mapped to either a skb or a xdpf so we use a union to save the skb
or xdpf pointer and have a bit in tx_flags to indicate which field to
use.

This patch has been tested with the sample app "xdp2" located in
samples/bpf/ dir.

Signed-off-by: default avatarAndre Guedes <andre.guedes@intel.com>
Signed-off-by: default avatarVedang Patel <vedang.patel@intel.com>
Signed-off-by: default avatarJithu Joseph <jithu.joseph@intel.com>
Reviewed-by: default avatarMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: default avatarDvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
      73f1071c
    • Andre Guedes's avatar
      igc: Add initial XDP support · 26575105
      Andre Guedes authored 
      Add the initial XDP support to the igc driver. For now, only XDP_PASS,
XDP_DROP, XDP_ABORTED actions are supported. Upcoming patches will add
support for the remaining XDP actions.

XDP configuration helpers are defined in a new file, igc_xdp.c. These
helpers are utilized in igc_main.c to implement the ndo_bpf callback.
XDP-related code that belongs to the driver's hot path is landed in
igc_main.c.

By default, the driver uses Rx buffers with 2 KB size. When XDP is
enabled, it uses larger buffers so we have enough space to accommodate
the headroom and tailroom required by XDP infrastructure. Also, the
driver doesn't support XDP functionality with frames that span over
multiple buffers so jumbo frames are not allowed for now.

The approach implemented follows the approach implemented in other Intel
drivers as much as possible for the sake of consistency across the
drivers.

Quick comment regarding igc_build_skb(): this patch doesn't touch it
because the function is never called. It seems its support is
incomplete/in progress. The function was added by commit 0507ef8a


("igc: Add transmit and receive fastpath and interrupt handlers") but
ring_uses_build_skb() always return False since the IGC_RING_FLAG_RX_
BUILD_SKB_ENABLED isn't set anywhere in the driver code.

This patch has been tested with the sample app "xdp1" located in
samples/bpf/ dir.

Signed-off-by: default avatarAndre Guedes <andre.guedes@intel.com>
Signed-off-by: default avatarVedang Patel <vedang.patel@intel.com>
Signed-off-by: default avatarJithu Joseph <jithu.joseph@intel.com>
Reviewed-by: default avatarMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: default avatarDvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
      26575105
  3. Mar 29, 2021