[net-next,0/4] gve: Add XDP support for GQI-QPL format

Message

Praveen Kaligineedi Feb. 7, 2023, 9 p.m. UTC

Adding support for XDP DROP, PASS, TX, REDIRECT for GQI QPL format.
Add AF_XDP zero-copy support.

When an XDP program is installed, dedicated TX queues are created to
handle XDP traffic. The user needs to ensure that the number of 
configured TX queues is equal to the number of configured RX queues; and
the number of TX/RX queues is less than or equal to half the maximum
number of TX/RX queues.

The XDP traffic from AF_XDP sockets and from other NICs (arriving via
XDP_REDIRECT) will also egress through the dedicated XDP TX queues.

Although these changes support AF_XDP socket in zero-copy mode, there is
still a copy happening within the driver between XSK buffer pool and QPL
bounce buffers in GQI-QPL format.

The following example demonstrates how the XDP packets are mapped to
TX queues:

Example configuration:
Max RX queues : 2N, Max TX queues : 2N
Configured RX queues : N, Configured TX queues : N

TX queue mapping:
TX queues with queue id 0,...,N-1 will handle traffic from the stack.
TX queues with queue id N,...,2N-1 will handle XDP traffic.

For the XDP packets transmitted using XDP_TX action:
<Egress TX queue id> = N + <Ingress RX queue id>

For the XDP packets that arrive from other NICs via XDP_REDIRECT action:
<Egress TX queue id> = N + ( smp_processor_id % N )

For AF_XDP zero-copy mode:
<Egress TX queue id> = N + <AF_XDP TX queue id>

Praveen Kaligineedi (4):
  gve: XDP support GQI-QPL: helper function changes
  gve: Add XDP DROP and TX support for GQI-QPL format
  gve: Add XDP REDIRECT support for GQI-QPL format
  gve: Add AF_XDP zero-copy support for GQI-QPL format

 drivers/net/ethernet/google/gve/gve.h         |  50 ++-
 drivers/net/ethernet/google/gve/gve_ethtool.c |  91 +++--
 drivers/net/ethernet/google/gve/gve_main.c    | 325 +++++++++++++++++-
 drivers/net/ethernet/google/gve/gve_rx.c      | 143 +++++++-
 drivers/net/ethernet/google/gve/gve_rx_dqo.c  |   2 +-
 drivers/net/ethernet/google/gve/gve_tx.c      | 272 +++++++++++++--
 drivers/net/ethernet/google/gve/gve_utils.c   |   6 +-
 drivers/net/ethernet/google/gve/gve_utils.h   |   3 +-
 8 files changed, 823 insertions(+), 69 deletions(-)