From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vedang Patel Date: Mon, 8 Feb 2021 18:42:34 -0800 Subject: [Intel-wired-lan] [PATCH net-next v3 0/9] igc: Add support for AF_XDP zero-copy Message-ID: <20210209024243.23406-1-vedang.patel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: Hi all, This is the third version of this series which adds AF_XDP zero-copy support to igc driver. The main changes from v2 are: - In igc_clean_rx_ring(), clear large buffer bit after calling dma_unmap_page_attrs(). dma_unmap_page_attrs() needs the buffer size in order to unmap the page. - In igc_clean_rx_irq_zc(), the Rx hardware timestamp is needed if the BPF program returns XDP_PASS and the packet needs to be passed to the network stack. Known issues: When an XDP application is running in Tx-Only mode with Zero-Copy enabled, it is not expected to add the frames to the fill-queue. I have noticed the following two issues in this scenario: - If XDP_USE_NEED_WAKEUP flag is not set by application, igc_poll() will go into infinite loop because the buffer allocation resulting in igc_clean_rx_irq_zc() indicating that all work is not done and NAPI should keep polling. This does not occur if XDP_USE_NEED_WAKEUP flag is set. - Since there are no buffers allocated by userspace for the fill queue, there is no memory allocated for the NIC to copy the data to. If the packet received is destined to the hardware queue where XDP application is running, no packets are received even on other queues. Both these issues can be mitigated by adding a few frames to the fill queue. The second issue can also be mitigated by making sure no packets are being received on the hardware queue where Rx is running. v2 is here: https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20201223203705.78705-1-andre.guedes at intel.com/ v1 is here: https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20201217202415.77891-1-andre.guedes at intel.com/ Thanks, Vedang Andre Guedes (9): igc: Move igc_xdp_is_enabled() igc: Refactor igc_xdp_run_prog() igc: Refactor igc_clean_rx_ring() igc: Refactor XDP rxq info registration igc: Introduce tx/rx stats helpers igc: Introduce igc_unmap_tx_buffer() helper igc: Replace IGC_TX_FLAGS_XDP flag by an enum igc: Enable RX via AF_XDP zero-copy igc: Enable TX via AF_XDP zero-copy drivers/net/ethernet/intel/igc/igc.h | 33 +- drivers/net/ethernet/intel/igc/igc_base.h | 2 + drivers/net/ethernet/intel/igc/igc_main.c | 651 ++++++++++++++++++---- drivers/net/ethernet/intel/igc/igc_xdp.c | 107 +++- drivers/net/ethernet/intel/igc/igc_xdp.h | 8 +- 5 files changed, 674 insertions(+), 127 deletions(-) -- 2.17.1