On Thu, Oct 09, 2025 at 03:28:30PM -0400, Nabil S. Alramli wrote: > This commit adds support for `ndo_xdp_xmit` in skb mode in the ixgbe > ethernet driver, by allowing the call to continue to transmit the packets > using `dev_direct_xmit`. > > Previously, the driver did not support the operation in skb mode. The > handler `ixgbe_xdp_xmit` had the following condition: > > ``` > ring = adapter->xdp_prog ? ixgbe_determine_xdp_ring(adapter) : NULL; > if (unlikely(!ring)) > return -ENXIO; > ``` > > That only works in native mode. In skb mode, `adapter->xdp_prog == NULL` so > the call returned an error, which prevented the ability to send packets > using `bpf_prog_test_run_opts` with the `BPF_F_TEST_XDP_LIVE_FRAMES` flag.
Hi Nabil, What stops you from loading a dummy XDP program to interface? This has been an approach that we follow when we want to use anything that utilizes XDP resources (XDP Tx queues). > > Signed-off-by: Nabil S. Alramli <[email protected]> > --- > drivers/net/ethernet/intel/ixgbe/ixgbe.h | 8 ++++ > drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 43 +++++++++++++++++-- > 2 files changed, 47 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h > b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > index e6a380d4929b..26c378853755 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > @@ -846,6 +846,14 @@ struct ixgbe_ring *ixgbe_determine_xdp_ring(struct > ixgbe_adapter *adapter) > return adapter->xdp_ring[index]; > } > > +static inline > +struct ixgbe_ring *ixgbe_determine_tx_ring(struct ixgbe_adapter *adapter) > +{ > + int index = ixgbe_determine_xdp_q_idx(smp_processor_id()); > + > + return adapter->tx_ring[index]; > +} > + > static inline u8 ixgbe_max_rss_indices(struct ixgbe_adapter *adapter) > { > switch (adapter->hw.mac.type) { > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > index 467f81239e12..fed70cbdb1b2 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > @@ -10748,7 +10748,8 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int > n, > /* During program transitions its possible adapter->xdp_prog is assigned > * but ring has not been configured yet. In this case simply abort xmit. > */ > - ring = adapter->xdp_prog ? ixgbe_determine_xdp_ring(adapter) : NULL; > + ring = adapter->xdp_prog ? ixgbe_determine_xdp_ring(adapter) : > + ixgbe_determine_tx_ring(adapter); > if (unlikely(!ring)) > return -ENXIO; > > @@ -10762,9 +10763,43 @@ static int ixgbe_xdp_xmit(struct net_device *dev, > int n, > struct xdp_frame *xdpf = frames[i]; > int err; > > - err = ixgbe_xmit_xdp_ring(ring, xdpf); > - if (err != IXGBE_XDP_TX) > - break; > + if (adapter->xdp_prog) { > + err = ixgbe_xmit_xdp_ring(ring, xdpf); > + if (err != IXGBE_XDP_TX) > + break; > + } else { > + struct xdp_buff xdp = {0}; > + unsigned int metasize = 0; > + unsigned int size = 0; > + unsigned int truesize = 0; > + struct sk_buff *skb = NULL; > + > + xdp_convert_frame_to_buff(xdpf, &xdp); > + size = xdp.data_end - xdp.data; > + metasize = xdp.data - xdp.data_meta; > + truesize = SKB_DATA_ALIGN(xdp.data_end - > xdp.data_hard_start) + > + SKB_DATA_ALIGN(sizeof(struct > skb_shared_info)); > + > + skb = napi_alloc_skb(&ring->q_vector->napi, truesize); > + if (likely(skb)) { > + skb_reserve(skb, xdp.data - > xdp.data_hard_start); > + skb_put_data(skb, xdp.data, size); > + build_skb_around(skb, skb->data, truesize); > + if (metasize) > + skb_metadata_set(skb, metasize); > + skb->dev = dev; > + skb->queue_mapping = ring->queue_index; > + > + err = dev_direct_xmit(skb, ring->queue_index); > + if (!dev_xmit_complete(err)) > + break; > + } else { > + break; > + } > + > + xdp_return_frame_rx_napi(xdpf); > + } > + > nxmit++; > } > > -- > 2.43.0 > >
