[PATCH v2 iwl-next] ice: allow hot-swapping XDP programs
From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Date: 2023-06-13 23:15:36
Also in:
intel-wired-lan
Subsystem:
intel ethernet drivers, networking drivers, the rest · Maintainers:
Tony Nguyen, Przemek Kitszel, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Currently ice driver's .ndo_bpf callback brings interface down and up independently of XDP resources' presence. This is only needed when either these resources have to be configured or removed. It means that if one is switching XDP programs on-the-fly with running traffic, packets will be dropped. To avoid this, compare early on ice_xdp_setup_prog() state of incoming bpf_prog pointer vs the bpf_prog pointer that is already assigned to VSI. Do the swap in case VSI has bpf_prog and incoming one are non-NULL. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> --- v1->v2: - fix missing brace (sigh) drivers/net/ethernet/intel/ice/ice_main.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index a1f7c8edc22f..dba1f7709e8b 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c@@ -2924,6 +2924,12 @@ ice_xdp_setup_prog(struct ice_vsi *vsi, struct bpf_prog *prog, } } + /* hot swap progs and avoid toggling link */ + if (ice_is_xdp_ena_vsi(vsi) == !!prog) { + ice_vsi_assign_bpf_prog(vsi, prog); + return 0; + } + /* need to stop netdev while setting up the program for Rx rings */ if (if_running && !test_and_set_bit(ICE_VSI_DOWN, vsi->state)) { ret = ice_down(vsi);
@@ -2956,13 +2962,6 @@ ice_xdp_setup_prog(struct ice_vsi *vsi, struct bpf_prog *prog, xdp_ring_err = ice_realloc_zc_buf(vsi, false); if (xdp_ring_err) NL_SET_ERR_MSG_MOD(extack, "Freeing XDP Rx resources failed"); - } else { - /* safe to call even when prog == vsi->xdp_prog as - * dev_xdp_install in net/core/dev.c incremented prog's - * refcount so corresponding bpf_prog_put won't cause - * underflow - */ - ice_vsi_assign_bpf_prog(vsi, prog); } if (if_running)
--
2.34.1