ice: unify xdp_rings accesses

There has been a long lasting issue of improper xdp_rings indexing for
XDP_TX and XDP_REDIRECT actions. Given that currently rx_ring->q_index
is mixed with smp_processor_id(), there could be a situation where Tx
descriptors are produced onto XDP Tx ring, but tail is never bumped -
for example pin a particular queue id to non-matching IRQ line.

Address this problem by ignoring the user ring count setting and always
initialize the xdp_rings array to be of num_possible_cpus() size. Then,
always use the smp_processor_id() as an index to xdp_rings array. This
provides serialization as at given time only a single softirq can run on
a particular CPU.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index 0415513..58fad5f 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -3215,7 +3215,7 @@ int ice_vsi_rebuild(struct ice_vsi *vsi, bool init_vsi)
 
                ice_vsi_map_rings_to_vectors(vsi);
                if (ice_is_xdp_ena_vsi(vsi)) {
-                       vsi->num_xdp_txq = vsi->alloc_rxq;
+                       vsi->num_xdp_txq = num_possible_cpus();
                        ret = ice_prepare_xdp_rings(vsi, vsi->xdp_prog);
                        if (ret)
                                goto err_vectors;

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index e4c12a8..856ae22 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -2638,7 +2638,7 @@ ice_xdp_setup_prog(struct ice_vsi *vsi, struct bpf_prog *prog,
        }
 
        if (!ice_is_xdp_ena_vsi(vsi) && prog) {
-               vsi->num_xdp_txq = vsi->alloc_rxq;
+               vsi->num_xdp_txq = num_possible_cpus();
                xdp_ring_err = ice_prepare_xdp_rings(vsi, prog);
                if (xdp_ring_err)
                        NL_SET_ERR_MSG_MOD(extack, "Setting up XDP Tx resources failed");

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
index d6d71f8..bc64610 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
@@ -297,7 +297,7 @@ void ice_finalize_xdp_rx(struct ice_rx_ring *rx_ring, unsigned int xdp_res)
 
        if (xdp_res & ICE_XDP_TX) {
                struct ice_tx_ring *xdp_ring =
-                       rx_ring->vsi->xdp_rings[rx_ring->q_index];
+                       rx_ring->vsi->xdp_rings[smp_processor_id()];
 
                ice_xdp_ring_update_tail(xdp_ring);
        }