In AF_XDP ZC, xdp_buff is not stored on ring,
instead it is provided by xsk_buff_pool.
Space for metadata sources right after such buffers was already reserved
in commit 94ecc5ca4dbf ("xsk: Add cb area to struct xdp_buff_xsk").
This makes the implementation rather straightforward.
Update AF_XDP ZC packet processing to support XDP hints.
Signed-off-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
---
drivers/net/ethernet/intel/ice/ice_xsk.c | 34 ++++++++++++++++++++++--
1 file changed, 32 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index ef778b8e6d1b..6ca620b2fbdd 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -752,22 +752,51 @@ static int ice_xmit_xdp_tx_zc(struct xdp_buff *xdp,
return ICE_XDP_CONSUMED;
}
+/**
+ * ice_prepare_pkt_ctx_zc - Prepare packet context for XDP hints
+ * @xdp: xdp_buff used as input to the XDP program
+ * @eop_desc: End of packet descriptor
+ * @rx_ring: Rx ring with packet context
+ *
+ * In regular XDP, xdp_buff is placed inside the ring structure,
+ * just before the packet context, so the latter can be accessed
+ * with xdp_buff address only at all times, but in ZC mode,
+ * xdp_buffs come from the pool, so we need to reinitialize
+ * context for every packet.
+ *
+ * We can safely convert xdp_buff_xsk to ice_xdp_buff,
+ * because there are XSK_PRIV_MAX bytes reserved in xdp_buff_xsk
+ * right after xdp_buff, for our private use.
+ * XSK_CHECK_PRIV_TYPE() ensures we do not go above the limit.
+ */
+static void ice_prepare_pkt_ctx_zc(struct xdp_buff *xdp,
+ union ice_32b_rx_flex_desc *eop_desc,
+ struct ice_rx_ring *rx_ring)
+{
+ XSK_CHECK_PRIV_TYPE(struct ice_xdp_buff);
+ ((struct ice_xdp_buff *)xdp)->pkt_ctx = rx_ring->pkt_ctx;
+ ice_xdp_meta_set_desc(xdp, eop_desc);
+}
+
/**
* ice_run_xdp_zc - Executes an XDP program in zero-copy path
* @rx_ring: Rx ring
* @xdp: xdp_buff used as input to the XDP program
* @xdp_prog: XDP program to run
* @xdp_ring: ring to be used for XDP_TX action
+ * @rx_desc: packet descriptor
*
* Returns any of ICE_XDP_{PASS, CONSUMED, TX, REDIR}
*/
static int
ice_run_xdp_zc(struct ice_rx_ring *rx_ring, struct xdp_buff *xdp,
- struct bpf_prog *xdp_prog, struct ice_tx_ring *xdp_ring)
+ struct bpf_prog *xdp_prog, struct ice_tx_ring *xdp_ring,
+ union ice_32b_rx_flex_desc *rx_desc)
{
int err, result = ICE_XDP_PASS;
u32 act;
+ ice_prepare_pkt_ctx_zc(xdp, rx_desc, rx_ring);
act = bpf_prog_run_xdp(xdp_prog, xdp);
if (likely(act == XDP_REDIRECT)) {
@@ -907,7 +936,8 @@ int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget)
if (ice_is_non_eop(rx_ring, rx_desc))
continue;
- xdp_res = ice_run_xdp_zc(rx_ring, first, xdp_prog, xdp_ring);
+ xdp_res = ice_run_xdp_zc(rx_ring, first, xdp_prog, xdp_ring,
+ rx_desc);
if (likely(xdp_res & (ICE_XDP_TX | ICE_XDP_REDIR))) {
xdp_xmit |= xdp_res;
} else if (xdp_res == ICE_XDP_EXIT) {
--
2.41.0
