[PATCH RESEND bpf-next 08/15] ice: Support XDP hints in AF_XDP ZC mode

Larysa Zaremba
2023-05-12T15:29:03Z

In AF_XDP ZC, xdp_buff is not stored on ring,
instead it is provided by xsk_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@intel.com>
---
drivers/net/ethernet/intel/ice/ice_xsk.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index 3b80aed5d47a..7f5ce3529666 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -708,16 +708,25 @@ static int ice_xmit_xdp_tx_zc(struct xdp_buff *xdp,
* @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;

+ /* 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.
+ * Macro insures we do not go above the limit.
+ */
+ XSK_CHECK_PRIV_TYPE(struct ice_xdp_buff);
+ ice_xdp_set_meta_srcs(xdp, rx_desc, rx_ring);
act = bpf_prog_run_xdp(xdp_prog, xdp);

if (likely(act == XDP_REDIRECT)) {
@@ -816,7 +825,8 @@ int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget)
xsk_buff_set_size(xdp, size);
xsk_buff_dma_sync_for_cpu(xdp, rx_ring->xsk_pool);

- xdp_res = ice_run_xdp_zc(rx_ring, xdp, xdp_prog, xdp_ring);
+ xdp_res = ice_run_xdp_zc(rx_ring, xdp, 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) {
--
2.35.3