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From:   Larysa Zaremba <larysa.zaremba@intel.com>
To:     bpf@vger.kernel.org
Cc:     Larysa Zaremba <larysa.zaremba@intel.com>,
        Stanislav Fomichev <sdf@google.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
        Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Tony Nguyen <anthony.l.nguyen@intel.com>,
        Anatoly Burakov <anatoly.burakov@intel.com>,
        Jesper Dangaard Brouer <brouer@redhat.com>,
        Alexander Lobakin <alexandr.lobakin@intel.com>,
        Magnus Karlsson <magnus.karlsson@gmail.com>,
        Maryam Tahhan <mtahhan@redhat.com>, xdp-hints@xdp-project.net,
        netdev@vger.kernel.org, intel-wired-lan@lists.osuosl.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 08/15] ice: Support XDP hints in AF_XDP ZC mode
Date:   Fri, 12 May 2023 17:16:32 +0200
Message-Id: <20230512151639.992033-9-larysa.zaremba@intel.com>
In-Reply-To: <20230512151639.992033-1-larysa.zaremba@intel.com>
References: <20230512151639.992033-1-larysa.zaremba@intel.com>
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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