diff mbox series

[v1,net,2/4] net: ena: Fix xdp drops handling due to multibuf packets

Message ID 20231210083056.30357-3-darinzon@amazon.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series ENA driver XDP bug fixes | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success SINGLE THREAD; Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1115 this patch: 1115
netdev/cc_maintainers fail 1 blamed authors not CCed: sameehj@amazon.com; 8 maintainers not CCed: daniel@iogearbox.net bpf@vger.kernel.org ast@kernel.org pabeni@redhat.com hawk@kernel.org sameehj@amazon.com john.fastabend@gmail.com edumazet@google.com
netdev/build_clang success Errors and warnings before: 1142 this patch: 1142
netdev/verify_signedoff fail author Signed-off-by missing
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1142 this patch: 1142
netdev/checkpatch warning WARNING: line length of 83 exceeds 80 columns WARNING: line length of 91 exceeds 80 columns WARNING: line length of 93 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

David Arinzon Dec. 10, 2023, 8:30 a.m. UTC 
From: David Arinzon <darinzon@amazon.com>

Current xdp code drops packets larger than ENA_XDP_MAX_MTU.
This is an incorrect condition since the problem is not the
size of the packet, rather the number of buffers it contains.

This commit:

1. Identifies and drops XDP multi-buffer packets at the
   beginning of the function.
2. Increases the xdp drop statistic when this drop occurs.
3. Adds a one-time print that such drops are happening to
   give better indication to the user.

Fixes: 838c93dc5449 ("net: ena: implement XDP drop support")
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_netdev.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 9884ef3..c7bc572 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -1672,20 +1672,23 @@  static void ena_set_rx_hash(struct ena_ring *rx_ring,
 	}
 }
 
-static int ena_xdp_handle_buff(struct ena_ring *rx_ring, struct xdp_buff *xdp)
+static int ena_xdp_handle_buff(struct ena_ring *rx_ring, struct xdp_buff *xdp, u16 num_descs)
 {
 	struct ena_rx_buffer *rx_info;
 	int ret;
 
+	/* XDP multi-buffer packets not supported */
+	if (unlikely(num_descs > 1)) {
+		netdev_err_once(rx_ring->adapter->netdev,
+				"xdp: dropped unsupported multi-buffer packets\n");
+		ena_increase_stat(&rx_ring->rx_stats.xdp_drop, 1, &rx_ring->syncp);
+		return ENA_XDP_DROP;
+	}
+
 	rx_info = &rx_ring->rx_buffer_info[rx_ring->ena_bufs[0].req_id];
 	xdp_prepare_buff(xdp, page_address(rx_info->page),
 			 rx_info->buf_offset,
 			 rx_ring->ena_bufs[0].len, false);
-	/* If for some reason we received a bigger packet than
-	 * we expect, then we simply drop it
-	 */
-	if (unlikely(rx_ring->ena_bufs[0].len > ENA_XDP_MAX_MTU))
-		return ENA_XDP_DROP;
 
 	ret = ena_xdp_execute(rx_ring, xdp);
 
@@ -1754,7 +1757,7 @@  static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi,
 			  ena_rx_ctx.l4_proto, ena_rx_ctx.hash);
 
 		if (ena_xdp_present_ring(rx_ring))
-			xdp_verdict = ena_xdp_handle_buff(rx_ring, &xdp);
+			xdp_verdict = ena_xdp_handle_buff(rx_ring, &xdp, ena_rx_ctx.descs);
 
 		/* allocate skb and fill it */
 		if (xdp_verdict == ENA_XDP_PASS)