This is a note to let you know that I've just added the patch titled net: ena: Fix xdp drops handling due to multibuf packets to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-ena-fix-xdp-drops-handling-due-to-multibuf-packe.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit fe632670f23608f8e8e833d9ba5218ef77efbfa2 Author: David Arinzon <darinzon@xxxxxxxxxx> Date: Mon Dec 11 06:27:59 2023 +0000 net: ena: Fix xdp drops handling due to multibuf packets [ Upstream commit 505b1a88d311ff6f8c44a34f94e3be21745cce6f ] 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@xxxxxxxxxx> Signed-off-by: David Arinzon <darinzon@xxxxxxxxxx> Link: https://lore.kernel.org/r/20231211062801.27891-3-darinzon@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c index da83580a11391..7d4b862be783d 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -1626,20 +1626,23 @@ 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->page_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); @@ -1708,7 +1711,7 @@ 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)