Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Larysa Zaremba <larysa.zaremba@intel.com>
To:     intel-wired-lan@lists.osuosl.org
Cc:     Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Tony Nguyen <anthony.l.nguyen@intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        bpf@vger.kernel.org, Larysa Zaremba <larysa.zaremba@intel.com>,
        Alexander Lobakin <alexandr.lobakin@intel.com>
Subject: [PATCH net] ice: Fix ice_xdp_xmit() when XDP TX queue number is not sufficient
Date:   Mon, 19 Sep 2022 15:43:46 +0200
Message-Id: <20220919134346.25030-1-larysa.zaremba@intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The original patch added the static branch to handle the situation,
when assigning an XDP TX queue to every CPU is not possible,
so they have to be shared.

However, in the XDP transmit handler ice_xdp_xmit(), an error was
returned in such cases even before static condition was checked,
thus making queue sharing still impossible.

Fixes: 22bf877e528f ("ice: introduce XDP_TX fallback path")
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_txrx.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index 42b42f4b21ef..a5a0c9706b5a 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -610,7 +610,7 @@ ice_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
 	if (test_bit(ICE_VSI_DOWN, vsi->state))
 		return -ENETDOWN;
 
-	if (!ice_is_xdp_ena_vsi(vsi) || queue_index >= vsi->num_xdp_txq)
+	if (!ice_is_xdp_ena_vsi(vsi))
 		return -ENXIO;
 
 	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
@@ -621,6 +621,9 @@ ice_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
 		xdp_ring = vsi->xdp_rings[queue_index];
 		spin_lock(&xdp_ring->tx_lock);
 	} else {
+		/* Generally, should not happen */
+		if (unlikely(queue_index >= vsi->num_xdp_txq))
+			return -ENXIO;
 		xdp_ring = vsi->xdp_rings[queue_index];
 	}
 
-- 
2.35.3