i40e: fix registering XDP RxQ info

[ Upstream commit 8f497dc8a61429cc004720aa8e713743355d80cf ]

Current way of handling XDP RxQ info in i40e has a problem, where frag_size
is not updated when xsk_buff_pool is detached or when MTU is changed, this
leads to growing tail always failing for multi-buffer packets.

Couple XDP RxQ info registering with buffer allocations and unregistering
with cleaning the ring.

Fixes: a045d2f2d03d ("i40e: set xdp_rxq_info::frag_size")
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Link: https://patch.msgid.link/20260305111253.2317394-6-larysa.zaremba@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

2 files changed, 22 insertions, 17 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 31c83fc69cf4..981c01dce0cd 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3633,18 +3633,8 @@ static int i40e_configure_rx_ring(struct i40e_ring *ring)
 	if (ring->vsi->type != I40E_VSI_MAIN)
 		goto skip;
 
-	if (!xdp_rxq_info_is_reg(&ring->xdp_rxq)) {
-		err = __xdp_rxq_info_reg(&ring->xdp_rxq, ring->netdev,
-					 ring->queue_index,
-					 ring->q_vector->napi.napi_id,
-					 ring->rx_buf_len);
-		if (err)
-			return err;
-	}
-
 	ring->xsk_pool = i40e_xsk_pool(ring);
 	if (ring->xsk_pool) {
-		xdp_rxq_info_unreg(&ring->xdp_rxq);
 		ring->rx_buf_len = xsk_pool_get_rx_frame_size(ring->xsk_pool);
 		err = __xdp_rxq_info_reg(&ring->xdp_rxq, ring->netdev,
 					 ring->queue_index,
@@ -3656,17 +3646,23 @@ static int i40e_configure_rx_ring(struct i40e_ring *ring)
 						 MEM_TYPE_XSK_BUFF_POOL,
 						 NULL);
 		if (err)
-			return err;
+			goto unreg_xdp;
 		dev_info(&vsi->back->pdev->dev,
 			 "Registered XDP mem model MEM_TYPE_XSK_BUFF_POOL on Rx ring %d\n",
 			 ring->queue_index);
 
 	} else {
+		err = __xdp_rxq_info_reg(&ring->xdp_rxq, ring->netdev,
+					 ring->queue_index,
+					 ring->q_vector->napi.napi_id,
+					 ring->rx_buf_len);
+		if (err)
+			return err;
 		err = xdp_rxq_info_reg_mem_model(&ring->xdp_rxq,
 						 MEM_TYPE_PAGE_SHARED,
 						 NULL);
 		if (err)
-			return err;
+			goto unreg_xdp;
 	}
 
 skip:
@@ -3704,7 +3700,8 @@ skip:
 		dev_info(&vsi->back->pdev->dev,
 			 "Failed to clear LAN Rx queue context on Rx ring %d (pf_q %d), error: %d\n",
 			 ring->queue_index, pf_q, err);
-		return -ENOMEM;
+		err = -ENOMEM;
+		goto unreg_xdp;
 	}
 
 	/* set the context in the HMC */
@@ -3713,7 +3710,8 @@ skip:
 		dev_info(&vsi->back->pdev->dev,
 			 "Failed to set LAN Rx queue context on Rx ring %d (pf_q %d), error: %d\n",
 			 ring->queue_index, pf_q, err);
-		return -ENOMEM;
+		err = -ENOMEM;
+		goto unreg_xdp;
 	}
 
 	/* configure Rx buffer alignment */
@@ -3721,7 +3719,8 @@ skip:
 		if (I40E_2K_TOO_SMALL_WITH_PADDING) {
 			dev_info(&vsi->back->pdev->dev,
 				 "2k Rx buffer is too small to fit standard MTU and skb_shared_info\n");
-			return -EOPNOTSUPP;
+			err = -EOPNOTSUPP;
+			goto unreg_xdp;
 		}
 		clear_ring_build_skb_enabled(ring);
 	} else {
@@ -3751,6 +3750,11 @@ skip:
 	}
 
 	return 0;
+unreg_xdp:
+	if (ring->vsi->type == I40E_VSI_MAIN)
+		xdp_rxq_info_unreg(&ring->xdp_rxq);
+
+	return err;
 }
 
 /**
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index ca7517a68a2c..bca8398a6ab4 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -1469,6 +1469,9 @@ void i40e_clean_rx_ring(struct i40e_ring *rx_ring)
 	if (!rx_ring->rx_bi)
 		return;
 
+	if (xdp_rxq_info_is_reg(&rx_ring->xdp_rxq))
+		xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
+
 	if (rx_ring->xsk_pool) {
 		i40e_xsk_clean_rx_ring(rx_ring);
 		goto skip_free;
@@ -1526,8 +1529,6 @@ skip_free:
 void i40e_free_rx_resources(struct i40e_ring *rx_ring)
 {
 	i40e_clean_rx_ring(rx_ring);
-	if (rx_ring->vsi->type == I40E_VSI_MAIN)
-		xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
 	rx_ring->xdp_prog = NULL;
 	kfree(rx_ring->rx_bi);
 	rx_ring->rx_bi = NULL;