From 4d4d9ef9dfee877d494e5418f68a1016ef08cad6 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Tue, 19 Aug 2025 15:19:57 -0700 Subject: [PATCH 1/3] ixgbe: xsk: resolve the negative overflow of budget in ixgbe_xmit_zc Resolve the budget negative overflow which leads to returning true in ixgbe_xmit_zc even when the budget of descs are thoroughly consumed. Before this patch, when the budget is decreased to zero and finishes sending the last allowed desc in ixgbe_xmit_zc, it will always turn back and enter into the while() statement to see if it should keep processing packets, but in the meantime it unexpectedly decreases the value again to 'unsigned int (0--)', namely, UINT_MAX. Finally, the ixgbe_xmit_zc returns true, showing 'we complete cleaning the budget'. That also means 'clean_complete = true' in ixgbe_poll. The true theory behind this is if that budget number of descs are consumed, it implies that we might have more descs to be done. So we should return false in ixgbe_xmit_zc to tell napi poll to find another chance to start polling to handle the rest of descs. On the contrary, returning true here means job done and we know we finish all the possible descs this time and we don't intend to start a new napi poll. It is apparently against our expectations. Please also see how ixgbe_clean_tx_irq() handles the problem: it uses do..while() statement to make sure the budget can be decreased to zero at most and the negative overflow never happens. The patch adds 'likely' because we rarely would not hit the loop condition since the standard budget is 256. Fixes: 8221c5eba8c1 ("ixgbe: add AF_XDP zero-copy Tx support") Signed-off-by: Jason Xing Reviewed-by: Larysa Zaremba Reviewed-by: Paul Menzel Reviewed-by: Aleksandr Loktionov Tested-by: Priya Singh Signed-off-by: Tony Nguyen Link: https://patch.msgid.link/20250819222000.3504873-4-anthony.l.nguyen@intel.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c index ac58964b2f08..7b941505a9d0 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c @@ -398,7 +398,7 @@ static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget) dma_addr_t dma; u32 cmd_type; - while (budget-- > 0) { + while (likely(budget)) { if (unlikely(!ixgbe_desc_unused(xdp_ring))) { work_done = false; break; @@ -433,6 +433,8 @@ static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget) xdp_ring->next_to_use++; if (xdp_ring->next_to_use == xdp_ring->count) xdp_ring->next_to_use = 0; + + budget--; } if (tx_desc) { From f3d9f7fa7f5dbfd4fdb1e69c25fc5627700d19dd Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Tue, 19 Aug 2025 15:19:58 -0700 Subject: [PATCH 2/3] ixgbe: fix ndo_xdp_xmit() workloads MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently ixgbe driver checks periodically in its watchdog subtask if there is anything to be transmitted (considering both Tx and XDP rings) under state of carrier not being 'ok'. Such event is interpreted as Tx hang and therefore results in interface reset. This is currently problematic for ndo_xdp_xmit() as it is allowed to produce descriptors when interface is going through reset or its carrier is turned off. Furthermore, XDP rings should not really be objects of Tx hang detection. This mechanism is rather a matter of ndo_tx_timeout() being called from dev_watchdog against Tx rings exposed to networking stack. Taking into account issues described above, let us have a two fold fix - do not respect XDP rings in local ixgbe watchdog and do not produce Tx descriptors in ndo_xdp_xmit callback when there is some problem with carrier currently. For now, keep the Tx hang checks in clean Tx irq routine, but adjust it to not execute for XDP rings. Cc: Tobias Böhm Reported-by: Marcus Wichelmann Closes: https://lore.kernel.org/netdev/eca1880f-253a-4955-afe6-732d7c6926ee@hetzner-cloud.de/ Fixes: 6453073987ba ("ixgbe: add initial support for xdp redirect") Fixes: 33fdc82f0883 ("ixgbe: add support for XDP_TX action") Reviewed-by: Aleksandr Loktionov Tested-by: Marcus Wichelmann Signed-off-by: Maciej Fijalkowski Signed-off-by: Tony Nguyen Link: https://patch.msgid.link/20250819222000.3504873-5-anthony.l.nguyen@intel.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 34 ++++++------------- 1 file changed, 11 insertions(+), 23 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 6122a0abb41f..80e6a2ef1350 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -968,10 +968,6 @@ static void ixgbe_update_xoff_rx_lfc(struct ixgbe_adapter *adapter) for (i = 0; i < adapter->num_tx_queues; i++) clear_bit(__IXGBE_HANG_CHECK_ARMED, &adapter->tx_ring[i]->state); - - for (i = 0; i < adapter->num_xdp_queues; i++) - clear_bit(__IXGBE_HANG_CHECK_ARMED, - &adapter->xdp_ring[i]->state); } static void ixgbe_update_xoff_received(struct ixgbe_adapter *adapter) @@ -1214,7 +1210,7 @@ static void ixgbe_pf_handle_tx_hang(struct ixgbe_ring *tx_ring, struct ixgbe_adapter *adapter = netdev_priv(tx_ring->netdev); struct ixgbe_hw *hw = &adapter->hw; - e_err(drv, "Detected Tx Unit Hang%s\n" + e_err(drv, "Detected Tx Unit Hang\n" " Tx Queue <%d>\n" " TDH, TDT <%x>, <%x>\n" " next_to_use <%x>\n" @@ -1222,16 +1218,14 @@ static void ixgbe_pf_handle_tx_hang(struct ixgbe_ring *tx_ring, "tx_buffer_info[next_to_clean]\n" " time_stamp <%lx>\n" " jiffies <%lx>\n", - ring_is_xdp(tx_ring) ? " (XDP)" : "", tx_ring->queue_index, IXGBE_READ_REG(hw, IXGBE_TDH(tx_ring->reg_idx)), IXGBE_READ_REG(hw, IXGBE_TDT(tx_ring->reg_idx)), tx_ring->next_to_use, next, tx_ring->tx_buffer_info[next].time_stamp, jiffies); - if (!ring_is_xdp(tx_ring)) - netif_stop_subqueue(tx_ring->netdev, - tx_ring->queue_index); + netif_stop_subqueue(tx_ring->netdev, + tx_ring->queue_index); } /** @@ -1451,6 +1445,9 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_q_vector *q_vector, total_bytes); adapter->tx_ipsec += total_ipsec; + if (ring_is_xdp(tx_ring)) + return !!budget; + if (check_for_tx_hang(tx_ring) && ixgbe_check_tx_hang(tx_ring)) { if (adapter->hw.mac.type == ixgbe_mac_e610) ixgbe_handle_mdd_event(adapter, tx_ring); @@ -1468,9 +1465,6 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_q_vector *q_vector, return true; } - if (ring_is_xdp(tx_ring)) - return !!budget; - #define TX_WAKE_THRESHOLD (DESC_NEEDED * 2) txq = netdev_get_tx_queue(tx_ring->netdev, tx_ring->queue_index); if (!__netif_txq_completed_wake(txq, total_packets, total_bytes, @@ -7974,12 +7968,9 @@ static void ixgbe_check_hang_subtask(struct ixgbe_adapter *adapter) return; /* Force detection of hung controller */ - if (netif_carrier_ok(adapter->netdev)) { + if (netif_carrier_ok(adapter->netdev)) for (i = 0; i < adapter->num_tx_queues; i++) set_check_for_tx_hang(adapter->tx_ring[i]); - for (i = 0; i < adapter->num_xdp_queues; i++) - set_check_for_tx_hang(adapter->xdp_ring[i]); - } if (!(adapter->flags & IXGBE_FLAG_MSIX_ENABLED)) { /* @@ -8199,13 +8190,6 @@ static bool ixgbe_ring_tx_pending(struct ixgbe_adapter *adapter) return true; } - for (i = 0; i < adapter->num_xdp_queues; i++) { - struct ixgbe_ring *ring = adapter->xdp_ring[i]; - - if (ring->next_to_use != ring->next_to_clean) - return true; - } - return false; } @@ -11005,6 +10989,10 @@ static int ixgbe_xdp_xmit(struct net_device *dev, int n, if (unlikely(test_bit(__IXGBE_DOWN, &adapter->state))) return -ENETDOWN; + if (!netif_carrier_ok(adapter->netdev) || + !netif_running(adapter->netdev)) + return -ENETDOWN; + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) return -EINVAL; From 1468c1f97cf32418e34dbb40b784ed9333b9e123 Mon Sep 17 00:00:00 2001 From: ValdikSS Date: Tue, 19 Aug 2025 15:19:59 -0700 Subject: [PATCH 3/3] igc: fix disabling L1.2 PCI-E link substate on I226 on init Device ID comparison in igc_is_device_id_i226 is performed before the ID is set, resulting in always failing check on init. Before the patch: * L1.2 is not disabled on init * L1.2 is properly disabled after suspend-resume cycle With the patch: * L1.2 is properly disabled both on init and after suspend-resume How to test: Connect to the 1G link with 300+ mbit/s Internet speed, and run the download speed test, such as: curl -o /dev/null http://speedtest.selectel.ru/1GB Without L1.2 disabled, the speed would be no more than ~200 mbit/s. With L1.2 disabled, the speed would reach 1 gbit/s. Note: it's required that the latency between your host and the remote be around 3-5 ms, the test inside LAN (<1 ms latency) won't trigger the issue. Link: https://lore.kernel.org/intel-wired-lan/15248b4f-3271-42dd-8e35-02bfc92b25e1@intel.com Fixes: 0325143b59c6 ("igc: disable L1.2 PCI-E link substate to avoid performance issue") Signed-off-by: ValdikSS Reviewed-by: Vitaly Lifshits Reviewed-by: Paul Menzel Signed-off-by: Tony Nguyen Link: https://patch.msgid.link/20250819222000.3504873-6-anthony.l.nguyen@intel.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/intel/igc/igc_main.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 458e5eaa92e5..e79b14d50b24 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -7149,6 +7149,13 @@ static int igc_probe(struct pci_dev *pdev, adapter->port_num = hw->bus.func; adapter->msg_enable = netif_msg_init(debug, DEFAULT_MSG_ENABLE); + /* PCI config space info */ + hw->vendor_id = pdev->vendor; + hw->device_id = pdev->device; + hw->revision_id = pdev->revision; + hw->subsystem_vendor_id = pdev->subsystem_vendor; + hw->subsystem_device_id = pdev->subsystem_device; + /* Disable ASPM L1.2 on I226 devices to avoid packet loss */ if (igc_is_device_id_i226(hw)) pci_disable_link_state(pdev, PCIE_LINK_STATE_L1_2); @@ -7175,13 +7182,6 @@ static int igc_probe(struct pci_dev *pdev, netdev->mem_start = pci_resource_start(pdev, 0); netdev->mem_end = pci_resource_end(pdev, 0); - /* PCI config space info */ - hw->vendor_id = pdev->vendor; - hw->device_id = pdev->device; - hw->revision_id = pdev->revision; - hw->subsystem_vendor_id = pdev->subsystem_vendor; - hw->subsystem_device_id = pdev->subsystem_device; - /* Copy the default MAC and PHY function pointers */ memcpy(&hw->mac.ops, ei->mac_ops, sizeof(hw->mac.ops)); memcpy(&hw->phy.ops, ei->phy_ops, sizeof(hw->phy.ops));