[PATCH net v3] net: libwx: fix PM suspend/resume flow for VF drivers
From: Mengyuan Lou <mengyuanlou@net-swift.com>
Date: 2026-09-04 08:53:39
Subsystem:
networking drivers, the rest, wangxun ethernet driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Jiawen Wu, Mengyuan Lou
Rework wxvf_suspend() and wxvf_resume() to handle interface lifecycle
transitions safely under rtnl_lock() and eliminate resource races.
In wxvf_suspend(), if the netdevice is running, invoke wxvf_close() to
quiesce DMA engines, disable NAPI, and release IRQs/rings cleanly prior
to clearing PCI bus mastering and disabling the device.
In wxvf_resume(), avoid partial hardware re-initialization on active
queues. If the device was running before suspend, defer complete queue
and interrupt setup to a new reset subtask flag WX_FLAG_NEED_REOPEN,
which safely invokes wxvf_open() under rtnl_lock(). Provide error
unwinding inside wxvf_reopen_subtask() if re-opening fails.
Fixes: 377d180bd71c ("net: wangxun: add txgbevf build")
Signed-off-by: Mengyuan Lou <mengyuanlou@net-swift.com>
---
Changelogs:
v3:
- Fix DMA-after-free and UAF races in wxvf_suspend() by invoking
wxvf_close() when running, ensuring DMA engines are stopped and
NAPI/IRQs/rings are cleanly freed before clearing PCI state.
- Replace manual resource allocation in wxvf_resume() with deferred
reopening via WX_FLAG_NEED_REOPEN, scheduling wxvf_reopen_subtask() to
run full wxvf_open() sequence under rtnl_lock().
- Move timer/work synchronization after rtnl_lock() release in
wxvf_suspend() to prevent service tasks from re-arming the timer.
- Add error unwinding in wxvf_reopen_subtask() to set WX_STATE_DOWN,
clear bus mastering, and log errors if reopen fails.
- Skip wxvf_link_config_subtask() when WX_STATE_DOWN is set to prevent
link updates on downed interfaces.
v2: https://lore.kernel.org/netdev/20260829091423.83097-1-mengyuanlou@net-swift.com/ (local)
- Refactored the suspend and resume logic to eliminate full netdevice close/open
cycles in favor of lightweight interrupt and queue manipulation:
* In wxvf_suspend(), replaced wxvf_close() with explicit queue stopping
(netif_tx_disable), carrier drop, NAPI disabling (wx_napi_disable_all), IRQ
releasing (wx_free_irq), and resource freeing (wx_free_resources).
* In wxvf_resume(), replaced wxvf_open() with granular resource allocation
(wx_setup_resources), MSI-X IRQ requesting (wx_request_msix_irqs_vf), and deferred
hardware reconfiguration via WX_FLAG_NEED_DO_RESET flag.
- Dropped the addition of device_link_add() to parent PF in ngbevf and txgbevf probe()
paths to keep the patch focused strictly on libwx PM suspend/resume flow.
v1: https://lore.kernel.org/netdev/20260826095243.16939-1-mengyuanlou@net-swift.com/ (local)
---
drivers/net/ethernet/wangxun/libwx/wx_type.h | 1 +
.../net/ethernet/wangxun/libwx/wx_vf_common.c | 57 ++++++++++++++++++-
2 files changed, 55 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/wangxun/libwx/wx_type.h b/drivers/net/ethernet/wangxun/libwx/wx_type.h
index 2eba5ab59925..1b18b069decc 100644
--- a/drivers/net/ethernet/wangxun/libwx/wx_type.h
+++ b/drivers/net/ethernet/wangxun/libwx/wx_type.h@@ -1288,6 +1288,7 @@ enum wx_pf_flags { WX_FLAG_NEED_MODULE_RESET, WX_FLAG_NEED_UPDATE_LINK, WX_FLAG_NEED_DO_RESET, + WX_FLAG_NEED_REOPEN, WX_FLAG_RX_MERGE_ENABLED, WX_FLAG_TXHEAD_WB_ENABLED, WX_FLAG_NEED_PCIE_RECOVERY,
diff --git a/drivers/net/ethernet/wangxun/libwx/wx_vf_common.c b/drivers/net/ethernet/wangxun/libwx/wx_vf_common.c
index 26de78e9a69e..3e55738e2096 100644
--- a/drivers/net/ethernet/wangxun/libwx/wx_vf_common.c
+++ b/drivers/net/ethernet/wangxun/libwx/wx_vf_common.c@@ -16,9 +16,16 @@ int wxvf_suspend(struct device *dev_d) struct pci_dev *pdev = to_pci_dev(dev_d); struct wx *wx = pci_get_drvdata(pdev); + rtnl_lock(); netif_device_detach(wx->netdev); + if (netif_running(wx->netdev)) + wxvf_close(wx->netdev); wx_clear_interrupt_scheme(wx); + pci_clear_master(pdev); pci_disable_device(pdev); + rtnl_unlock(); + timer_delete_sync(&wx->service_timer); + cancel_work_sync(&wx->service_task); return 0; }
@@ -34,11 +41,25 @@ int wxvf_resume(struct device *dev_d) { struct pci_dev *pdev = to_pci_dev(dev_d); struct wx *wx = pci_get_drvdata(pdev); + int err; - pci_set_master(pdev); - wx_init_interrupt_scheme(wx); - netif_device_attach(wx->netdev); + err = pci_enable_device_mem(pdev); + if (err) { + dev_err(&pdev->dev, "Cannot enable PCI device from suspend\n"); + return err; + } + rtnl_lock(); + if (netif_running(wx->netdev)) { + clear_bit(WX_STATE_DOWN, wx->state); + clear_bit(WX_STATE_SERVICE_SCHED, wx->state); + mod_timer(&wx->service_timer, jiffies + HZ); + set_bit(WX_FLAG_NEED_REOPEN, wx->flags); + } else { + pci_set_master(pdev); + netif_device_attach(wx->netdev); + } + rtnl_unlock(); return 0; } EXPORT_SYMBOL(wxvf_resume);
@@ -388,6 +409,9 @@ static void wxvf_link_config_subtask(struct wx *wx) { struct net_device *netdev = wx->netdev; + if (test_bit(WX_STATE_DOWN, wx->state)) + return; + wxvf_watchdog_update_link(wx); if (wx->link) { if (netif_carrier_ok(netdev))
@@ -403,10 +427,37 @@ static void wxvf_link_config_subtask(struct wx *wx) } } +static void wxvf_reopen_subtask(struct wx *wx) +{ + if (!test_bit(WX_FLAG_NEED_REOPEN, wx->flags)) + return; + + rtnl_lock(); + pci_set_master(wx->pdev); + if (wx_init_interrupt_scheme(wx)) + goto out; + if (wxvf_open(wx->netdev)) + goto out_clear_scheme; + clear_bit(WX_FLAG_NEED_REOPEN, wx->flags); + netif_device_attach(wx->netdev); + rtnl_unlock(); + return; + +out_clear_scheme: + wx_clear_interrupt_scheme(wx); +out: + pci_clear_master(wx->pdev); + clear_bit(WX_FLAG_NEED_REOPEN, wx->flags); + set_bit(WX_STATE_DOWN, wx->state); + rtnl_unlock(); + dev_err(&wx->pdev->dev, "Failed to reopen device\n"); +} + static void wxvf_service_task(struct work_struct *work) { struct wx *wx = container_of(work, struct wx, service_task); + wxvf_reopen_subtask(wx); wxvf_link_config_subtask(wx); wxvf_reset_subtask(wx); wx_service_event_complete(wx);
--
2.30.1