Re: [Intel-wired-lan] [PATCH 1/5] idpf: skip getting/setting ring params if vport is NULL during HW reset
From: Paul Menzel <hidden>
Date: 2026-01-07 05:30:54
Also in:
intel-wired-lan, lkml
Dear Li, Thank you for your patch. Am 07.01.26 um 02:04 schrieb Li Li via Intel-wired-lan:
When an idpf HW reset is triggered, it clears the vport but does
not clear the netdev held by vport:
// In idpf_vport_dealloc() called by idpf_init_hard_reset(),
// idpf_init_hard_reset() sets IDPF_HR_RESET_IN_PROG, so
// idpf_decfg_netdev() doesn't get called.No need to format this as code comments. At least it confused me a little.
if (!test_bit(IDPF_HR_RESET_IN_PROG, adapter->flags))
idpf_decfg_netdev(vport);
// idpf_decfg_netdev() would clear netdev but it isn't called:
unregister_netdev(vport->netdev);
free_netdev(vport->netdev);
vport->netdev = NULL;
// Later in idpf_init_hard_reset(), the vport is cleared:
kfree(adapter->vports);
adapter->vports = NULL;
During an idpf HW reset, when "ethtool -g/-G" is called on the netdev,
the vport associated with the netdev is NULL, and so a kernel panic
would happen:
[ 513.185327] BUG: kernel NULL pointer dereference, address: 0000000000000038
...
[ 513.232756] RIP: 0010:idpf_get_ringparam+0x45/0x80
This can be reproduced reliably by injecting a TX timeout to cause
an idpf HW reset, and injecting a virtchnl error to cause the HW
reset to fail and retry, while calling "ethtool -g/-G" on the netdev
at the same time.If you shared the commands, how to do that, it would make reproducing the issue easier.
quoted hunk ↗ jump to hunk
With this patch applied, we see the following error but no kernel panics anymore: [ 476.323630] idpf 0000:05:00.0 eth1: failed to get ring params due to no vport in netdev Signed-off-by: Li Li <redacted> --- drivers/net/ethernet/intel/idpf/idpf_ethtool.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)diff --git a/drivers/net/ethernet/intel/idpf/idpf_ethtool.c b/drivers/net/ethernet/intel/idpf/idpf_ethtool.c index d5711be0b8e69..6a4b630b786c2 100644 --- a/drivers/net/ethernet/intel/idpf/idpf_ethtool.c +++ b/drivers/net/ethernet/intel/idpf/idpf_ethtool.c@@ -639,6 +638,10 @@ static void idpf_get_ringparam(struct net_device *netdev, idpf_vport_ctrl_lock(netdev); vport = idpf_netdev_to_vport(netdev); + if (!vport) { + netdev_err(netdev, "failed to get ring params due to no vport in netdev\n");
If vport == NULL is expected, why log it as an error. What should the user do? Wait until reset is done?
quoted hunk ↗ jump to hunk
+ goto unlock; + } ring->rx_max_pending = IDPF_MAX_RXQ_DESC; ring->tx_max_pending = IDPF_MAX_TXQ_DESC;@@ -647,6 +651,7 @@ static void idpf_get_ringparam(struct net_device *netdev, kring->tcp_data_split = idpf_vport_get_hsplit(vport); +unlock: idpf_vport_ctrl_unlock(netdev); }@@ -673,6 +674,11 @@ static int idpf_set_ringparam(struct net_device *netdev, idpf_vport_ctrl_lock(netdev); vport = idpf_netdev_to_vport(netdev); + if (!vport) { + netdev_err(netdev, "ring params not changed due to no vport in netdev\n"); + err = -EFAULT; + goto unlock_mutex; + } idx = vport->idx;
Is there another – possible more involved – solution possible to wait until the hardware reset finished? Kind regards, Paul