[Intel-wired-lan] [PATCH net-next v2] iavf: Fix kernel BUG in free_msi_irqs

[Jankowski, Konrad0]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces at osuosl.org> On Behalf Of
> Mateusz Palczewski
> Sent: piątek, 22 października 2021 10:30
> To: intel-wired-lan at lists.osuosl.org
> Cc: Palczewski, Mateusz <mateusz.palczewski at intel.com>; Patynowski,
> PrzemyslawX <przemyslawx.patynowski at intel.com>
> Subject: [Intel-wired-lan] [PATCH net-next v2] iavf: Fix kernel BUG in
> free_msi_irqs
> 
> From: Przemyslaw Patynowski <przemyslawx.patynowski at intel.com>
> 
> Fix driver not freeing VF's traffic irqs, prior to calling pci_disable_msix in
> iavf_remove.
> There were possible 2 erroneous states in which, iavf_close would not be
> called.
> One erroneous state is fixed by allowing netdev to register, when state is
> already running. It was possible for VF adapter to enter state loop from
> running to resetting, where iavf_open would subsequently fail.
> If user would then unload driver/remove VF pci, iavf_close would not be
> called, as the netdev was not registered, leaving traffic pcis still allocated.
> Fixed this by breaking loop, allowing netdev to open device when adapter
> state is __IAVF_RUNNING and it is not explicitily downed.
> Other possiblity is entering to iavf_remove from __IAVF_RESETTING state,
> where iavf_close would not free irqs, but just return 0.
> Fixed this by checking for last adapter state and then removing irqs.
> 
> Kernel panic:
> [ 2773.628585] kernel BUG at drivers/pci/msi.c:375!
> ...
> [ 2773.631567] RIP: 0010:free_msi_irqs+0x180/0x1b0 ...
> [ 2773.640939] Call Trace:
> [ 2773.641572]  pci_disable_msix+0xf7/0x120 [ 2773.642224]
> iavf_reset_interrupt_capability.part.41+0x15/0x30 [iavf] [ 2773.642897]
> iavf_remove+0x12e/0x500 [iavf] [ 2773.643578]
> pci_device_remove+0x3b/0xc0 [ 2773.644266]
> device_release_driver_internal+0x103/0x1f0
> [ 2773.644948]  pci_stop_bus_device+0x69/0x90 [ 2773.645576]
> pci_stop_and_remove_bus_device+0xe/0x20
> [ 2773.646215]  pci_iov_remove_virtfn+0xba/0x120 [ 2773.646862]
> sriov_disable+0x2f/0xe0 [ 2773.647531]  ice_free_vfs+0x2f8/0x350 [ice] [
> 2773.648207]  ice_sriov_configure+0x94/0x960 [ice] [ 2773.648883]  ?
> _kstrtoull+0x3b/0x90 [ 2773.649560]  sriov_numvfs_store+0x10a/0x190 [
> 2773.650249]  kernfs_fop_write+0x116/0x190 [ 2773.650948]
> vfs_write+0xa5/0x1a0 [ 2773.651651]  ksys_write+0x4f/0xb0 [ 2773.652358]
> do_syscall_64+0x5b/0x1a0 [ 2773.653075]
> entry_SYSCALL_64_after_hwframe+0x65/0xca
> 
> Fixes: 22ead37f8af8 ("i40evf: Add longer wait after remove module")
> Signed-off-by: Przemyslaw Patynowski
> <przemyslawx.patynowski at intel.com>
> Signed-off-by: Mateusz Palczewski <mateusz.palczewski at intel.com>
> ---
>  This is a fix but it needs to be targeted to net-next because this feature  is
> not present on net yet.
> ---
>  v2: Targeted to correct tree
> ---
>  drivers/net/ethernet/intel/iavf/iavf.h      | 36 +++++++++++++++++++++
>  drivers/net/ethernet/intel/iavf/iavf_main.c | 20 ++++++++++++
>  2 files changed, 56 insertions(+)
> 

Tested-by: Konrad Jankowski <konrad0.jankowski at intel.com>