[1/2] igb: Teardown SR-IOV before unregister_netdev()

When the .remove() callback for a PF is called, SR-IOV support for the
device is disabled, which requires unbinding and removing the VFs.
The VFs may be in-use either by the host kernel or userspace, such as
assigned to a VM through vfio-pci.  In this latter case, the VFs may
be removed either by shutting down the VM or hot-unplugging the
devices from the VM.  Unfortunately in the case of a Windows 2012 R2
guest, hot-unplug is broken due to the ordering of the PF driver
teardown.  Disabling SR-IOV prior to unregister_netdev() avoids this
issue.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/net/ethernet/intel/igb/igb_main.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

ACK

> -----Original Message-----
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@lists.osuosl.org] On
> Behalf Of Alex Williamson
> Sent: Monday, July 27, 2015 4:19 PM
> To: intel-wired-lan@lists.osuosl.org; Kirsher, Jeffrey T
> Cc: netdev@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH 1/2] igb: Teardown SR-IOV before
> unregister_netdev()
> 
> When the .remove() callback for a PF is called, SR-IOV support for the
> device is disabled, which requires unbinding and removing the VFs.
> The VFs may be in-use either by the host kernel or userspace, such as
> assigned to a VM through vfio-pci.  In this latter case, the VFs may
> be removed either by shutting down the VM or hot-unplugging the
> devices from the VM.  Unfortunately in the case of a Windows 2012 R2
> guest, hot-unplug is broken due to the ordering of the PF driver
> teardown.  Disabling SR-IOV prior to unregister_netdev() avoids this
> issue.
> 
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> ---
>  drivers/net/ethernet/intel/igb/igb_main.c |    8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c
> b/drivers/net/ethernet/intel/igb/igb_main.c
> index 517746f..606a7ae 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -2805,14 +2805,14 @@ static void igb_remove(struct pci_dev *pdev)
>  	 */
>  	igb_release_hw_control(adapter);
> 
> -	unregister_netdev(netdev);
> -
> -	igb_clear_interrupt_scheme(adapter);
> -
>  #ifdef CONFIG_PCI_IOV
>  	igb_disable_sriov(pdev);
>  #endif
> 
> +	unregister_netdev(netdev);
> +
> +	igb_clear_interrupt_scheme(adapter);
> +
>  	pci_iounmap(pdev, hw->hw_addr);
>  	if (hw->flash_address)
>  		iounmap(hw->flash_address);
> 
> _______________________________________________
> Intel-wired-lan mailing list
> Intel-wired-lan@lists.osuosl.org
> http://lists.osuosl.org/mailman/listinfo/intel-wired-lan

> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@lists.osuosl.org] On
> Behalf Of Alex Williamson
> Sent: Monday, July 27, 2015 4:19 PM
> To: intel-wired-lan@lists.osuosl.org; Kirsher, Jeffrey T
> Cc: netdev@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH 1/2] igb: Teardown SR-IOV before
> unregister_netdev()
> 
> When the .remove() callback for a PF is called, SR-IOV support for the
> device is disabled, which requires unbinding and removing the VFs.
> The VFs may be in-use either by the host kernel or userspace, such as
> assigned to a VM through vfio-pci.  In this latter case, the VFs may
> be removed either by shutting down the VM or hot-unplugging the
> devices from the VM.  Unfortunately in the case of a Windows 2012 R2
> guest, hot-unplug is broken due to the ordering of the PF driver
> teardown.  Disabling SR-IOV prior to unregister_netdev() avoids this
> issue.
> 
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> ---
>  drivers/net/ethernet/intel/igb/igb_main.c |    8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

Tested-by: Aaron Brown <aaron.f.brown@intel.com>