Re: [PATCH 0/5] net/failsafe: fixes for sub-device removal and configuration

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 14 Oct 2026 19:42:52 +0000
Sandeep Penigalapati <sandeep.penigalapati@intel.com> wrote:

> This series collects fixes for the fail-safe PMD found while testing
> live migration of a VF-backed sub-device (iavf) paired with a virtio-net
> standby sub-device.
> 
> - double release of the sub-device port on hot-unplug;
> - NULL queue-release op on sub-devices that do not implement it;
> - MAC address pool size off-by-one and replay of zeroed MAC slots;
> - unsupported link-status control (-ENOTSUP) treated as fatal;
> - sub-device removal not detected without the RMV interrupt (e.g. VFIO
>   device release), now handled through a bus device-event callback.
> 
> 
> Sandeep Penigalapati (5):
>   net/failsafe: fix double release of sub-device port
>   net/failsafe: fix queue release without sub-device op
>   net/failsafe: fix MAC address pool size and replay
>   net/failsafe: ignore unsupported link status update
>   net/failsafe: detect sub-device removal via device event
> 
>  drivers/net/failsafe/failsafe_ether.c   | 40 ++++++++++--
>  drivers/net/failsafe/failsafe_ops.c     | 24 ++++++-
>  drivers/net/failsafe/failsafe_private.h | 13 ++--
>  drivers/net/failsafe/failsafe_rxtx.c    | 83 +------------------------
>  4 files changed, 62 insertions(+), 98 deletions(-)
> 

One related failsafe issue is that today tap is carrying some stubs
only because failsafe doesn't handle ENOTSUP