Re: [PATCH v1 0/4] Fix local destination address resolution with VRF

[Leon Romanovsky <leon@kernel.org>]

On Tue, Sep 16, 2025 at 02:10:59PM +0300, Edward Srouji wrote:
> From Parav:
> 
> Presently, address resolve routines consider a destination to be local
> if the next-hop device of the resolved route for the destination is the 
> loopback netdevice. While this works for simple configurations, it fails
> when the source and destination IP addresses belong to an enslaved
> netdevice of a VRF.
> In that case the next-hop device is the VRF itself, so packets are 
> generated with an incorrect destination MAC on the VRF netdevice and 
> ib_write_bw times out.
> 
> This patch series fixes that by determining whether a destination is
> local based on the resolved route's type rather than on the next-hop
> netdevice's loopback flag.
> That approach resolves loopback traffic consistently both with and 
> without VRF configurations.
> 
> This series contains 4 patches:
>   1/4: refactor address resolution code for reuse by subsequent patches
>   2/4: resolve destination MAC via IP stack
>   3/4: use route table entry instead of netdev loopback flag
>   4/4: fix netdev lookup for IPoIB interfaces
> 
> Parav.
> 
> ---
> 
> Changelog:
> v0 -> v1:
> - Addressed comments from Leon
> - Updated commit message to reflect that dev_addr fields are invalid in
>   case of failure in PATCH 1/4
> - Removed incorrect commit log about 'no functional change' in PATCH 1/4
> 
> v0: https://lore-kernel.gnuweeb.org/lkml/20250907160833.56589-5-edwards@nvidia.com/T/
> 
> ---
> 
> Parav Pandit (3):
>   RDMA/core: Squash a single user static function
>   RDMA/core: Resolve MAC of next-hop device without ARP support
>   RDMA/core: Use route entry flag to decide on loopback traffic
> 
> Vlad Dumitrescu (1):
>   IB/ipoib: Ignore L3 master device
> 
>  drivers/infiniband/core/addr.c            | 83 +++++++++++------------
>  drivers/infiniband/ulp/ipoib/ipoib_main.c | 21 +++---
>  2 files changed, 50 insertions(+), 54 deletions(-)

I applied this series, but please never send series as reply-to. It
broke all flows: b4 automatic apply script, patchworks and "Thanks you .."
email.

Thanks

> 
> -- 
> 2.21.3
>