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

Leon Romanovsky
2025-09-18T09:25:05Z

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
>