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

Edward Srouji
2025-09-07T16:10:24Z

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.

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(-)

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2.21.3