[DPDK/ethdev Bug 1971] [net/mlx5] PF initialization inside DPDK app conflicts with kernel bond on neighbouring port

[DPDK/ethdev Bug 1971] [net/mlx5] PF initialization inside DPDK app conflicts with kernel bond on neighbouring port

[bugzilla]

http://bugs.dpdk.org/show_bug.cgi?id=1971

            Bug ID: 1971
           Summary: [net/mlx5] PF initialization inside DPDK app conflicts
                    with kernel bond on neighbouring port
           Product: DPDK
           Version: 26.07
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: Normal
         Component: ethdev
          Assignee: dev@dpdk.org
          Reporter: volodia.bond@gmail.com
  Target Milestone: ---

## Overview

Seems like false positive detection of PF being a part of kernel bond and/or
wrong IBV device is assigned to DPDK ports when initialized along kernel bond.

Works with DPDK 25.03, possible regression after DPDK 26.03.

## Hardware and environment
* Debian 13 (trixie)
* 2 x ConnectX-6 Dx (MT2892 Family)
* Ethtool Info: 
```
driver: mlx5_core
version: 6.12.94+deb13-amd64
firmware-version: 22.48.1000 (MT_0000000436)
```
* DPDK: main@bcd1686caa94aed1edf9f25dd1cc51175cedd1b7 (20.07.2026)
* Kernel devices: ens6f0np0 (38.00.0), ens6f1np1 (38.00.1), ens11f0np0
(98:00.0), ens11f0np0 (98:00.1)

* Network setup (might be simplified, but dunno if vlan/LAG matters)
```
# 1 port from each ConnectX-6 is bonded, remaining ports are used by DPDK.

S (server) <-> SW <-> C (client)

1. kernel bond <-> [ens6f1np1 + ens11f1np1] <-> trunk LAG, vlan.111
2. DPDK <-> [ens6f0np0 + ens11f0np0] <-> trunk LAG, vlan.222 

C (client) should reach:
1. server bond IP via (ens6f1np1 | ens11f1np1) on vlan.111
2. [OPTIONAL] DPDK ports (ens6f0np0 | ens11f0np0) on vlan.222
```

## Steps to reproduce

1. Initilal state - testpmd is not running, no bond device present
2. Initialize bond device (IP network should match client subnet):
```
ip link del dev bond0 >/dev/null 2>&1 
ip link add bond0 type bond mode balance-rr 
ip link set ens6f1np1 down 
ip link set ens11f1np1 down 
ip link set ens6f1np1 master bond0 
ip link set ens11f1np1 master bond0 
ip link set bond0 up 
ip link add link bond0 name test.111 type vlan id 111 
ip addr add dev test.111 11.11.0.2/16 ip link set dev test.111 up
```
3. Start testpmd on non-bonded devices:
```
dpdk-testpmd --in-memory --no-telemetry -a 0000:38:00.0 -a 0000:98:00.0 -- -a
--forward-mode rxonly
```
4. Start C -> S pings via vlan.111 (targeting kernel bond)
5. Start tcpdump on bonded interfaces: 
```
tcpdump -eni ens6f1np1
tcpdump -eni ens11f1np1
```

## Expected results
Bond device is accessible, ping is working, ICMP traffic is captured by
tcpdump.

## Actual results
No pings to bond device, no ICMP packets captured.

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