Re: [PATCH v3 0/2] tcp: unify IPv4 and IPv6 tap queues

[Stefano Brivio <sbrivio@redhat.com>]

On Thu, 19 Sep 2024 14:44:07 -0400
Jon Maloy <jmaloy@redhat.com> wrote:

> This should save us some memory and code.
> 
> ---
> v2: - Setting pointers to pre-set IP and MAC headers on the fly
>       instead of copying them.
>     - Merged patch #2 and #3 from v1
> v3: - Changes based on feedback from team

Sorry for the delay, now tests go a bit further but I have a similar
problem as I had on v2: guest to host, IPv6, with 65520 bytes MTU only
(perf/passt_tcp case), the iperf3 server fails to receive results, test
suite output:

=== perf/passt_tcp
> passt: throughput and latency
Throughput in Gbps, latency in µs, 4 threads at 3.6 GHz
                                        MTU: |  256B  |  576B  |  1280B |  1500B |  9000B | 65520B |
                                             |--------|--------|--------|--------|--------|--------|
   TCP throughput over IPv6: guest to host   |      - |      - |    5.8 |    6.5 |   18.1 |

and matching iperf3 server output:

- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  6]   0.00-1.01   sec   568 MBytes  4.74 Gbits/sec                  receiver
[  9]   0.00-1.01   sec   621 MBytes  5.18 Gbits/sec                  receiver
[ 11]   0.00-1.01   sec   569 MBytes  4.75 Gbits/sec                  receiver
[ 13]   0.00-1.01   sec   675 MBytes  5.63 Gbits/sec                  receiver
[SUM]   0.00-1.01   sec  2.38 GBytes  20.3 Gbits/sec                  receiver
iperf3: error - unable to receive results: Bad file descriptor

after that, connectivity from the guest seems to be pretty much gone.
I didn't debug further.

-- 
Stefano