Re: Linux 4.14 - regression: broken tun/tap / bridge network with virtio - bisected

[Jason Wang <jasowang@redhat.com>]

On 2017年12月05日 00:28, Andreas Hartmann wrote:
> On 12/03/2017 at 12:35 PM Andreas Hartmann wrote:
>> On 12/01/2017 at 11:11 AM Andreas Hartmann wrote:
>>> Hello!
>>>
>>> I hopefully could get rid of both of my problems (hanging network w/
>>> virtio) and endless hanging qemu-process on VM shutdown by upgrading
>>> qemu from 2.6.2 to 2.10.1. I hope it will persist.
>> It didn't persist. 10h later - same problems happened again. It's just
>> much harder to trigger the problems.
>>
>> I'm now trying it with
>>
>> CONFIG_RCU_NOCB_CPU=y and
>> rcu_nocbs=0-15
>>
>> Since then, I didn't see any problem any more. But this doesn't mean
>> anything until now ... .
> Didn't work ether. Disabling vhost_net's zcopy hadn't any effect, too.
>
> => It's just finally broken since
>
> 2ddf71e23cc246e95af72a6deed67b4a50a7b81c
> net: add notifier hooks for devmap bpf map

Hi:

Did you use XDP devmap in host? If not, please double check it was the 
first bad commit since the patch should only work when XDP/devmap is 
used on host.

Thanks

>
> Here is the same problem:
> https://bugzilla.kernel.org/show_bug.cgi?id=197861
>
> Any idea how to proceed?
>
>
> Thanks,
> Andreas