Re: [Qemu-devel] kvm: virtio-net: saved image requires TUN_F_UFO support

[Stefan Priebe - Profihost AG]

Hi Paolo,

Am 06.11.2017 um 10:49 schrieb Paolo Bonzini:
> On 06/11/2017 10:48, Stefan Priebe - Profihost AG wrote:
>> Hi Paolo,
>>
>> Am 06.11.2017 um 10:40 schrieb Paolo Bonzini:
>>> On 06/11/2017 10:38, Stefan Priebe - Profihost AG wrote:
>>>> Hello,
>>>>
>>>> i've upgraded some servers from kernel 4.4 to 4.12 - both running Qemu
>>>> 2.9.1.
>>>>
>>>> If i migrate a VM from a host running kernel 4.4 to a host running 4.12
>>>> i get:
>>>>
>>>> kvm: virtio-net: saved image requires TUN_F_UFO support
>>>> kvm: Failed to load virtio-net-device:tmp
>>>> kvm: Failed to load virtio-net:virtio
>>>> kvm: error while loading state for instance 0x0 of device
>>>> '0000:00:12.0/virtio-net'
>>>> kvm: load of migration failed: Invalid argument
>>>>
>>>>
>>>> while migrating from 4.12 to 4.4 works fine.
>>>>
>>>> Can anybody help? Is this expected?
>>>
>>> Can you check why peer_has_ufo failed (in hw/net/virtio-net.c)?
>>
>> May be - how can i archieve this? Patching the code is not a problem if
>> you can give me a hint.
>>
>>> Also, did this ioctl fail when the tap device was set up on the 4.12 
>>> destination?
>>> int tap_probe_has_ufo(int fd)
>>> {
>>>     unsigned offload;
>>>
>>>     offload = TUN_F_CSUM | TUN_F_UFO;
>>>
>>>     if (ioctl(fd, TUNSETOFFLOAD, offload) < 0)
>>>         return 0;
>>>
>>>     return 1;
>>> }
>>
>> Should there be any kernel output or how can i detect / check it?
> 
> For both, the simplest answer is probably just using printf.

arg i missed an important part. The kernel is an opensuse SLE15 one.

I've seen it contains the following patchset:
https://www.spinics.net/lists/netdev/msg443821.html

Greets,
Stefan