Am 20.01.2018 um 21:57 schrieb Liran Alon:
>
> ----- hermann@xxxxxxx wrote:
>
>> Hi,
>> I today upgraded my KVM host from Debian 8 to the latest Debian 9
>> (Stretch). This worked perfectly, however, 2 old guest systems (SuSE
>> 9.1, kernel 2.6.7 / 2.6.5) have no network access.
>>
>> All other machines running on this host are Linux Debian machines and
>> use the "virtio" networking drivere whereas those two old machines
>> use
>> RTL8139 (or e1000, makes no difference).
>>
>> On the guest side, the networking interface (eth0 / rtl8139) is up,
>> it
>> states "Link Up / 100MBit" in the log file, everything looks fine, but
>> I
>> can't get out, no ping, empty arp table etc.
>>
>> Basically, I use bridging for the virtual hosts, this looks like
>> this:
>>
>> br0 8000.0026186273f4 no eth0
>> vnet0
>> vnet1
>>
>> or like so:
>>
>> port no mac addr is local? ageing timer
>> 1 00:00:24:cc:c7:85 no 0.42
>> 1 00:19:66:b3:cb:34 no 3.97
>> 1 00:22:b0:cf:04:b2 no 0.03
>>
>>
>> What is interesting is that I cannot find the MAC Address of the 2
>> machines in the above table, which is probably not good.
>>
>> Forwarding is enabled for all bridges and there is no packet filter /
>> firewall.
>>
>> I have no clue how to solve this problem - do you have any idea?
>>
>> Kernel version (uname -rv):
>> Linux version 4.9.0-5-amd64 (debian-kernel@xxxxxxxxxxxxxxxx) (gcc
>> version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian
>> 4.9.65-3+deb9u2
>> (2018-01-04)
>>
>> kvm --version:
>> QEMU emulator version 2.8.1(Debian 1:2.8+dfsg-6+deb9u3)
>>
>>
>> Best Regards,
>> Hermann
>>
>> --
>> hermann@xxxxxxx
>> PGP/GPG: 299893C7 (on keyservers)
>
> 1. What do you see when sniffing (with tcpdump) the QEMU's tap devices which represent the guest's NICs? Do you see any traffic there?
>
> 2. Examining the KVM events trace may also be helpful. It's very easy to extract:
> # echo 1 >/sys/kernel/debug/tracing/events/kvm/enable
> # cat /sys/kernel/debug/tracing/trace_pipe > /tmp/trace
> # echo 0 >/sys/kernel/debug/tracing/events/kvm/enable
Thanks for your quick reply.
For tcpdump, I see on the guest side ARP-requests. On the host side on
the tap device I do see traffic but from other machines, none of the
specific guest.
For the KVM events trace - any hint about how to interprete the output?
There is massive amounts of data, which look mostly like this:
CPU 0/KVM-18088 [001] .... 161817.943123: kvm_pio: pio_read at 0x40 size
1 count 1 val 0x4
CPU 0/KVM-18088 [001] d... 161817.943124: kvm_entry: vcpu 0
CPU 0/KVM-18088 [001] .... 161817.943125: kvm_exit: reason
IO_INSTRUCTION rip 0xc010feb1 info 200040 0
CPU 0/KVM-2451 [003] .... 161817.943125: kvm_exit: reason
APIC_ACCESS rip 0xffffffff84a4f8d2 info 1380 0
Is there anything I should look for? Moreover, I don't know which
virtual machine is e.g. "KVM-18088"?
Best Regards,
Hermann
--
hermann@xxxxxxx
PGP/GPG: 299893C7 (on keyservers)
