[REGRESSION] Networking for Firefox broken on second VM run

[REGRESSION] Networking for Firefox broken on second VM run

[Alyssa Ross]

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Since we introduced the userspace router, if I start the Firefox VM,
quit Firefox, wait for the VM to shut down, and then start it again,
networking no longer works, and I see repeating log lines like this:

2025-12-09 09:13:29.147240893  [2025-12-09T09:13:29Z WARN  spectrum_router::router] interface App(0) has been blocked for 1 sec, dropping packet

Full reproduction steps:

1. cd host/rootfs
2. nix-shell --run 'make clean && make run'
3. Start Firefox VM with vm-start
4. See that networking works
5. Quit Firefox and wait a few seconds for VM to stop
6. Start Firefox VM with vm-start again
7. No more networking, and log lines like the above

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Re: [REGRESSION] Networking for Firefox broken on second VM run

[Alyssa Ross]

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Alyssa Ross <hi@alyssa.is> writes:

> Since we introduced the userspace router, if I start the Firefox VM,
> quit Firefox, wait for the VM to shut down, and then start it again,
> networking no longer works, and I see repeating log lines like this:
>
> 2025-12-09 09:13:29.147240893  [2025-12-09T09:13:29Z WARN  spectrum_router::router] interface App(0) has been blocked for 1 sec, dropping packet

Ah, and there's also this just as the first Firefox VM exits:

2025-12-09 09:51:17.380783524  [2025-12-09T09:51:17Z ERROR virtio_queue::queue] Iterator error trying to process requests on a queue that's not ready
2025-12-09 09:51:17.380846889  [2025-12-09T09:51:17Z ERROR virtio_queue::queue] Iterator error trying to process requests on a queue that's not ready

> Full reproduction steps:
>
> 1. cd host/rootfs
> 2. nix-shell --run 'make clean && make run'
> 3. Start Firefox VM with vm-start
> 4. See that networking works
> 5. Quit Firefox and wait a few seconds for VM to stop
> 6. Start Firefox VM with vm-start again
> 7. No more networking, and log lines like the above

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Re: [REGRESSION] Networking for Firefox broken on second VM run

[Alyssa Ross]

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Alyssa Ross <hi@alyssa.is> writes:

> Alyssa Ross <hi@alyssa.is> writes:
>
>> Since we introduced the userspace router, if I start the Firefox VM,
>> quit Firefox, wait for the VM to shut down, and then start it again,
>> networking no longer works, and I see repeating log lines like this:
>>
>> 2025-12-09 09:13:29.147240893  [2025-12-09T09:13:29Z WARN  spectrum_router::router] interface App(0) has been blocked for 1 sec, dropping packet
>
> Ah, and there's also this just as the first Firefox VM exits:
>
> 2025-12-09 09:51:17.380783524  [2025-12-09T09:51:17Z ERROR virtio_queue::queue] Iterator error trying to process requests on a queue that's not ready
> 2025-12-09 09:51:17.380846889  [2025-12-09T09:51:17Z ERROR virtio_queue::queue] Iterator error trying to process requests on a queue that's not ready

And repeated stuff like this from the guest kernel:

[  402.381203] virtio_net virtio2 eth1: NETDEV WATCHDOG: CPU: 0: transmit queue 0 timed out 5792 ms
[  402.382150] virtio_net virtio2 eth1: TX timeout on queue: 0, sq: output.0, vq: 0x1, name: output.0, 5792000 usecs ago

>> Full reproduction steps:
>>
>> 1. cd host/rootfs
>> 2. nix-shell --run 'make clean && make run'
>> 3. Start Firefox VM with vm-start
>> 4. See that networking works
>> 5. Quit Firefox and wait a few seconds for VM to stop
>> 6. Start Firefox VM with vm-start again
>> 7. No more networking, and log lines like the above

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