Re: iotest 040, 041, intermittent failure in netbsd VM

[Li Zhang <lizhang@suse.de>]

On 1/18/22 12:08 AM, John Snow wrote:
> On Mon, Jan 17, 2022 at 3:49 PM Peter Maydell <peter.maydell@linaro.org> wrote:
>>
>> On Mon, 17 Jan 2022 at 20:35, John Snow <jsnow@redhat.com> wrote:
>>
>>> Can you please try applying this temporary patch and running `./check
>>> -qcow2 040 041` until you see a breakage and show me the output from
>>> that?
>>
>> With this temporary patch the VM doesn't launch at all:
> 
> "Works for me", but I found out why.
> 
>>
>> peter.maydell@hackbox2.linaro.org:~/qemu-netbsd$ make -C build/
>> vm-build-netbsd J=8 V=1 2>&1 | tee netbsd.log
>> make: Entering directory '/home/peter.maydell/qemu-netbsd/build'
>> /usr/bin/python3 -B /home/peter.maydell/qemu-netbsd/meson/meson.py
>> introspect --targets --tests --benchmarks | /usr/bin/python3 -B
>> scripts/mtest2m
>> ake.py > Makefile.mtest
>> { \
>>    echo 'ninja-targets = \'; \
>>    /usr/bin/ninja -t targets all | sed 's/:.*//; $!s/$/ \\/'; \
>>    echo 'build-files = \'; \
>>    /usr/bin/ninja -t query build.ninja | sed -n '1,/^  input:/d; /^
>> outputs:/q; s/$/ \\/p'; \
>> } > Makefile.ninja.tmp && mv Makefile.ninja.tmp Makefile.ninja
>> (GIT="git" "/home/peter.maydell/qemu-netbsd/scripts/git-submodule.sh"
>> update ui/keycodemapdb meson tests/fp/berkeley-testfloat-3
>> tests/fp/berkeley-softfloat-3 dtc capstone slirp)
>> (GIT="git" "/home/peter.maydell/qemu-netbsd/scripts/git-submodule.sh"
>> update ui/keycodemapdb meson tests/fp/berkeley-testfloat-3
>> tests/fp/berkeley-softfloat-3 dtc capstone slirp)
>> /usr/bin/python3 -B /home/peter.maydell/qemu-netbsd/tests/vm/netbsd
>> --debug  --jobs 8 --verbose    --image
>> "/home/peter.maydell/.cache/qemu-vm/images/netbsd.img"  --snapshot
>> --build-qemu /home/peter.maydell/qemu-netbsd --
>> DEBUG:root:Creating archive
>> /home/peter.maydell/qemu-netbsd/build/vm-test-72ra6_8s.tmp/data-f706c.tar
>> for src_dir dir: /home/peter.maydell/qemu-netbsd
>> DEBUG:root:QEMU args: -nodefaults -m 4G -cpu max -netdev
>> user,id=vnet,hostfwd=:127.0.0.1:0-:22,ipv6=no -device
>> virtio-net-pci,netdev=vnet -vnc 127.0.0.1:0,to=20 -smp 8 -enable-kvm
>> -drive file=/home/peter.maydell/.cache/qemu-vm/images/netbsd.img,snapshot=on,if=none,id=drive0,cache=writeback
>> -device virtio-blk,drive=drive0,bootindex=0 -drive
>> file=/home/peter.maydell/qemu-netbsd/build/vm-test-72ra6_8s.tmp/data-f706c.tar,if=none,id=data-f706c,cache=writeback,format=raw
>> -device virtio-blk,drive=data-f706c,serial=data-f706c,bootindex=1
>> DEBUG:asyncio:Using selector: EpollSelector
>> DEBUG:qemu.aqmp.qmp_client.qemu-2335-7f3b78d7f128:Registering
>> <qemu.aqmp.events.EventListener object at 0x7f3b76bfc9b0>.
>> DEBUG:qemu.machine.machine:VM launch command: 'qemu-system-x86_64
>> -display none -vga none -chardev
>> socket,id=mon,path=/var/tmp/qemu-machine-0m15ou19/qemu-2335-7f3b78d7f128-monitor.sock
>> -mon chardev=mon,mode=control -machine pc -chardev
>> socket,id=console,path=/var/tmp/qemu-machine-0m15ou19/qemu-2335-7f3b78d7f128-console.sock,server=on,wait=off
>> -serial chardev:console -nodefaults -m 4G -cpu max -netdev
>> user,id=vnet,hostfwd=:127.0.0.1:0-:22,ipv6=no -device
>> virtio-net-pci,netdev=vnet -vnc 127.0.0.1:0,to=20 -smp 8 -enable-kvm
>> -drive file=/home/peter.maydell/.cache/qemu-vm/images/netbsd.img,snapshot=on,if=none,id=drive0,cache=writeback
>> -device virtio-blk,drive=drive0,bootindex=0 -drive
>> file=/home/peter.maydell/qemu-netbsd/build/vm-test-72ra6_8s.tmp/data-f706c.tar,if=none,id=data-f706c,cache=writeback,format=raw
>> -device virtio-blk,drive=data-f706c,serial=data-f706c,bootindex=1'
>> DEBUG:qemu.aqmp.qmp_client.qemu-2335-7f3b78d7f128:Transitioning from
>> 'Runstate.IDLE' to 'Runstate.CONNECTING'.
>> DEBUG:qemu.aqmp.qmp_client.qemu-2335-7f3b78d7f128:Awaiting connection
>> on /var/tmp/qemu-machine-0m15ou19/qemu-2335-7f3b78d7f128-monitor.sock
>> ...
>> DEBUG:qemu.aqmp.qmp_client.qemu-2335-7f3b78d7f128:Connection accepted.
>> DEBUG:qemu.aqmp.qmp_client.qemu-2335-7f3b78d7f128:Awaiting greeting ...
>> DEBUG:qemu.aqmp.qmp_client.qemu-2335-7f3b78d7f128:<-- {
>>    "QMP": {
>>      "version": {
>>        "qemu": {
>>          "micro": 1,
>>          "minor": 11,
>>          "major": 2
>>        },
>>        "package": "(Debian 1:2.11+dfsg-1ubuntu7.38)"
>>      },
>>      "capabilities": []
>>    }
>> }
> 
> Well, today I learned that:
> 
> (1) vm-build-XXX targets use your host system's QEMU to run that VM
> (2) my QMP library cannot talk to QEMU 2.11.
> 
> That doesn't explain the intermittent netbsd failure yet, though.
> (I guess this wasn't a failure point for you due to the aggressive
> caching of the VM images? Unlucky.)
> 
> Here's another hotfix, this one I cannot easily test quickly (I don't
> have 2.11 handy and it no longer builds for me),
> but I think it'll fix the VM installation problem against older QEMU versions:
> 
> diff --git a/python/qemu/aqmp/qmp_client.py b/python/qemu/aqmp/qmp_client.py
> index 8105e29fa8..6b43e1dbbe 100644
> --- a/python/qemu/aqmp/qmp_client.py
> +++ b/python/qemu/aqmp/qmp_client.py
> @@ -292,9 +292,9 @@ async def _negotiate(self) -> None:
>           """
>           self.logger.debug("Negotiating capabilities ...")
> 
> -        arguments: Dict[str, List[str]] = {'enable': []}
> +        arguments: Dict[str, List[str]] = {}
>           if self._greeting and 'oob' in self._greeting.QMP.capabilities:
> -            arguments['enable'].append('oob')
> +            arguments.setdefault('enable', []).append('oob')
>           msg = self.make_execute_msg('qmp_capabilities', arguments=arguments)
> 
>           # It's not safe to use execute() here, because the reader/writers
> 

I also found that iotest 040, 041 fail sometimes (not always) on X86
when I run the test cases in my environment.

>