Re: [Qemu-devel] [PATCH v6 04/12] tests: Add vm test lib

[Philippe Mathieu-Daudé]

Hi Fam, Alex,

> > If this fails it's fairly cryptic:
> >
> > /home/alex/lsrc/qemu/qemu.git/tests/vm/openbsd  --debug   --image 
> > "tests/vm/openbsd.img" --build-qemu /home/alex/lsrc/qemu/qemu.git
> > DEBUG:root:Creating archive ./vm-test-fxejnB.tmp/data-2de24.tar for src_dir 
> > dir: /home/alex/lsrc/qemu/qemu.git
> > DEBUG:root:QEMU args: -nodefaults -m 2G -cpu host -netdev 
> > user,id=vnet,hostfwd=:0.0.0.0:0-:22 -device virtio-net-pci,netdev=vnet -vnc 
> > :0,to=20 -serial file:./vm-test-fxejnB.tmp/serial.out -smp 4 -enable-kvm 
> > -device VGA -drive 
> > file=tests/vm/openbsd.img,snapshot=on,if=none,id=drive0,cache=writeback -device 
> > virtio-blk,drive=drive0,bootindex=0 -drive 
> > file=./vm-test-fxejnB.tmp/data-2de24.tar,if=none,id=data-2de24,cache=writeback,format=raw
> >  -device virtio-blk,drive=data-2de24,serial=data-2de24,bootindex=1
> > Failed to prepare guest environment
> > Traceback (most recent call last):
> >    File "/home/alex/lsrc/qemu/qemu.git/tests/vm/basevm.py", line 260, in main
> >      vm.boot(args.image + ",snapshot=on")
> >    File "/home/alex/lsrc/qemu/qemu.git/tests/vm/basevm.py", line 184, in boot
> >      guest.launch()
> >    File "/home/alex/lsrc/qemu/qemu.git/tests/vm/../../scripts/qemu.py", line 
> > 151, in launch
> >      self._post_launch()
> >    File "/home/alex/lsrc/qemu/qemu.git/tests/vm/../../scripts/qemu.py", line 
> > 135, in _post_launch
> >      self._qmp.accept()
> >    File "/home/alex/lsrc/qemu/qemu.git/tests/vm/../../scripts/qmp/qmp.py", line 
> > 147, in accept
> >      return self.__negotiate_capabilities()
> >    File "/home/alex/lsrc/qemu/qemu.git/tests/vm/../../scripts/qmp/qmp.py", line 
> > 60, in __negotiate_capabilities
> >      raise QMPConnectError
> > QMPConnectError
> >
> > I assume QEMU failed to boot and might have given us a message that
> > would be useful.
>
> It's a separate issue of qemu.py, I didn't try to fix it here because currently
> there are many patches touching that file on the list, there is a high chance of
> conflict.
>
> In your case which qemu version are you using? If not master it probably is
> failing because of the hostfwd syntax.

very likely.

one simple way to handle this could be having this script catching 
QMPConnectError and restart with older command line format,

but I prefer starting QEMU binding a QMP socket, then initialize the 
options via QMP packets, this should be more portable, this is cleaner.

also I think we don't want to run those images with bleeding edge 
qemu-system, we want a stable QEMU to be able to compile the bleeding 
edge codebase inside a working VM.

another note: currently when a VM fails, it closes and what I've left is 
only the last stderr.
I'd rather see 2 modes:
- run from some CI when only the final return value is useful, the 
stderr being extra value.
- in user-dev mode if the build fails I'd like to have access to the 
terminal, eventually some msg like "this build failed, you can connect 
to this VM copy/pasting the following ssh command: ... or hit ^C to 
gracefully shutdown the VM"
But in this mode I'd rather mount my current workdir via a read-writable 
netshare rather than a one-time temporary read-only tarball, so I could 
modify my repo and just run 'make' inside the VM.

Regards,

Phil.