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.