Bug#994166: python3-libvirt: Domain fails to start when virtio video 3D acceleration is enabled

[David Gilmour]

Package: python3-libvirt
Version: 7.0.0-2
Severity: important

Dear Maintainer,

*** Reporter, please consider answering these questions, where appropriate ***

* What led up to the situation?

qemu-system-common was upgraded to 6.1 from 5.2. This immediately broke support for 3D acceleration in a domain that had previously been using it without any problems.

The domain failed to start with the following details available in the virt-manager error popup dialog:

Error starting domain: internal error: qemu unexpectedly closed the monitor: 2021-09-13T03:51:53.214212Z qemu-system-x86_64: -device virtio-vga-gl,id=video0,max_outputs=1,bus=pcie.0,addr=0x1: missing object type 'virtio-gpu-gl-device'

Traceback (most recent call last):
File "/usr/share/virt-manager/virtManager/asyncjob.py", line 65, in cb_wrapper
callback(asyncjob, *args, **kwargs)
File "/usr/share/virt-manager/virtManager/asyncjob.py", line 101, in tmpcb
callback(*args, **kwargs)
File "/usr/share/virt-manager/virtManager/object/libvirtobject.py", line 57, in newfn
ret = fn(self, *args, **kwargs)
File "/usr/share/virt-manager/virtManager/object/domain.py", line 1329, in startup
self._backend.create()
File "/usr/lib/python3/dist-packages/libvirt.py", line 1353, in create
raise libvirtError('virDomainCreate() failed')
libvirt.libvirtError: internal error: qemu unexpectedly closed the monitor: 2021-09-13T03:51:53.214212Z qemu-system-x86_64: -device virtio-vga-gl,id=video0,max_outputs=1,bus=pcie.0,addr=0x1: missing object type 'virtio-gpu-gl-device'

The virtio-vga-gl device is new in QEMU 6.1, and is supposed to be supported by libvirt 7.6. I don't know if the problem is in the python3-libvirt package, one of the libvirt packages, or qemu.

* What exactly did you do (or not do) that was effective (or
ineffective)?

Tried to start the domain.

* What was the outcome of this action?

The domain did not start.

* What outcome did you expect instead?

I expected the domain to start.

*** End of the template - remove these template lines ***


-- System Information:
Debian Release: bookworm/sid
APT prefers testing
APT policy: (900, 'testing'), (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.10.0-8-amd64 (SMP w/8 CPU threads)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages python3-libvirt depends on:
ii libc6 2.31-17
ii libvirt0 7.6.0-1
ii python3 3.9.2-3

Versions of packages python3-libvirt recommends:
ii libvirt-daemon 7.6.0-1

python3-libvirt suggests no packages.

-- no debconf information

[Michael Tokarev]

Control: tag -1 + moreinfo

16.09.2021 18:36, David Gilmour wrote:
...
> This suggests that the qemu error is being caused by the decision to move hw-display-virtio-gpu-gl out of qemu-system-common and into qemu-system-gui.

I haven't seen this bugreport - I only received some status change
report - apparently when it has been reassigned to qemu-system-x86.

I especially moved the *new* device into -gui part since it is new
and since it has never been in use before this version. And this was
the only place left in -common which needs X11 stack, so without -gui
it can be completely "headless".

Please note qemu-system-x86 package recommends -gui part, and once
you explicitly tell apt to NOT install recommends, you accept that
you can deal with such situations and you know what you're doing.

I haven't completed a patch which suggests to install the additional
package which contains the requested functionality - when it's done
things like this will be much easier.

> Based on this, I installed the qemu-system-gui package, and the missing object error no longer appears.  However, a new error from qemu stating that
> opengl is not available appears, so installing the qemu-system-gui package is not by itself a workaround.

I don't know how to use libvirt. But a quick search for how
to enable gl with virtio-gpu reveals this:

qemu-system-x86_64 -device virtio-vga-gl -display gtk,gl=on

and this works with current debian-packaged qemu-6.1, and the
missing hw-display-virtio-gpu-gl is being opened (when -gui
part is installed).

So it seems I need some more context of how to reproduce this.

Thanks,

/mjt