srange crash in virtio-gpu

srange crash in virtio-gpu

[Christian Borntraeger]

Gerd,

with current master build via a slightly fixed up fedora spec file I do get a crash in virtio-gpu
when libvirt queries the qemu. 
I can trigger that also via command line

$ /usr/bin/qemu-system-s390x -device virtio-gpu-pci,help
qemu-system-s390x: -device virtio-gpu-pci,help: missing object type 'virtio-gpu-device'
Aborted (core dumped)
$ /usr/bin/qemu-system-s390x -device virtio-gpu-ccw,help
qemu-system-s390x: -device virtio-gpu-ccw,help: missing object type 'virtio-gpu-device'
Aborted (core dumped)

Since I cannot reproduce the same when I build it without the spec file this must
be something configuration specific.
The call trace is:

(gdb) bt
#0  0x000003ff9e349026 in raise () at /lib64/libc.so.6
#1  0x000003ff9e32b162 in abort () at /lib64/libc.so.6
#2  0x000002aa274abfca in object_initialize (data=<optimized out>, size=<optimized out>, typename=0x2aa2754904e "virtio-gpu-device") at ../qom/object.c:531
#3  object_initialize (data=<optimized out>, size=<optimized out>, typename=0x2aa2754904e "virtio-gpu-device") at ../qom/object.c:519
#4  0x000002aa274ad72a in object_initialize_child_with_propsv
    (parentobj=parentobj@entry=0x2aa2801bc00, propname=propname@entry=0x2aa275d99e8 "virtio-backend", childobj=childobj@entry=0x2aa2801cd88, size=<optimized out>, type=type@entry=0x2aa2754904e "virtio-gpu-device", errp=0x2aa277f8e88 <error_abort>, vargs=0x3fff607daa0) at ../qom/object.c:564
#5  0x000002aa274ad81c in object_initialize_child_with_props
    (parentobj=parentobj@entry=0x2aa2801bc00, propname=propname@entry=0x2aa275d99e8 "virtio-backend", childobj=childobj@entry=0x2aa2801cd88, size=<optimized out>, type=type@entry=0x2aa2754904e "virtio-gpu-device", errp=0x2aa277f8e88 <error_abort>) at ../qom/object.c:547
#6  0x000002aa273718d2 in virtio_instance_init_common (proxy_obj=0x2aa2801bc00, data=0x2aa2801cd88, vdev_size=<optimized out>, vdev_name=0x2aa2754904e "virtio-gpu-device") at ../hw/virtio/virtio.c:3234
#7  0x000002aa274abea2 in object_initialize_with_type (obj=0x2aa2801bc00, size=<optimized out>, type=0x2aa27ff7240) at ../qom/object.c:515
#8  0x000002aa274ac034 in object_new_with_type (type=0x2aa27ff7240) at ../qom/object.c:729
#9  0x000002aa274b8ec0 in qmp_device_list_properties (typename=typename@entry=0x2aa280184b0 "virtio-gpu-ccw", errp=errp@entry=0x3fff607de78) at ../qom/qom-qmp-cmds.c:153
#10 0x000002aa27293362 in qdev_device_help (opts=0x2aa280184d0) at ../qdev-monitor.c:283
#11 0x000002aa2752b31e in qemu_opts_foreach (list=<optimized out>, func=func@entry=0x2aa2731f700 <device_help_func>, opaque=opaque@entry=0x0, errp=errp@entry=0x0) at ../util/qemu-option.c:1172
#12 0x000002aa27321f5c in qemu_init (argc=<optimized out>, argv=0x3fff607e418, envp=<optimized out>) at ../softmmu/vl.c:3825
#13 0x000002aa271ed042 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at ../softmmu/main.c:49


any quick idea?

Re: srange crash in virtio-gpu

[Daniel P. Berrangé]

On Thu, Sep 24, 2020 at 12:35:06PM +0200, Christian Borntraeger wrote:
> Gerd,
> 
> with current master build via a slightly fixed up fedora spec file I do get a crash in virtio-gpu
> when libvirt queries the qemu. 
> I can trigger that also via command line
> 
> $ /usr/bin/qemu-system-s390x -device virtio-gpu-pci,help
> qemu-system-s390x: -device virtio-gpu-pci,help: missing object type 'virtio-gpu-device'
> Aborted (core dumped)
> $ /usr/bin/qemu-system-s390x -device virtio-gpu-ccw,help
> qemu-system-s390x: -device virtio-gpu-ccw,help: missing object type 'virtio-gpu-device'
> Aborted (core dumped)
> 
> Since I cannot reproduce the same when I build it without the spec file this must
> be something configuration specific.

The Fedora spec builds using  --enable-modules, and the error message
shows that you don't have the .so for virtio-gpu on disk.

> The call trace is:
> 
> (gdb) bt
> #0  0x000003ff9e349026 in raise () at /lib64/libc.so.6
> #1  0x000003ff9e32b162 in abort () at /lib64/libc.so.6
> #2  0x000002aa274abfca in object_initialize (data=<optimized out>, size=<optimized out>, typename=0x2aa2754904e "virtio-gpu-device") at ../qom/object.c:531

This abort is evil though

We need this to get into the "Device '<blah>' not found"  code path
to report a nice error.


Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|

Re: srange crash in virtio-gpu

[Christian Borntraeger]

On 24.09.20 12:48, Daniel P. Berrangé wrote:
> On Thu, Sep 24, 2020 at 12:35:06PM +0200, Christian Borntraeger wrote:
>> Gerd,
>>
>> with current master build via a slightly fixed up fedora spec file I do get a crash in virtio-gpu
>> when libvirt queries the qemu. 
>> I can trigger that also via command line
>>
>> $ /usr/bin/qemu-system-s390x -device virtio-gpu-pci,help
>> qemu-system-s390x: -device virtio-gpu-pci,help: missing object type 'virtio-gpu-device'
>> Aborted (core dumped)
>> $ /usr/bin/qemu-system-s390x -device virtio-gpu-ccw,help
>> qemu-system-s390x: -device virtio-gpu-ccw,help: missing object type 'virtio-gpu-device'
>> Aborted (core dumped)
>>
>> Since I cannot reproduce the same when I build it without the spec file this must
>> be something configuration specific.
> 
> The Fedora spec builds using  --enable-modules, and the error message
> shows that you don't have the .so for virtio-gpu on disk.

Yes, I needed to include  hw-display-virtio-gpu.so as well.  Thanks.


> 
>> The call trace is:
>>
>> (gdb) bt
>> #0  0x000003ff9e349026 in raise () at /lib64/libc.so.6
>> #1  0x000003ff9e32b162 in abort () at /lib64/libc.so.6
>> #2  0x000002aa274abfca in object_initialize (data=<optimized out>, size=<optimized out>, typename=0x2aa2754904e "virtio-gpu-device") at ../qom/object.c:531
> 
> This abort is evil though
> 
> We need this to get into the "Device '<blah>' not found"  code path
> to report a nice error.

Yes, a less catastrophic way would be good.