Created attachment 821066 [details]
soft lockup traces

simple workaround is to disable desktop effects (Alt+Shift+F12)

Seeing something very similar here: F20 Beta (RC5) installed to a KVM with the KDE package set, usually the VM hangs (as in, can't interact with anything, can't get to a VT, can't power off) shortly after I log in, and I have what looks like the same trace in my journalctl:

Nov 07 13:42:34 localhost.localdomain kernel: ------------[ cut here ]------------
Nov 07 13:42:34 localhost.localdomain kernel: kernel BUG at drivers/gpu/drm/ttm/ttm_bo.c:173!
Nov 07 13:42:35 localhost.localdomain kernel: invalid opcode: 0000 [#1] SMP 
Nov 07 13:42:35 localhost.localdomain kernel: Modules linked in: uinput nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6table_mangle ip6table_security ip6table_raw ip6t_REJECT iptable_nat nf_nat_ipv4 iptable_mangle iptable_security iptable_raw nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack bnep ebtable_filter bluetooth rfkill ebtables ip6table_filter ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 nf_nat nf_conntrack ip6_tables snd_hda_intel snd_hda_codec snd_hwdep joydev snd_seq snd_seq_device ppdev snd_pcm parport_pc parport microcode virtio_balloon serio_raw snd_page_alloc i2c_piix4 snd_timer snd soundcore mperf nfsd auth_rpcgss nfs_acl lockd sunrpc dm_crypt virtio_blk ne2k_pci 8390 qxl sym53c8xx drm_kms_helper scsi_transport_spi ttm virtio_net drm i2c_core ata_generic pata_acpi
Nov 07 13:42:35 localhost.localdomain kernel: CPU: 0 PID: 1653 Comm: X Not tainted 3.11.6-301.fc20.x86_64 #1
Nov 07 13:42:35 localhost.localdomain kernel: Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Nov 07 13:42:35 localhost.localdomain kernel: task: ffff88007b4bdb80 ti: ffff880036bb2000 task.ti: ffff880036bb2000
Nov 07 13:42:35 localhost.localdomain kernel: RIP: 0010:[<ffffffffa0084017>]  [<ffffffffa0084017>] ttm_bo_add_to_lru+0xb7/0xc0 [ttm]
Nov 07 13:42:35 localhost.localdomain kernel: RSP: 0018:ffff880036bb3cb8  EFLAGS: 00010287
Nov 07 13:42:35 localhost.localdomain kernel: RAX: ffff88003725a0e8 RBX: ffff8800048f5c48 RCX: 00000000fffffffa
Nov 07 13:42:35 localhost.localdomain kernel: RDX: 0000000000000000 RSI: 00000000000008da RDI: ffff8800048f5d00
Nov 07 13:42:35 localhost.localdomain kernel: RBP: ffff880036bb3cc0 R08: ffff88000df04b18 R09: ffff88003fd13aa0
Nov 07 13:42:35 localhost.localdomain kernel: R10: ffffffffa00c5414 R11: 0000000000000000 R12: ffff880004924c00
Nov 07 13:42:35 localhost.localdomain kernel: R13: ffff880004924c28 R14: ffff8800048f5c48 R15: ffff8800374bff00
Nov 07 13:42:35 localhost.localdomain kernel: FS:  00007fe10b4d19c0(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
Nov 07 13:42:35 localhost.localdomain kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Nov 07 13:42:35 localhost.localdomain kernel: CR2: 000000000091b7b8 CR3: 000000007a613000 CR4: 00000000000006f0
Nov 07 13:42:35 localhost.localdomain kernel: Stack:
Nov 07 13:42:35 localhost.localdomain kernel:  ffff880004924e00 ffff880036bb3d00 ffffffffa00c59f1 ffff88003725a0e8
Nov 07 13:42:35 localhost.localdomain kernel:  0000000000000004 ffff88005eb1f840 ffff88003725a000 0000000000000004
Nov 07 13:42:35 localhost.localdomain kernel:  ffff88005eb1f8b8 ffff880036bb3db8 ffffffffa00c5079 ffff880036bb3fd8
Nov 07 13:42:35 localhost.localdomain kernel: Call Trace:
Nov 07 13:42:35 localhost.localdomain kernel:  [<ffffffffa00c59f1>] qxl_release_fence_buffer_objects+0x81/0xe4 [qxl]
Nov 07 13:42:35 localhost.localdomain kernel:  [<ffffffffa00c5079>] qxl_execbuffer_ioctl+0x6d9/0x720 [qxl]
Nov 07 13:42:35 localhost.localdomain kernel:  [<ffffffffa0024142>] drm_ioctl+0x532/0x660 [drm]
Nov 07 13:42:35 localhost.localdomain kernel:  [<ffffffff8116da05>] ? do_mmap_pgoff+0x305/0x3c0
Nov 07 13:42:35 localhost.localdomain kernel:  [<ffffffff811b9e1d>] do_vfs_ioctl+0x2dd/0x4b0
Nov 07 13:42:35 localhost.localdomain kernel:  [<ffffffff811ba071>] SyS_ioctl+0x81/0xa0
Nov 07 13:42:35 localhost.localdomain kernel:  [<ffffffff81657b19>] system_call_fastpath+0x16/0x1b
Nov 07 13:42:35 localhost.localdomain kernel: Code: e1 b8 01 00 00 00 f0 0f c1 43 3c 83 c0 01 83 f8 01 7e 03 5b 5d c3 e8 79 84 00 00 eb f6 0f 1f 80 00 00 00 00 e8 6b 84 00 00 eb af <0f> 0b 0f 1f 80 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 45 
Nov 07 13:42:35 localhost.localdomain kernel: RIP  [<ffffffffa0084017>] ttm_bo_add_to_lru+0xb7/0xc0 [ttm]
Nov 07 13:42:35 localhost.localdomain kernel:  RSP <ffff880036bb3cb8>
Nov 07 13:42:35 localhost.localdomain kernel: ---[ end trace d618605758b302a4 ]---
Nov 07 13:42:35 localhost.localdomain abrt-server[3408]: Looking for kernel package
Nov 07 13:42:36 localhost.localdomain abrt-server[3408]: Kernel package kernel-3.11.6-301.fc20.x86_64 found
Nov 07 13:42:36 localhost.localdomain abrt-dump-oops[3407]: Reported 1 kernel oopses to Abrt

Proposing as a Final blocker as a conditional violation of both Beta virtualization criteria - https://fedoraproject.org/wiki/Fedora_20_Beta_Release_Criteria#Virtualization_requirements - in the case where you install KDE to a standard (qxl/SPICE) KVM. I guess using cirrus may well work around this too.

xorg-x11-drv-qxl-0.1.1-2.fc20 has been submitted as an update for Fedora 20.
https://admin.fedoraproject.org/updates/xorg-x11-drv-qxl-0.1.1-2.fc20

Package xorg-x11-drv-qxl-0.1.1-2.fc20:
* should fix your issue,
* was pushed to the Fedora 20 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing xorg-x11-drv-qxl-0.1.1-2.fc20'
as soon as you are able to.
Please go to the following url:
https://admin.fedoraproject.org/updates/FEDORA-2013-20951/xorg-x11-drv-qxl-0.1.1-2.fc20
then log in and leave karma (feedback).

Someone in the KDE Test Day reported kwin crashing in a VM with this segfault:

 This is what I get from the crash logs:

Application: KWin (kwin), signal: Segmentation fault
Using host libthread_db library "/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0xb16417c0 (LWP 1539))]

Thread 4 (Thread 0xae1b1b40 (LWP 1542)):
#0  0xb77bc424 in __kernel_vsyscall ()
#1  0xb61097ac in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb7112c02 in QTWTF::TCMalloc_PageHeap::scavengerThread() () from /lib/libQtScript.so.4
#3  0xb7112c50 in QTWTF::TCMalloc_PageHeap::runScavengerThread(void*) () from /lib/libQtScript.so.4
#4  0xb6105d8a in start_thread () from /lib/libpthread.so.0
#5  0xb531d9be in clone () from /lib/libc.so.6

Thread 3 (Thread 0xaef84b40 (LWP 1592)):
#0  0xb77bc424 in __kernel_vsyscall ()
#1  0xb6109b76 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb6182863 in QWaitCondition::wait(QMutex*, unsigned long) () from /lib/libQtCore.so.4
#3  0xb6174b6e in QThreadPoolThread::run() () from /lib/libQtCore.so.4
#4  0xb61822bb in QThreadPrivate::start(void*) () from /lib/libQtCore.so.4
#5  0xb6105d8a in start_thread () from /lib/libpthread.so.0
#6  0xb531d9be in clone () from /lib/libc.so.6

Thread 2 (Thread 0xac520b40 (LWP 1628)):
#0  0xb77bc424 in __kernel_vsyscall ()
#1  0xb610ce46 in nanosleep () from /lib/libpthread.so.0
#2  0xae2fbc44 in RTThreadSleep () from /usr/lib/dri/vboxvideo_dri.so
#3  0xae2c2402 in ?? () from /usr/lib/dri/vboxvideo_dri.so
#4  0xae2fd6a0 in rtThreadMain () from /usr/lib/dri/vboxvideo_dri.so
#5  0xae308bb6 in ?? () from /usr/lib/dri/vboxvideo_dri.so
#6  0xb6105d8a in start_thread () from /lib/libpthread.so.0
#7  0xb531d9be in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb16417c0 (LWP 1539)):
[KCrash Handler]
#6  0xad54cca7 in packspu_TexImage2D () from /lib/VBoxOGLpackspu.so
#7  0xae2f6493 in cr_glTexImage2D () from /usr/lib/dri/vboxvideo_dri.so
#8  0xb5581866 in glTexImage2D () from /lib/libGL.so.1
#9  0xb6bf18f2 in KWin::GLTexture::GLTexture(int, int) () from /lib/libkwinglutils.so.1
#10 0xad3d42e0 in KWin::BlurEffect::BlurEffect() () from /usr/lib/kde4/kwin4_effect_builtins.so
#11 0xad3d45f7 in effect_create_kwin4_effect_blur () from /usr/lib/kde4/kwin4_effect_builtins.so
#12 0xb76cebc7 in KWin::EffectsHandlerImpl::loadEffect(QString const&, bool) () from /lib/libkdeinit4_kwin.so
#13 0xb76cf706 in KWin::EffectsHandlerImpl::slotEffectsQueried() () from /lib/libkdeinit4_kwin.so
#14 0xb760d970 in KWin::EffectsHandlerImpl::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) [clone .part.21] () from /lib/libkdeinit4_kwin.so
#15 0xb62b31d5 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /lib/libQtCore.so.4
#16 0xb63032e6 in QFutureWatcherBase::finished() () from /lib/libQtCore.so.4
#17 0xb617122c in QFutureWatcherBasePrivate::sendCallOutEvent(QFutureCallOutEvent*) () from /lib/libQtCore.so.4
#18 0xb617150c in QFutureWatcherBase::event(QEvent*) () from /lib/libQtCore.so.4
#19 0xb5743a94 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib/libQtGui.so.4
#20 0xb574a9ec in QApplication::notify(QObject*, QEvent*) () from /lib/libQtGui.so.4
#21 0xb6958b70 in KApplication::notify(QObject*, QEvent*) () from /lib/libkdeui.so.5
#22 0xb76449ea in KWin::Application::notify(QObject*, QEvent*) () from /lib/libkdeinit4_kwin.so
#23 0xb629d516 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib/libQtCore.so.4
#24 0xb62a098a in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /lib/libQtCore.so.4
#25 0xb62a0e8d in QCoreApplication::sendPostedEvents(QObject*, int) () from /lib/libQtCore.so.4
#26 0xb57faaca in QEventDispatcherX11::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/libQtGui.so.4
#27 0xb629be50 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/libQtCore.so.4
#28 0xb629c1e1 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/libQtCore.so.4
#29 0xb62a1e9b in QCoreApplication::exec() () from /lib/libQtCore.so.4
#30 0xb5741da5 in QApplication::exec() () from /lib/libQtGui.so.4
#31 0xb7645dac in kdemain () from /lib/libkdeinit4_kwin.so
#32 0x0804884c in main ()

would that probably be caused by this bug, or something different? The image they were using would have had the affected qxl.

nope that doesn't look the same, I'd go with something different.

xorg-x11-drv-modesetting-0.8.0-3.fc19 has been submitted as an update for Fedora 19.
https://admin.fedoraproject.org/updates/xorg-x11-drv-modesetting-0.8.0-3.fc19

xorg-x11-drv-qxl-0.1.1-2.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

xorg-x11-drv-modesetting-0.8.0-3.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Quite nasty problem related to memory management and reference counting. Patch at http://lists.freedesktop.org/archives/spice-devel/2015-May/019962.html.

To easy reproduce the issue enable KMS and composite in xorg-x11-drv-qxl package (remove no-surfaces-kms.patch and qxl-kms-disable-composite.patch patches), install KDE and open some OpenOffice applications (I used Draw and Presentation) which use a lot of objects, continue opening and close these applications for a while, minimizing and maximizing them and after a while you will see a lot of problems in dmesg and on screen (unless it freezes).

is there a reason you re-opened this bug instead of filing a new one? there was clearly an update issued specifically to fix the bug that was initially reported here back in 2013...

I though was the right way as the problem is the same.

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