I'm unsure where to look... Search was not successful and Logfiles are not stating any errors.

 

Any VM I've created (using standard values) does not boot beyond the BIOS screen with the assigned memory.

 

Any ideas where I can look for the root cause?

 

Example Log file (Non showed an error line):

 

2017-01-01 18:09:31.709+0000: starting up libvirt version: 1.3.1, qemu version: 2.5.1, hostname: FatMax
LC_ALL=C PATH=/bin:/sbin:/usr/bin:/usr/sbin HOME=/ QEMU_AUDIO_DRV=none /usr/local/sbin/qemu -name Ubuntu -S -machine pc-q35-2.5,accel=kvm,usb=off,mem-merge=off -drive file=/usr/share/qemu/ovmf-x64/OVMF_CODE-pure-efi.fd,if=pflash,format=raw,unit=0,readonly=on -drive file=/etc/libvirt/qemu/nvram/ddce4f00-e106-6864-3579-589b9ff61b8c_VARS-pure-efi.fd,if=pflash,format=raw,unit=1 -m 4096 -realtime mlock=off -smp 4,sockets=1,cores=4,threads=1 -uuid ddce4f00-e106-6864-3579-589b9ff61b8c -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-Ubuntu/monitor.sock,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew -global kvm-pit.lost_tick_policy=discard -no-hpet -no-shutdown -boot strict=on -device i82801b11-bridge,id=pci.1,bus=pcie.0,addr=0x1e -device pci-bridge,chassis_nr=2,id=pci.2,bus=pci.1,addr=0x1 -device ich9-usb-ehci1,id=usb,bus=pcie.0,addr=0x7.0x7 -device ich9-usb-uhci1,masterbus=usb.0,firstport=0,busv=charchannel0,id=channel0,name=org.qemu.guest_agent.0 -device usb-tablet,id=input0 -vnc 0.0.0.0:0,websocket=5700 -k en-us -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vgamem_mb=16,bus=pcie.0,addr=0x1 -device usb-host,hostbus=1,hostaddr=3,id=hostdev0 -device virtio-balloon-pci,id=balloon0,bus=pci.2,addr=0x4 -msg timestamp=on
Domain id=3 is tainted: high-privileges
char device redirected to /dev/pts/0 (label charserial0)
2017-01-01T18:10:31.884723Z qemu-system-x86_64: terminating on signal 15 from pid 17485
2017-01-01 18:10:32.084+0000: shutting down

With a Windows 7 VM I have had to switch to "Cirrus" as "QXL" causes the VM to lock up.  But when the lockups occur it is at the initial Windows 7 boot screen not the bios screen so it could be a different problem then yours.  However it is something for you to try.  Switch to "Advanced" mode to change from QXL to Cirrus on the VNC settings.