Red Hat Bugzilla – Bug 1005037
When using “-vga qxl” together with “-display vnc=:5” or “-display sdl” qemu displays pixel garbage
Last modified: 2014-10-14 02:50:35 EDT
+++ This bug was initially created as a clone of Bug #948717 +++
qemu-1.4.0-11.fc18.x86_64 from https://fedoraproject.org/wiki/Virtualization_Preview_Repository
qemu command line:
ionice -c 3 qemu-kvm -enable-kvm -m 2048M -smp 1 -drive file=./Fedora-19-Alpha-TC4-x86_64-netinst-test.iso.qcow2,index=0,media=disk,cache=unsafe -localtime -serial file:/tmp/qemu-Fedora-19-Alpha-TC4-x86_64-netinst-test.iso.qcow2-output.log -name Fedora-19-Alpha-TC4-x86_64-netinst-test.iso.qcow2 -cdrom /local/mfabian/iso/Fedora-19-Alpha-TC4/Fedora-19-Alpha-TC4-x86_64-netinst.iso -boot c -vga qxl -display vnc=:5 -net nic -net user,hostname=Fedora-19-Alpha-TC4-x86_64-netinst-test.iso.qcow2,hostfwd=tcp::5562-:22 -monitor stdio -usb
The above commandline has “-display vnc=:5”, the problem occurs
with “-display sdl” as well though.
The result is pixel garbage, see attached screen shot.
When using “-vga std” or “-vga cirrus” instead of “-vga qxl” it works
fine, no pixel garbage.
--- Additional comment from Cole Robinson on 2013-04-14 21:55:06 CEST ---
I can reproduce with upstream. Grab F19 boot.iso here:
./x86_64-softmmu/qemu-system-x86_64 -enable-kvm -vga qxl -display sdl -cdrom ~/boot.iso -m 2048
Doing -device qxl works fine though. I also tried an F16 live cd I had hanging around and that worked fine, so maybe it's an F19 driver issue.
Alon, Gerd, thoughts?
--- Additional comment from Cole Robinson on 2013-05-28 01:01:01 CEST ---
Ping, any spice folks want to weigh in on this? Granted qxl->vnc shouldn't be a common setup, but people tend to try it out if hitting graphical issues and wanting to eliminate spice from the equation (for better or worse).
--- Additional comment from Steve Tyler on 2013-07-31 15:33:52 CEST ---
Confirming severe display corruption with the "-vga qxl" option.
With the "-vga std" option, there is no corruption.
By blindly clicking in the upper right corner, pressing the down-arrow four times, and pressing Enter twice, it is possible to power off the VM, if the corrupt display shows parts of the Welcome dialog.
Steps to reproduce:
$ qemu-kvm -m 4096 -cdrom ~/xfr/fedora/F19/Fedora-Live-Desktop-x86_64-19-1.iso -vga qxl
--- Additional comment from Jan Kratochvil on 2013-08-19 20:36:29 CEST ---
/usr/bin/qemu-kvm -m 2048 -cdrom Fedora-19-x86_64-DVD.iso -boot d -vnc :10 -vga qxl
--- Additional comment from Mike FABIAN on 2013-08-31 08:07:40 CEST ---
The problem still exists with Fedora-20-Alpha-TC2-x86_64-netinst.iso
Can not reproduce this issue:
host kernel: 2.6.32-417.el6.x86_64
Command line as follows:
ionice -c 3 /usr/libexec/qemu-kvm -M pc -nodefaults -cpu SandyBridge -enable-kvm -m 4G -smp 2,sockets=1,cores=2,threads=1 -name test -rtc base=localtime,clock=host,driftfix=slew -k en-us -boot menu=on -vga qxl -vnc :5 -monitor stdio ...
host kernel: 3.9.9-201.fc18.x86_64
Command line as follows:
ionice -c 3 qemu-kvm -enable-kvm -m 2048M -smp 1 -drive file=RHEL_65_64.qcow2,media=disk,cache=unsafe -localtime -boot c -vga qxl -display sdl -monitor stdio
Only show pixel garbage before login screen, but very fast passed. the same result with “-vga std” or “-vga cirrus”.
Re #3: RHEL-6 doesn't trigger it, try RHEL-7 or Fedora-19 as guest.
Created attachment 798084 [details]
Reproduce with host kernel 2.6.32-417.el6.x86_64
The result is pixel garbage, see attached "attachment 798084 [details]"
Reproduce this bug on qemu-kvm-0.12.1.2-2.402.el6.x86_64.
-M pc \
-cpu SandyBridge \
-m 4G \
-smp 4,sockets=2,cores=2,threads=1,maxcpus=160 \
-name rhel6.6 \
-uuid 990ea161-6b67-47b2-b803-19fb01d30d12 \
-smbios type=1,manufacturer='Red Hat',product='RHEV Hypervisor',version=el6,serial=koTUXQrb,uuid=feebc8fd-f8b0-4e75-abc3-e63fcdb67170 \
-k en-us \
-rtc base=localtime,clock=host,driftfix=slew \
-monitor stdio \
-qmp tcp:0:6666,server,nowait \
-boot menu=on,strict=on \
-bios /usr/share/seabios/bios.bin \
-chardev socket,id=seabios,path=/tmp/seabios,server,nowait \
-device isa-debugcon,chardev=seabios,iobase=0x402 \
-monitor unix:/tmp/guest-sock,server,nowait \
-vga qxl \
-vnc :0 \
-drive file=/home/rhel7-64.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads \
-device virtio-blk-pci,scsi=off,bus=pci.0,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 \
Display pixel garbage.
Created attachment 910666 [details]
snapshot of guest
Test this bug on qemu-kvm-0.12.1.2-2.428.el6.x86_64, Guest hang during boot, and display black, will attach the screenshot.
Created attachment 910670 [details]
1. Try reproduce this bug with "qxl+vnc" as bug 948717#c2 and 948717#c4 mentioned, since "-display" option has been removed from qemu-kvm, Please help check comment#11 and comment#13, if any problem please correct me.
2. Does qxl+vnc support officially, we need test this scenario in rhel6.6?
Screenshot shows two text console lines. No pixel garbage -> bug is fixed.
Guest not booting is most likely a separate (guest) bug.
Does that happen with vnc only or is spice affected too?
Just have a try, spice+qxl works well.
1. According to comment#11 comment#13 and comment#16 setting this bug to verified.
2. File a new bug 1112078 against guest desktop booting fails.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.