[virt-tools-list] [Spice-devel] [libvirt] qemu qxl video memory parameter - windows bsod with spice

Gianluca Cecchi gianluca.cecchi at gmail.com
Wed May 4 19:40:45 UTC 2011

On Wed, May 4, 2011 at 6:05 PM, Daniel P. Berrange <berrange at redhat.com> wrote:
> On Wed, May 04, 2011 at 07:52:37PM +0400, Emre Erenoglu wrote:
>> Hi,
>> Please see the below discussion with the spice community.
>> libvirt is adding a parameter about video ram to qemu process and this
>> parameter might be responsible of a crash in the qxl at higher resolutions.
>> Spice people tell me that their default ram should be 64 Mbytes.
>> I'm using libvirt 0.9.0 and qemu 0.14,  virt-manager 0.8.7. When configuring
>> a guest in virt-manager, cirrus driver is added as default, then you can
>> change it to qxl, but the 9 MB videoram parameter can't be adjusted and it
>> does not automatically change to 64 MB. If you add a 2nd qxl video card,
>> then it has 64 MB memory.
>> The parameter that qemu gets with one qxl device is:
>>      -vga qxl -global qxl-vga.vram_size=9437184
>> The parameter that qemu gets with a second qxl device is:
>>      -vga qxl -global qxl-vga.vram_size=9437184 -device
>> qxl,id=video1,vram_size=67108864,bus=pci.0,addr=0x8
>> Is this a bug in libvirt or other related tools?
> libvirt allows arbitrary RAM specification for QXL, so I
> think it is probably a virt-manager issue. When changing
> the display type from cirrus -> qxl, virt-manager should
> probably just remove any RAM attribute in the XML and let
> libvirt re-assign the default setting
> Daniel

Actually on my Fedora 14 + virt-preview repo, that comes with a lower
libvirt version, in particular:

I do have in virt-manager inside the section "video":
Model: qxl
RAM: 9MB (not changeable, like a note)

but my qemu-kvm line for a w2k3 32bit guest is:
[ ~]$ ps -ef|grep qemu
qemu     17973     1 24 18:11 ?        00:49:12 /usr/bin/qemu-kvm -S
-M fedora-13 -cpu core2duo,+x2apic -enable-kvm -m 1536 -smp
1,sockets=1,cores=1,threads=1 -name w2k3 -uuid
5ee312e2-2e2e-4503-f1c2-749592bb6ca8 -nodefconfig -nodefaults -chardev
-mon chardev=charmonitor,id=monitor,mode=control -rtc base=localtime
-boot dc -device
virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x6 -drive
if=none,media=cdrom,id=drive-ide0-1-0,readonly=on,format=raw -device
ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -drive
-device ide-drive,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1
-netdev tap,fd=21,id=hostnet0 -device
-chardev pty,id=charserial0 -device
isa-serial,chardev=charserial0,id=serial0 -chardev
spicevmc,id=charchannel0,name=vdagent -device
-usb -device usb-tablet,id=input0 -spice
-vga qxl -device AC97,id=sound0,bus=pci.0,addr=0x5 -device

So the -qxl part doesn't get the "-global qxl-vga.vram_size" option
set at all.....
Does this mean that it gets the default 64Mb?
Perhaps a regression in 0.9.0?


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