Re: [Qemu-devel] [Xen-devel] Cirrus VGA slow screen update, show blank screen last 13s or so for windows XP guest

[Gonglei (Arei)]

> -----Original Message-----
> From: Fabio Fantoni [mailto:address@hidden
> Sent: Thursday, July 25, 2013 9:55 PM
> To: Gonglei (Arei)
> Cc: address@hidden; address@hidden; Hanweidong;
> Luonengjun; Huangweidong (Hardware)
> Subject: Re: [Xen-devel] Cirrus VGA slow screen update, show blank screen last
> 13s or so for windows XP guest
> 
> Il 25/07/2013 15:13, Gonglei (Arei) ha scritto:
> > Hi,
> >    I found a problem: For windows XP guest booting by qemu upstream,
> > using the RDP(Remote Desktop Protocol) and VNC protocol to connect the
> windows XP guest
> > which booting by Qemu upstream respectively. the VNC client will become
> blank screen last
> > 13 seconds or so on XEN platform, and last 2 seconds on KVM. And through
> debugging,
> > the cirrus VGA card does not produce dirty pages during the blank screen's
> times.
> >
> >    When -vga is changed from cirrus to std the issue goes away and the
> update proceeds at normal speed.
> > In addition, when using the Qemu-dm replace Qemu upstream on XEN
> platform,
> > the cirrus VGA works good and the issue goes away also.
> >
> >    Today, lots of googling have seen the same behavior:
> >
> > https://github.com/joyent/smartos-live/issues/215
> > http://lists.gnu.org/archive/html/qemu-devel/2011-06/msg02105.html
> > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=574988
> > etc...
> >
> >    But, I test the latest qemu-1.5.1, the problem exist firmly.
> >
> >    Any ideas? Thanks!
> >
> > Best Regards!
> > -Gonglei
> > _______________________________________________
> > Xen-devel mailing list
> > address@hidden
> > http://lists.xen.org/xen-devel
> I've seen the perfomance problem too with vnc when I started to try
> upstream qemu. I already reported it on the end of 2011 but no solution yet.
> I found spice as an alternative: qxl vga will not work on xen until SSE
> support will be added on hvm domU, but spice is usable with stdvga and
> performance is better that vnc. Combined with vdagent and usb
> redirection it makes a perfect vkvm, and more.
> Spice basic support in xl is already present and for more features I
> posted some patches here but they are not included in upstream for now.
> Cirrus vga drivers are also old and have limitations on both windows and
> linux and they can add other problems, they are probably not good for
> recent os/de.

Thanks for responding. I don't understand why the Qemu-dm works well 
but the upstream qemu is not for the same windows XP guest image. 
Does the Cirrus vga emulation have some differences between qemu-dm 
and unstream qemu ? 

-Gonglei