Re: [Xen-users] [Xen-devel] VGA passthough still not working

[Tobias Geiger <tobias.geiger@xxxxxxxxx>]

Hello Doug!

see below ....


Am Dienstag, 24. Januar 2012, 19:31:45 schrieb Doug Magee:
> On Tue, 2012-01-24 at 09:37 -0500, Tobias Geiger wrote:
> > > > > Both setup have the "flaw" that they only work once - meaning
> > 
> > you
> > 
> > > > can't reboot
> > > > 
> > > > > your DomU , cause after the reboot the passed-through Card
> > 
> > doesnt
> > 
> > > > have correct
> > > > 
> > > > > 3D-Accelleration any more (was/is the case with NVIDIA and ATI,
> > > > 
> > > > Windows XP and
> > > > 
> > > > > Windows7 )
> > > > 
> > > > For me it was with ATI with Windows7. Hadn't tried other OSes.
> > > > 
> > > > Anybody had luck with passing the card more than once to a guest?
> > 
> > With
> > 
> > > > any random set of patches?
> > 
> > I was a bit un-percice regarding the "reboot" issue:
> > 
> > The passing-through itself works even after a reboot of DomU - the
> > rebooted
> > System spits out its Graphics normaly through the passed-through Card
> > (NVIDA
> > or ATI doesnt matter here) ; BUT:
> > After a reboot it doesn't work properly. Meaning: Slow 3d Performance,
> > i.e.
> > unsable for real 3d apps, even a 3d Desktop;
> > For example, when the Card gives you 70fps in a Benchmark after a
> > fresh Cold
> > Boot, it only gives you 5-10fps after a reboot, this will be that low
> > until
> > you reboot Dom0 also, not only DomU;
> > 
> > hopefully i described the scenario better now...
> 
> Ah, got it.  I hadn't been doing anything 3D intensive, only running the
> Aero desktop.  I installed 3DMark Vantage and ran a couple of tests.  I
> get the same results (within a fraction of a %) after a cold boot as i
> do after rebooting multiple times, and always very close to native.  It
> seems i don't have the problem you're having.
> 
> Do you get any different log messages after a reboot (xl dmesg, dom0
> dmesg, qemu log)?  Have you tried with iommu=verbose to see if there's
> any more useful information there?
> 

Cool. Finally someone NOT suffering the reboot-performance-regression-Problem 
:)

I searched back and forth, rebooted DomU like crazy, diff'ed the 
dmesg/xldmesg/qemu-dm - but no difference :(

What kind of ATI Card are you passing through? 


Would be nice to find out whats causing this...

Greetings!
Tobias


> > > Yes, I've had a machine running for a couple of weeks, hosting a
> > 
> > Windows
> > 
> > > 7 domu with a passed-through Radeon 4770.  I've rebooted the virtual
> > > machine multiple times, as well as gone through a couple of xl
> > > destroy/create cycles.
> > > 
> > > I only pass it through as a secondary card, as I have the IGD as the
> > > primary on the host.  The machine is a DQ67SW with a Core i5.  This
> > 
> > is
> > 
> > > running xen-unstable (c/s 24465) on a 3.2.1 dom0, with no extra
> > 
> > patches.
> > 
> > > I haven't, however, had any luck passing through the IGD to anything
> > > other than a Windows XP, and that includes running the latest
> > 
> > qemu-xen
> > 
> > > with Jean's patches (opregion, host bridge config space mapping).
> > 
> > I've
> > 
> > > been intending to start a separate thread for that...
> > 
> > _______________________________________________
> > Xen-users mailing list
> > Xen-users@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-users


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