virtualbox.org

Hi,

Yesterday, I've upgrade VirtualBox 4.0 to 4.1 on my Debian Squeeze 32 bits Host (+compiz).

I decided to try the new WDDM driver from "Guests additions" on my Windows 7 32 bits guest.

When I try to activate an Aero theme, the host display begin to "flash" (as a stroboscope) and it's practically impossible to use the Windows guest OS. I have change for a "normal" theme and all is ok.

After some tests, I can't really find out a solution. Some more informations :

- If I run the Windows guest OS with "normal" theme, change VirtualBox to "Desktop Integrated Mode", return to Windows guest and choose an Aero theme, all is ok and Aero seems to work fine. If I try to go back in "full screen mode", VirtualBox and the guests window crash.

- If I run my Squeeze host with Metacity instead of Compiz, the Windows guest have no problem with Aero/WDDM activated. Toggle between Metacity and Compiz proves that the problem comes (in part) with Compiz and have no bug with Metacity.

If someone can use Aero/WDDM driver in Windows 7 guest with a GNU/Linux guest working with Compiz, let me know.

Is there already a solution for this "problem"? Is it a known problem?

Thanks (and excuse me for my simple english)

I'd infer that having Aero on is a bit like trying to use a second compositing manager at the same time.

There's a how-to on the net about using compiz with kde4. The guy turns compiz on, then instructs to adjust the effects using kde4s system-settings desktop effects settings. Wrong! What you do is go in there and turn off desktop effects and control compiz through the compizconfig-settings-manager, also adjusting the preferred programs display manager setting from kwin to compiz. Then all works smoothly.

I've always turned off compiz or kde effects whenever using virtual machines, or even wine for that matter. Compositing is nice, but uses X rendering resources that are better left used by the operating system being virtualized, or in wine's case emulated.

In Gnome you just metacity --replace & or compiz --replace & to toggle compiz on and off. It only takes a moment but really frees up X to handle intensive stuff like virtualization. You can get away with leaving it on without a compositing manager (Aero) running virtualized, and I've occasionally forgotten and things work fine. But wine is known to be wonky with it, and I still think freeing up stuff like that when virtualizing is a good thing. Especially if you do anything with 3d gaming.

I think I read that seamless mode doesn't work when compiz (or kde effects) are on either.

Hi,

Thanks for reply.

First, I will give some more informations about my system hardware and configuration (host and guest).

Hardware : Sony VAIO VGN-NS21Z
- Intel(R) Core(TM)2 Duo CPU P8600 @ 2.40GHz
- ATI Mobility Radeon HD 3430
- DDR2 SDRAM 4096 Mo

OS Host : GNU/Linux Debian Squeeze (v 6.0.2)
- Version 32 bit
- Kernel Linux 2.6.32-5-686-Bigmem
- Gnome 2.30.2
- VGA Driver : 8.812-110104a-111995c-ATI
- Compiz 0.8.4-4 (from Debian repositories)

VirtualBox configuration :
- CPU : Share the 2 cores with 100% resources allocated + PAE/NX
- RAM : Dedicate 1536 mo with IO-APIC
- Video : Dedicate 256 mo with 3D and 2D acceleration activated
- USB2 support activated

OS Guest : Windows 7 Ultimate Edition
- Version 32 bit
- VirtualBox Guest Additions 4.1.2 r73507 correctly installed with WDDM driver instead of Direct3D

Why do I use a Windows OS ?
- I sometimes have to do maintenance on « Windev » programs (development environment + language only disponible under Windows OS) It use an USB HASP Key for registration. I can't make the USB HASP Driver running in WINE so I have to use Vbox virtualisation. All is ok with this solution, it works fine.
- I sometimes have to use Microsoft .NET developement environment for C# programming... But I often use Mono to develop under Linux OS
- Some programs for hardware initialisation as the « Logitech Unifying » witch have only Windows (and Mac) version.
- For all other uses, I do it with Debian OS of course.

Why do I use Compiz in Debian host ?
- Because the display is much fluid and fast. I use a lot of capabilities of Compiz with keyboard shortcuts. I wouldn't like to go back to Metacity. I master my desktop so mutch better with it.

Why do I want to use Aero in Windows guest ?
- Compiled Windev programs are very « heavy » and use a lot of ressources from the OS and PC. On a windows dedicated computer, Windev applications display much faster with Aero enabled than without so I want to run it like that in the virtualised Windows OS. Without Aero, some Windev applications are very slow and it's a pity to develop/test/use it.

I've made more tests and investigations with this configuration. I can give some more results :

- Metacity on host + « normal » theme on guest (not-aero) : all is ok with all VirtualBox display mode.

- Metacity on host + Aero theme on guest : all is ok with all VitualBox display mode. Except when I toggle between a host application and go back in guest OS. I have to click in the guest window to give back focus and force the display of the guest interface. Maybe a problem with the refresh display.

- Compiz on host + « normal » theme on guest (not-aero) : all is ok with all VirtualBox display mode.

- Compiz on host + Aero theme on guest : Here are mosts of the « problems »
all mode are ok now (I'll explain what was the solution after). BUT toggle between different display mode of VirtualBox will crash VirtualBox. If I want to change the display mode, I have to turn back to a normal theme on the guest before change display mode in VirtualBox. When the Vbox mode is choosen, I can go back in the guest OS and switch to Aero theme.
I have almost the same problem than with metacity when I toggle between a host application and go back in guest window : display refresh is not effecient and I this case, I have to force the refresh by a click in the guest window and open de Windows OS main menu. The guest window have a problem to redraw the interface, but I can't say if it's from host display manager or guest display manager.
Another problem that sometimes happen : the « windows manager » (uxsms) from Windows 7 crash and I have to use windows command line with « net stop uxsms » then « net start uxsms » to get back Aero working.
Last problem : Restoring a recorded guest session crash. I can't use this option in this configuration.

Conclusion :

So, these problems seems to be not so important and I think it's because the WDDM driver from guest additions is only Experimental version.

Now, I would like to know if it's because of my hardware limitation, my personal configuration or experimental WDDM driver.

The solution I find to make Aero working with Compiz without flashes display in the guest window (as a stroboscope) : Compiz general parameters were in « Autoconfiguration mode » for the refresh rate of the display. In ATI Catalyst Control Center, 60hz but in Compiz, it was 50hz. So, I do manual configuration to 60hz in Compiz Manager and the flash problems in guest window disapears.

What I think :
Maybe the host with Compiz use a different display configuration than ATI Catalyst refer. Maybe the VirtualBox virtualisation is made with ATI Catalyst configuration. If the used configuration (Compiz) is not the same than Catalyst, maybe display virtualisation will crash... Maybe there is still a difference with Vsync/Hsync configuration but I can't detect it.

Thanks for reading my experiences. If you have some more informations or an advice, I'll be happy to hear about it.

I can offer that most testing for Linux is done using a recent Nvidia card with the binary nvidia driver. I'm currently back, probably temporarily, on my older computer and switched it to my ATI Radeon x850 PRO. This forces me not to use Catalyst with the current Linux distributions as they no longer support my card. What I'm astonished at is the progress made by the free radeon driver and kernel kms, drm, etc.

I have upgraded my Debian Squeeze on this box to the latest backports kernel and xorg, mesa stuff and I can tell you that all kinds of things that never worked before without having an Nvidia card, even with the Catalyst drivers (although that was way back in time) now are working exceptionally well. Turning on aero on a Windows 7 guest in VirtualBox and having it work quite well was a huge shocker.

I use the compositing desktop (compiz or kwin) all the time with the exception of those couple (virtualization/wine) of things I mentioned. I'm only using compiz on kde4 now, having usually been satisfied with the kwin effects, because unlike my nvidia experience kwin seems to be glitchy with the effects with this card whereas compiz isn't. KDM doesn't like it either so I switched to gdm3 which works just fine as a login/logout manager.

I might try, in your case and if it isn't too much bother, experimenting with the free radeon driver. The one in Squeeze isn't the greatest so you would have to upgrade your kernel (since kms for drm 3d from what I understand is only in 2.6.38 and higher) using backports as well as the libgl1-mesa, libglu1-mesa and xserver-xorg, xorg, xserver-xorg-video-all, xserver-xorg-input-all as well.

Then again, historically 3d was much superior using Catalyst and 2d was superior using the free radeon xorg driver so perhaps things would get worse for you and not better. The r300 driver my r480 ATI chipset uses has also always been more feature filled than the newer drivers for the newer cards like you have. The newer drivers get the features eventually but so many cards use r300 that, at least in the past, things are tested out and perfected as much as they can there first before work gets done on the newer chips.

I still say that there's no reason for you to not use compositing on Linux and Aero on the Windows 7 guest but just not both at the same time. Unless your work entails it being necessary to use both at the same time of course. If that's the case then I have no hints except for waiting until more progress is made in the development. It is all getting better all the time of course.