VGA Passthru HW upgrade

VGA Passthru HW upgrade

[Pavel Mateja]

Hi,
I've upgraded my XEN system with Windows 7 virtual hosts to:
MB: ASUS Crosshair V Formula (BIOS 1102)
CPU: AMD FX-8150
which is basically working bus seems to be less stable than old system.

I tried to upgrade BIOS on Formula IV but linux failed to boot the FX even on 
baremetal.

I can't hear sound in DomU. Hmm, to be honest I've heard some broken pieces,..

I tried to pass AMD HD7970 but the VGA BIOS init has probably been changed and 
virtual machine won't start.

And there is one more stange thing (even on old system):
lspci in Dom0 and GPU-Z in virtual machine reports only 2,5GT/s (PCI-E 1.1) on 
PCI-E for VGA while the same kernel on baremetal reports 5GT/s (PCI-E 2.0).
-- 
Pavel Mateja

Re: VGA Passthru HW upgrade

[Pavel Matěja]

Hi again,
I made some stupid mistakes in my build. The passthru is working of course.
You can add another working system to Wiki:
MB: ASUS Crosshair V Formula (BIOS 1102)
CPU: AMD FX-8150
VGA: ASUS HD7970
Since all 7970s have same BIOS they should all work.

There was just one small problem. I have both HD7970 and HD6850 in computer 
right now.
If you want to run Virtual machines with different cards you have to load righ 
BIOS for each one.
Because I can't find HD7970 BIOS to download yet I had to make it primary and 
copy BIOS from RAM while HD6850 got it from file.
I'll try to write patch which will tell XEN the VGA BIOS location per virtual 
server basis.
-- 
Pavel Mateja

Re: VGA Passthru HW upgrade

[Pasi Kärkkäinen]

On Sat, Jan 21, 2012 at 12:37:45PM +0100, Pavel Mat??ja wrote:
> Hi again,
> I made some stupid mistakes in my build. The passthru is working of course.
> You can add another working system to Wiki:
> MB: ASUS Crosshair V Formula (BIOS 1102)
> CPU: AMD FX-8150
> VGA: ASUS HD7970
> Since all 7970s have same BIOS they should all work.
> 

Great!

> There was just one small problem. I have both HD7970 and HD6850 in computer 
> right now.
> If you want to run Virtual machines with different cards you have to load righ 
> BIOS for each one.
> Because I can't find HD7970 BIOS to download yet I had to make it primary and 
> copy BIOS from RAM while HD6850 got it from file.
> I'll try to write patch which will tell XEN the VGA BIOS location per virtual 
> server basis.

That would be much appreciated!

-- Pasi

Re: VGA Passthru HW upgrade

[Pavel Mateja]

> I can't hear sound in DomU. Hmm, to be honest I've heard some broken
> pieces,..

Problem found:
You can't load linux ALSA driver before you pass the sound card to the virtual 
machine. Since I removed linux kernel driver Windows play sounds just fine.
-- 
Pavel Mateja

Re: VGA Passthru HW upgrade

[Pasi Kärkkäinen]

On Wed, Jan 25, 2012 at 09:26:45AM +0100, Pavel Mateja wrote:
> > I can't hear sound in DomU. Hmm, to be honest I've heard some broken
> > pieces,..
> 
> Problem found:
> You can't load linux ALSA driver before you pass the sound card to the virtual 
> machine. Since I removed linux kernel driver Windows play sounds just fine.
>

Thanks for the update. And that's quite obvious reason..
naturally you can't use a single PCI device in multiple domains at the same time.

PCI passthru *dedicates* the device to specific domain, so it can only be used in that domain.
If dom0 is trying to use it aswell, things will go wrong.

-- Pasi

Re: VGA Passthru HW upgrade

[Pavel Matěja]

On Wed 25. of January 2012 17:18:28 you wrote:
> On Wed, Jan 25, 2012 at 09:26:45AM +0100, Pavel Mateja wrote:
> > > I can't hear sound in DomU. Hmm, to be honest I've heard some broken
> > > pieces,..
> > 
> > Problem found:
> > You can't load linux ALSA driver before you pass the sound card to the
> > virtual machine. Since I removed linux kernel driver Windows play sounds
> > just fine.
> 
> Thanks for the update. And that's quite obvious reason..
> naturally you can't use a single PCI device in multiple domains at the same
> time.
> 
> PCI passthru *dedicates* the device to specific domain, so it can only be
> used in that domain. If dom0 is trying to use it aswell, things will go
> wrong.
> 
> -- Pasi

I know that.
I power down USB controller and rescan PCI because of resource_allignment and 
I unbind all the devices (USB, VGA, Sound Card) from drivers.
Just sound card didn't work well after this.
Strange thing is the sound was working on Crosshair IV Formula.
I suppose linux driver sets up the card in way Windows can't handle.
Funny thing: sound worked in analog in Battlefield 3 but not plain Win7. No 
single beep from SPDIF. One big WTF?
-- 
Pavel Mateja