Re: [Qemu-devel] a user here - pci-assign

[Alex Williamson]

On Fri, 2012-09-28 at 19:46 +0100, lejeczek wrote:
> thanks Alex for your patience, appreciate it I do
> 
> what would be the droids I need?
> I'm experiencing guests' "puzzling" behavior and was 
> suggested that command line arguments were wrong/incomplete.
> 
> same box/hardware and radeon 5450 and ...
> - winXP-32bit -> OK - I assumed getting the guest on a 
> external computer monitor was an ultimate test
> - win7-64bit -> OS reports device as disabled cause the 
> device reported an error

I've had this same card working with both of these guests.  I believe
one trick on win7 was to use -cpu host.  Also, don't try to disable the
emulated vga device, just set it up like a dual-head system.  Once you
load the catalyst driver windows will switch to use the assigned device
exclusively.  I was using the new vfio assignment driver, but someone
else recently report it working with the existing driver as well.  The
5450 should be a secondary graphics card on the host system, trying to
assign the primary graphics is going to cause more problems.  Also
blacklist the radeon driver on the host, we don't need any leftover
state from the Linux driver causing problems since most of these
graphics cards don't support a reset mechanism.

> same box as above and geforce gt640 and ..
> for both XP and 7 report device with exclamation marks (thus 
> did not even bother to connect any screens like in working 
> case with XP & radeon)

I don't think we've seen any reports yet of Nvidia cards working,
there's another thread on the kvm list speculating at some of the
problems.

> I'll try to get hold of ROMs of the cards, meanwhile, how 
> can I troubleshoot it? how to get more verbose feedback and 
> what to specifically look for?

ROMs are only going to help if you're getting errors trying to read the
ROM.  Nvidia seems to have this problem, but I don't think radeons
typical do.  There's a #define in the code that can be enabled to get
more logging, but it's not terribly useful unless you know what you're
looking at.  VGA has plenty of issues with legacy PC address ranges that
are known problems, but there are also plenty of unknown problems that
make it a pretty difficult black box debugging project.  Thanks,

Alex