[vfio-users] Cannot fix Error 43 for GTX 680 passed through to win 10 guest

[Alex Williamson]

On Sat, 2015-10-10 at 14:14 +0000, root at yoshi.dynu.com wrote:
> I still made no progress.
> 
> I tried with grid k2 bios, the extracted gtx680 bios as well as with 
> rombar=0 for the card. I cannot get any output for the card.
> 
> I was told that quadro/grid cards will just work as secondary card when 
> passed through, however when using an emulated card i get a code 12 (no 
> free resources for device) in windows. When trying a linux guest nouveau 
> drivers and Xorg server go berserk.
> 
> In the kvm irc channel someone told me that i should assign another 
> interrupt to the card. I don't really know how to do that. Read through 
> the man page of qemu multiple times but didn't find anything.
> 
> Also 'overflow' said that there is a way to spoof the device ID of the 
> passed through device. I cannot find any info how to do that.
> 
> Since passthrough works fine with the GT 9600 i thought that it might be 
> the motherboard and switched the cards positions on the board but no 
> difference.
> 
> Any input is welcome! Poorly re-soldering the GTX 680 back to it's 
> original state is not an option right now... ( would need to find 
> someone who is good at SMD-soldering since i am not )

I've looked through your previous logs and config and I don't have any
ideas what's wrong.  Passing a GTX680 ROM to a card that's hard mod'ed
to report itself as a K2 is pointless, PCI ROMs include the PCI IDs that
their intended for, if they don't match, they don't get run.  As I
mention in the other thread, GRID cards only run as secondary GPUs in
the VM, which you appear to be doing.  They should be completely
independent of the ROM and there's no need to use x-vga with them,
regardless of using OVMF or Seabios.

I generally only see Code 12 errors when using q35 with the GPU behind
an ioh root port, and even then, only with win7 (though I've only tried
win8.1, not win10).  Nouveau freaking out in the guest doesn't really
surprise me, most people use the nvidia driver, because why pass a
high-end GPU to a VM only to cripple it with nouveau.

Sorry, not very helpful, but I am looking at the logs you're posting and
nothing is jumping out.  Thanks,

Alex