I hopped on the IRC channel today and got the suggestion to send this to the mailing list and CC Gerd (hoping I have the right email...), hence this mail.
I've been experimenting a bit with VGA pass-through using nVidia GPUs in QEMU and attempted to take it a step further by trying to get the guest system to do SLI as well.
At the moment the pass-through itself works great (the guest could still be faster but, as you all probably know, certain flags get you a very nice 'Error Code 43' problem in your guest..)
I'm experimenting with 2 GTX 970 cards and both are working fine in the guest system, except that the nVidia driver on the guest does not currently detect that it should be able to do SLI.
Is it at all possible to use SLI with QEMU VGA pass-through at this point in time??
Some basic info of my current set-up, just in case:
Arch Linux x86_64
GPUs unbound at runtime and bound to VFIO-PCI using a shell script.
echo [pciaddr] > /sys/bus/pci/devices/[pciaddr]/driver/unbind
echo [vendor] [device] > /sys/bus/pci/drivers/vfio-pci/new_id
Windows 8.1 Pro 64 bit
GPUs attached to ioh3420 as follows (audio module as well but not included here)
-device vfio-pci,host=01:00.0,addr=00.0,bus=pcie0,multifunction=on,x-vga =on
2x Gigabyte GTX970 G1 Gaming, BIOS version F13.