Problems using vfio pcie passthrough (pci-assign works)

I have a PCIe card that's behind an Intel E3-1200 PCIe x16 controller bridge that I want to use in VMs: it works when using the pci-assign driver, but something goes wrong when trying to use vfio-pci - my driver in the guest gets so far through loading before failing to talk to the hardware, so I guess something's not being setup correctly. I'm wondering if this is a bug (do vfio and OVMF work together?) or a problem with the way I'm setting up vfio-pci. I'm using the script from
http://www.linux-kvm.org/wiki/images/b/b4/2012-forum-VFIO.pdf page 30 to assign the card, but I know it's a fairly old document, and I'm running
kernel 3.11 on openSUSE: is it still correct? Or should I not try to
use vfio-pci for now?

What's the device you're trying to assign and the scripts you're using to do so? vfio-pci is fully supported, but I'd recommend a kernel newer than 3.11 (maybe a newer QEMU too, you didn't specify a version) unless openSUSE is specifically pulling vfio features and fixes into their distro. vfio does work with OVMF, most of the testing of this is with GPU assignment. It does require an OVMF image built from a fairly recent tree (not more than a few months old), but if you're getting into the guest OS you're probably fine. Provide more details and I can try to help.

Quoted 9 lines · Alex Williamson

What's the device you're trying to assign and the scripts you're using to do so? vfio-pci is fully supported, but I'd recommend a kernel newer than 3.11 (maybe a newer QEMU too, you didn't specify a version) unless openSUSE is specifically pulling vfio features and fixes into their distro. vfio does work with OVMF, most of the testing of this is with GPU assignment. It does require an OVMF image built from a fairly recent tree (not more than a few months old), but if you're getting into the guest OS you're probably fine. Provide more details and I can try to help.

Thanks, the device is a mass storage device that I work on; it's in iommu group 1 so the script I'm running is:

for i in $(ls /sys/kernel/iommu_groups/1/devices/); do

   echo $i | sudo tee \
   /sys/kernel/iommu_groups/1/devices/$i/driver/unbind
   VEN=$(cat /sys/kernel/iommu_groups/1/devices/$i/vendor)
   DEV=$(cat /sys/kernel/iommu_groups/1/devices/$i/device)
   echo $VEN $DEV | sudo tee \
   /sys/bus/pci/drivers/vfio-pci/new_id

done

I started out trying to use the version of qemu that openSUSE provides which is 1.6.2 but I also built 2.1.2 from source and that didn't help. In terms of OVMF, I've tried an OVMF-pure-efi.fd binary from
https://www.kraxel.org/repos/jenkins/edk2/ as well as building a debug OVMF.fd binary from the edk2 project
(https://github.com/tianocore/edk2/commit/23a2df76783ad7694918916f28e24cd1a1f84daf).

If you think it might help, I can certainly install a newer kernel.

Yes, try on 3.16 with QEMU 2.1 and let's go from there.

Quoted 1 line · Alex Williamson

Yes, try on 3.16 with QEMU 2.1 and let's go from there.

Upgrading to 3.16 fixed it and it all works fine now.