xvga?

Hey guys

So I'm building a second server at my house for the very specific purpose of handling VMs outside of my unraid storage/docker machine.  I'm not using unraid for this second server, but I am using it as a bit of a jumping off point to figure out how to get nvidia GPU passthrough working on my server.  I'm doing this because I have successfully gotten my two nvidia gtx 970s to pass through to my windows vm on unraid 6.1.9 without hypervisor, and 6.2 with hypervisor. 

However, I'm having issues with Code 43 errors in device manager when I try this from my own server.

I've gone through and updated QEMU to the latest (2.5) and libvirt to the latest (1.3.1) and I've matched up the XML for my domain as closely to the XML generated from unraid.  I'm using VFIO and not pci-stub, and I've verified through lspci -nnk that the correct drivers are being loaded for the graphics cards.  I have a secondary nvidia gtx 730 that I'm using as the graphics card for the server as well.  However, my machine still throws code 43 on me when I pass through my 970s.

I have one discrepancy between my XML and the unraid XML and that's on the hostdevice tag - unraid has an extra attribute of xvga='yes' that my machine will not accept.  When I try to save the XML through virsh edit it complains that that attribute is not supported.  This leads me to believe that I'm missing or running an out of date package that unraid is running.

I know that the schema for my XML is defined in /usr/share/libvirt/schemas/domaincommon.rng, but updating the schema file to support xvga doesn't actually provide the underlying library support for that package (at least, that's what I would assume). 

If anyone has any insight into this I'd greatly appreciate it - I've been banging my head against a wall for a long time with this.

I'm running Ubuntu Server 16 (Xenial)...to eliminate variables I'm first documenting how to get it running on the same machine I run Unraid on, meaning the hardware is no different between unraid and my server (for now)

ASRock Extreme6 mobo

Intel Xeon 12 core processor

2x NVidia GeForce GTX 970s

NVidia GeForce GTX 730

64gb DDR4 RAM

5x 2TB WD Red HDDs

2x 250GB Samsung 850 EVO SSDs

1x 512GB Samsung 950 EVO NVMe SSD