ACS Override patch not working

[afoard]

I am attempting to run 2 VMs at the same time, passing through a graphics card to each of them. My syslinux file has the following appended:

append pcie_acs_override=downstream initrd=/bzroot

However, when I attempt to start the second VM with the graphics card enabled I get the error because the graphics cards are in the same IOMMU group. The VMs start fine independantly from each other but don't run at the same time.

Execution error

 

internal error: early end of file from monitor: possible problem:

2016-05-09T20:25:37.920002Z qemu-system-x86_64: -device vfio-pci,host=02:00.0,bus=pcie.0,multifunction=on,x-vga=on: vfio: error opening /dev/vfio/1: Device or resource busy

2016-05-09T20:25:37.920022Z qemu-system-x86_64: -device vfio-pci,host=02:00.0,bus=pcie.0,multifunction=on,x-vga=on: vfio: failed to get group 1

2016-05-09T20:25:37.920028Z qemu-system-x86_64: -device vfio-pci,host=02:00.0,bus=pcie.0,multifunction=on,x-vga=on: Device initialization failed

2016-05-09T20:25:37.920037Z qemu-system-x86_64: -device vfio-pci,host=02:00.0,bus=pcie.0,multifunction=on,x-vga=on: Device 'vfio-pci' could not be initialized

!

 

Not valid!

[SpaceInvaderOne]

Do you have any other pcie slots free on your motherboard to move a card to. On a z170 board i had i could only have cards in slot 1 and 2 , not 1 and 3, or 2 and 3 else they would not be separate