Some pointers on KVM, GPU Pass Through, and Syslinux.cfg

[jude]

I have passthrough working with a single MSI GTX970 GPU on an AMD motherboard (GA990FXA-UD5) with the same AMD CPU.

 

I noticed that your syslinux.cfg file did not have a lot of the AMD specific info that is recommended. This could be part of your problem.

 

my syslinux.cfg file includes the following

 

append amd_iommu=on iommu=pt iommu=1 vfio_iommu_type1.allow_unsafe_interrupts=1 pcie_acs_override=downstream initrd=/bzroot

 

but as always ymmv.

[Mettbrot]

Syslinux.cfg 101

The only statement you WILL need in there to ensure clean operations with VFIO is this: 

pcie_acs_override=downstream

 

Hey! Do I need this for every VM or only if I want to passthrough a GPU?

I only want to passthrough USB devices...

[jonp]

Syslinux.cfg 101

The only statement you WILL need in there to ensure clean operations with VFIO is this: 

pcie_acs_override=downstream

 

Hey! Do I need this for every VM or only if I want to passthrough a GPU?

I only want to passthrough USB devices...

That syslinux line is for PCI device pass through.  If you are not passing through any PCI devices to any VM, you don't need it.

[Monkeyair]

When setting up a VM through the GUI to enable PCI passthrough of tuners, would I need to amend any cfg or go files?

 

I tried to setup a VM to run Ubuntu, but failed to passthrough my devices.