[vfio-users] vfio-pci with amd gpu in kernel 4.14.10+

[Alex Williamson]

On Fri, 12 Jan 2018 10:45:57 +0100
"P. Pronk" <vfio at pronk.nl> wrote:

> Thanks for the tips, swapping the cards is not an option as I use a uatx
> board but also use all the other pcie ports which would be blocked by
> the rx480 otherwise. Adding the vfio-pci module to initramfs doesnt make
> any difference unfortunately.
> You cant set which gpu is the primary on an Asus board. It just uses the
> one in the first pcie slot and you have no other choice, thats why I
> said I made a mistake buying Asus ;)
> 
> But everything works as intended in v4.14.9, it 'just' doesnt anymore
> since v4.14.10
> 
> @Alex, do you maybe have any suggestions? Unfortunately I am having some
> difficulties understanding the changelog of kernel v4.14.10 and their
> possible impact on my problem.

Both pci-stub.ids and vfio-pci.ids require that the pci-stub or
vfio-pci driver are loaded before the potentially conflicting driver.
Did your kernel perhaps change pci-stub from a builtin driver to a
module between these releases?  You could possibly use a softdep to get
vfio-pci loaded before amdgpu, something like

softdep amdgpu pre: vfio-pci

in modprobe.d.  Thanks,

Alex