P.A. Semi: "PR" KVM configure error after KVM changes for 4.12

[Christian Zigotzky]

On 09 May 2017 at 11:08 AM, Paul Mackerras wrote:
> On Tue, May 09, 2017 at 10:42:51AM +0200, Christian Zigotzky wrote:
>> Hi All,
>>
>> After the first batch of KVM changes for 4.12 merge window I get the
>> following error message if I want to configure the Linux kernel with KVM PR
>> support on my P.A. Semi board.
>>
>> warning: (KVM_BOOK3S_64) selects SPAPR_TCE_IOMMU which has unmet direct
>> dependencies (IOMMU_SUPPORT && (PPC_POWERNV || PPC_PSERIES))
>>
>> Did you change the system requirements for KVM? Does it only work on IBM
>> pSeries machines now?
> That probably came in with Alexey Kardashevskiy's patches to
> accelerate the TCE (IOMMU) hypercalls.  There was no deliberate
> intention to restrict PR KVM to IBM machines.  I'll fix it.
>
> However, I expect that at least for now we will not support PCI
> pass-through on machines other than IBM pSeries, because the KVM vfio
> code needs some specific services from the iommu layer which are
> platform-dependent and probably not implemented on other platforms
> (maple, pasemi, powermac).  If you have been using PCI pass-through
> successfully in the past with PR KVM then please let me know and we'll
> look at what is needed to keep it working.
>
> Paul.
>
Hi Paul,

Thanks a lot for your fast reply. I had to select POWERNV as well 
because without it, the kernel didn't compile. After that I tested 
Mac-on-Linux/KVM PR with the new kernel. It works without any problems.

Screenshot: https://plus.google.com/115515624056477014971/posts/fVrEXs3S3dU

It would be nice if you could fix it.

Thanks,

Christian