Re: [RFC PATCH 0/4] KVM selftests for s390x

[Paolo Bonzini]

On 20/05/19 13:30, Thomas Huth wrote:
>> No objections at all, though it would be like to have ucall plumbed in
>> from the beginning.
> I'm still looking at the ucall interface ... what I don't quite get yet
> is the question why the ucall_type there is selectable during runtime?
> 
> Are there plans to have test that could either use UCALL_PIO or
> UCALL_MMIO? If not, what about moving ucall_init() and ucall() to
> architecture specific code in tools/testing/selftests/kvm/lib/aarch64/
> and tools/testing/selftests/kvm/lib/x86_64 instead, and to remove the
> ucall_type stuff again (so that x86 is hard-wired to PIO and aarch64
> is hard-wired to MMIO)? ... then I could add a DIAG-based ucall
> on s390x more easily, I think.

Yes, that would work.  I think Andrew wanted the flexibility to use MMIO
on x86, but it's not really necessary to have it.

Paolo