On Mon, Mar 27, 2023, Nicholas Piggin wrote: > On Thu Mar 23, 2023 at 3:41 AM AEST, Sean Christopherson wrote: > > On Thu, Mar 16, 2023, Michael Ellerman wrote: > > > Nicholas Piggin <npiggin@xxxxxxxxx> writes: > > > > Hi, > > > > > > > > This series adds initial KVM selftests support for powerpc > > > > (64-bit, BookS). > > > > > > Awesome. > > > > > > > It spans 3 maintainers but it does not really > > > > affect arch/powerpc, and it is well contained in selftests > > > > code, just touches some makefiles and a tiny bit headers so > > > > conflicts should be unlikely and trivial. > > > > > > > > I guess Paolo is the best point to merge these, if no comments > > > > or objections? > > > > > > Yeah. If it helps: > > > > > > Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc) > > > > What is the long term plan for KVM PPC maintenance? I was under the impression > > that KVM PPC was trending toward "bug fixes only", but the addition of selftests > > support suggests otherwise. > > We plan to continue maintaining it. New support and features has been a > bit low in the past couple of years, hopefully that will pick up a bit > though. Partly out of curiosity, but also to get a general feel for what types of changes we might see, what are the main use cases for KVM PPC these days? E.g. is it mainly a vehicle for developing and testing, hosting VMs in the cloud, something else? > > I ask primarily because routing KVM PPC patches through the PPC tree is going to > > be problematic if KVM PPC sees signficiant development. The current situation is > > ok because the volume of patches is low and KVM PPC isn't trying to drive anything > > substantial into common KVM code, but if that changes... > > Michael has done KVM topic branches to pull from a few times when such > conflicts came up (at smaller scale). If we end up with larger changes > or regular conflicts we might start up a kvm-ppc tree again I guess. A wait-and-see approach works for me. I don't have any complaints with the current process, I was just caught off guard. > > My other concern is that for selftests specifically, us KVM folks are taking on > > more maintenance burden by supporting PPC. AFAIK, none of the people that focus > > on KVM selftests in any meaningful capacity have access to PPC hardware, let alone > > know enough about the architecture to make intelligent code changes. > > > > Don't get me wrong, I'm very much in favor of more testing, I just don't want KVM > > to get left holding the bag. > > Understood. I'll be happy to maintain powerpc part of kvm selftests and > do any fixes that are needed for core code changes.If support fell away > you could leave it broken (or rm -rf it if you prefer) -- I wouldn't ask > anybody to work on archs they don't know or aren't paid to. > > Not sure if anything more can be done to help your process or ease your > mind. It (KVM and kvm-selftests) can run in QEMU at least. Updating the KVM/powerpc to include selftests would be very helpful, e.g F: tools/testing/selftests/kvm/*/powerpc/ F: tools/testing/selftests/kvm/powerpc/ and ideally there would be one or more M: (and R:) entries as well. I'm not all that concerned about the selftests support being abandoned, but the lack of specific contacts makes it look like KVM PPC is in maintenance-only mode, and it sounds like that's not the case. Thanks!
