Re: [PATCH v5 0/9] KVM: selftests: add powerpc support

[Sean Christopherson <seanjc@google.com>]

On Mon, Oct 05, 2026, Ritesh Harjani wrote:
 > I think I'd even prefer to take on an #ifdef (to scope it to PPC if necessary)
> > over open coding TEST_GEN_PROGS_COMMON.
> 
> Sure, so will add this check for kvm_create_max_vcpus()
> 
> #ifdef __powerpc64__
>        TEST_REQUIRE(!is_pseries_lpar());
> #endif 

Or maybe to avoid too many ifdefs, something like:

  static inline kvm_is_ppc_pseries_lpar(void)
  {
          /*
           * Comment about how this setup has unique limitations and isn't
           * compatible with tests that create many VMs and/or vCPUs.
           */
  #ifdef __powerpc64___
          return !access("/proc/device-tree/rtas/ibm,hypertas-functions", F_OK);
  #else
          return false;
  #endif
  }

Probably redundant naming to some extent, but having "ppc" in there would make it
super obvious it's a PPC-only check.
 
> Actually I was thinking we may as well use the same check for now for
> skipping hardware_disable_test on pseries. Because there also we suffer
> from the same resource limitation. Let me know if that sounds ok to you
> or do you want us to skip kvm_create_max_vcpus() only for now, since it
> is part of TEST_GEN_PROGS_COMMON?
> 
> > LoongArch open coded its full test list
> > for some reason, and in less than a year it has started missing out on new common
> > tests.
> >
> >> (& maybe few others like vm_types_test) from that in v6.
> >
> > What's wrong with VM types test?  That one really should Just Work on all
> > architectures.  It doesn't run on LoongArch, but I assume that's
> > oversight?
> 
> So the test doesn't fail (it gets skipped). However this cap
> "KVM_CAP_VM_TYPES" is only supported on x86 and since I was planning to
> open code all common tests, hence I thought I may as well not add this
> in the first place.

/facepalm

I completely forgot KVM_CAP_VM_TYPES is x86-only.  FWIW, I'd still say use
TEST_GEN_PROGS_COMMON if possible.

> BTW, based on this discussion, I think I will re-arrange the patches in
> the following order and send a v7. (The Makefile.kvm changes will only
> get added after the main patch which adds powerpc support).
> 
> cfabdb049bd7 2026-10-05 [Ritesh Harjani (IBM)] (HEAD -> feat-ppc-kvm-selftests-new-sean-v7) KVM: selftests: Skip hardware_disable_test on pseries
> 2b51fab87b95 2026-09-22 [Ritesh Harjani (IBM)] KVM: PPC: selftests: Skip idle-page check when running nested on pseries LPAR
> f5d1de1be4e9 2026-10-05 [Ritesh Harjani (IBM)] KVM: selftests: Skip kvm_create_max_vcpus on pseries
> e45ba15cea25 2026-10-03 [Ritesh Harjani (IBM)] KVM: PPC: selftests: Add helper for checking if running nested

Doesn't this one need to come first?  Or is this different than pseries LPAR?

> 178c9bca0e20 2026-09-22 [Nicholas Piggin] KVM: PPC: selftests: add support for powerpc
> 22320662e776 2026-09-11 [Ritesh Harjani (IBM)] KVM: selftests: Fix kvm_create_max_vcpus test for powerpc

This should come before "add support for powerpc", and should have a shortlog
more like "Skip max vCPU IDs test on PPC with <whatever is a good description of the SMT cap>"

> 11b5712b213b 2026-09-22 [Ritesh Harjani (IBM)] KVM: selftests: Move memslot_perf_test off the 256M ELF load address
> 63c900860b5f 2026-09-22 [Ritesh Harjani (IBM)] KVM: selftests: Don't limit LE dirty-bitmap bitops to s390x
> 
> 
> Please let me know if this sounds ok?

Ya, works for me!