Re: [PATCH 00/20] KVM: selftests: PPC pre-enabling

[Itaru Kitayama]

On Wed, Aug 26, 2026 at 04:04:51PM -0700, Sean Christopherson wrote:
> This is a big pile of cleanups and refactoring to prepare for PPC support in
> KVM selftests.  PPC has paging modes that require multi-page page tables, and
> those page tables need to be naturally aligned.  The original proposal was to
> plumb in an @align param to the page allocators[*], but I didn't love the idea
> of adding another rarely used param to the allocators.
> 
> Reworking the APIs to take a region type requires a fair bit of churn, and was
> more painful than expected as I didn't realize just how many one-off tests did
> weird things, but overall I think it's worth it?  If only to keep cutting down
> on the use of magic memslot numbers in tests.
> 
> This needs explicit testing on s390.  I tested on arm64 and x86, and given the
> number of failures I had to wade through, I wouldn't be at all suprised if I
> broke something subtle on s390 as well.
> 
> I'm less concerned about RISC-V and LoongArch as they don't have any custom
> tests that are affected (which is where I got burned).

I ran kvm_page_table_test with this series applied on Grace CPUs.

Passes across all the arm64 guest modes supported.

Tested-by: Itaru Kitayama <itaru.kitayama@xxxxxxxxxxx>

> 
> [*] https://lore.kernel.org/all/df86b5ccdbdafc3509d9538bd5e6796737bab2db.1781093720.git.ritesh.list@xxxxxxxxx
> 
> Nicholas Piggin (1):
>   KVM: selftests: Use goto instead of do-while to retry finding unused
>     physical pages
> 
> Sean Christopherson (19):
>   KVM: selftests: Use MEM_REGION_PT memslot instead of '0' for s390
>     regions/segments
>   KVM: selftests: Bump the minimum GPA for page tables to 0x200000
>   KVM: selftests: Use vm_alloc_page_table() to allocate LoongArch page
>     tables
>   KVM: selftests: Rename "num" param to "nr_pages" for physical page
>     allocators
>   KVM: selftests: Extend page allocator to support naturally aligned
>     allocations
>   KVM: selftests: Make the single-page allocator APIs static inline
>   KVM: selftests: Use the innermost page allocator API in the memslot
>     perf test
>   KVM: selftests: Use the innermost page allocator API in s390's IRQ
>     routing test
>   KVM: selftests: Add a wrapper API to allocate multiple page table
>     pages
>   KVM: selftests: Initialize vm->memslots[] with invalid memslots during
>     creation
>   KVM: selftests: Add APIs to override memory region types with custom
>     memslots
>   KVM: selftests: Add TEST_EXTRA memory region type for "special"
>     memslots
>   KVM: selftests: Use TEST_EXTRA region in arm64's vGIC LPI stress test
>   KVM: selftests: Use TEST_EXTRA region in x86's smaller MAXPHYADDR test
>   KVM: selftests: Use TEST_EXTRA region in set memory region test
>   KVM: selftests: Take the memory region type, not memslot, in page
>     allocators
>   KVM: selftests: Use TEST_ASSERT(), not assert(), in
>     vm_get_mem_region()
>   KVM: selftests: Automatically pick min_gpa for allocations based on
>     region type
>   KVM: selftests: Add arch hook to force page tables to be naturally
>     aligned
> 
>  .../selftests/kvm/arm64/page_fault_test.c     |  18 ++-
>  .../selftests/kvm/arm64/vgic_lpi_stress.c     |  19 ++-
>  .../testing/selftests/kvm/include/kvm_util.h  | 106 +++++++++++++--
>  tools/testing/selftests/kvm/include/x86/smm.h |   2 +-
>  .../selftests/kvm/lib/arm64/processor.c       |   4 +-
>  tools/testing/selftests/kvm/lib/kvm_util.c    | 127 +++++++++++-------
>  .../selftests/kvm/lib/loongarch/processor.c   |   5 +-
>  .../selftests/kvm/lib/riscv/processor.c       |   4 +-
>  .../selftests/kvm/lib/s390/processor.c        |   7 +-
>  .../testing/selftests/kvm/lib/x86/processor.c |  15 ++-
>  .../testing/selftests/kvm/memslot_perf_test.c |   3 +-
>  tools/testing/selftests/kvm/s390/cmma_test.c  |  19 +--
>  .../testing/selftests/kvm/s390/irq_routing.c  |   2 +-
>  .../selftests/kvm/set_memory_region_test.c    |   8 +-
>  .../x86/smaller_maxphyaddr_emulation_test.c   |   9 +-
>  15 files changed, 219 insertions(+), 129 deletions(-)
> 
> 
> base-commit: 76671054f9a1ff6abb976583cd8da37650acdc97
> -- 
> 2.55.0.887.g758fc8c411-goog
>