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

[Anushree Mathur <anushree.mathur2@ibm.com>]

On 22/09/26 11:58 PM, Ritesh Harjani (IBM) wrote:
> Patch v4 -> v5:
> ==============
> - Fixed the issues reported by Anushree while running on kvm on powervm
>    (nested).
> - Fixed memslot_perf_test on powerpc.
>
> PATCH v3 -> PATCH v4:
> ==================
> - Rebased on top of Sean's new page allocator patch series v2 [1]
>    This allowed to drop and patch-2 since it will now come from Sean's
>    v2.
> - Addressed review comments from Sean - squashed patches 6-10 in patch-1 of
>    this.
> - Dropped patch-5 to print vcpu_id when KVM_CREATE_VCPU ioctl fails.
> - Added additional patch-3 to this series to allow dirty_log_test to run on all
>    big-endian machines.
>
> [1]: https://lore.kernel.org/kvm/20260902164123.2546762-1-seanjc@google.com/
> [v3]: https://lore.kernel.org/linuxppc-dev/2d2c46be7f051c7f1c645afaec67f57067d37a81.1781093720.git.ritesh.list@gmail.com/
>
> Testing updates:
> ================
> I have done some fair amount of testing of the selftests both on real HW and
> using various combinations on qemu (powernv+LE (default), pseries+cap-nested-hv,
> pseries+cap-nested-papr, powernv+BE). There were few powerpc kvm kernel fixes
> which were identified as part of this work. I will send those patches separately
> as those anyway needs to go in separately.
>
> <pasted snippet of cover letter from previous versions>
> =======================================================
>
> Hi All,
>
> This series primarly adds KVM selftests support for powerpc (64-bit, BookS,
> radix MMU).
>
> This patch series is originally Nick's work. I have mainly only rebased it on
> the latest upstream tree. Since the rebase required few changes to all the four
> patches (Patch 1-4), I have dropped the earlier Acked-by from Michael Ellerman.
>
> Since the last series was posted three years ago [1], I am resetting the version
> to RFC. This rebase was done as part of a larger effort to improve the selftests
> infrastructure for Linux on PowerPC tree. Thanks to Harsh and Maddy for their
> help on this.
>
>
> Nicholas Piggin (1):
>    KVM: PPC: selftests: add support for powerpc
>
> Ritesh Harjani (IBM) (8):
>    KVM: selftests: Enable kvm_create_max_vcpus test for powerpc
>    KVM: selftests: Don't limit LE dirty-bitmap bitops to s390x
>    KVM: selftests: Split out a KVM_CREATE_VCPU helper that can fail
>    KVM: selftests: Make kvm_create_max_vcpus tolerate ENOMEM
>    KVM: selftests: Limit the number of VM creates in hardware_disable_test
>    KVM: PPC: selftests: Make nested case on pseries LPARs as resource constrained
>    KVM: PPC: selftests: Skip idle-page check when running nested on pseries LPAR
>    KVM: selftests: Move memslot_perf_test off the 256M ELF load address
>
>   MAINTAINERS                                   |   2 +
>   tools/testing/selftests/kvm/Makefile          |   2 +-
>   tools/testing/selftests/kvm/Makefile.kvm      |  10 +
>   .../selftests/kvm/access_tracking_perf_test.c |  11 +
>   tools/testing/selftests/kvm/dirty_log_test.c  |  12 +-
>   .../selftests/kvm/hardware_disable_test.c     |   7 +-
>   .../testing/selftests/kvm/include/kvm_util.h  |  13 +
>   .../selftests/kvm/include/powerpc/hcall.h     |  17 +
>   .../kvm/include/powerpc/kvm_util_arch.h       |  22 +
>   .../selftests/kvm/include/powerpc/ppc_asm.h   |  32 ++
>   .../selftests/kvm/include/powerpc/processor.h |  46 ++
>   .../selftests/kvm/include/powerpc/ucall.h     |  21 +
>   .../selftests/kvm/kvm_create_max_vcpus.c      |  29 +-
>   tools/testing/selftests/kvm/lib/guest_modes.c |  20 +-
>   tools/testing/selftests/kvm/lib/kvm_util.c    |  39 +-
>   .../selftests/kvm/lib/powerpc/handlers.S      |  93 ++++
>   .../testing/selftests/kvm/lib/powerpc/hcall.c |  45 ++
>   .../selftests/kvm/lib/powerpc/processor.c     | 522 ++++++++++++++++++
>   .../testing/selftests/kvm/lib/powerpc/ucall.c |  22 +
>   .../testing/selftests/kvm/memslot_perf_test.c |   2 +-
>   20 files changed, 942 insertions(+), 25 deletions(-)
>   create mode 100644 tools/testing/selftests/kvm/include/powerpc/hcall.h
>   create mode 100644 tools/testing/selftests/kvm/include/powerpc/kvm_util_arch.h
>   create mode 100644 tools/testing/selftests/kvm/include/powerpc/ppc_asm.h
>   create mode 100644 tools/testing/selftests/kvm/include/powerpc/processor.h
>   create mode 100644 tools/testing/selftests/kvm/include/powerpc/ucall.h
>   create mode 100644 tools/testing/selftests/kvm/lib/powerpc/handlers.S
>   create mode 100644 tools/testing/selftests/kvm/lib/powerpc/hcall.c
>   create mode 100644 tools/testing/selftests/kvm/lib/powerpc/processor.c
>   create mode 100644 tools/testing/selftests/kvm/lib/powerpc/ucall.c
>
> --
> 2.39.5
>
>
Hi Ritesh,
Thanks for working on the fixes, I tested this series (v5) on top of 
Sean's pre-enabling series (v2) [1]
on two real PowerPC systems. All patches applied cleanly and the tests
work correctly on both PowerVM LPAR and PowerNV bare-metal.

[1]: https://lore.kernel.org/kvm/20260902164123.2546762-1-seanjc@google.com/



Full test suite summary (make run_tests):
-----------------------------------------
                                    LPAR    bare-metal
   demand_paging_test               PASS      PASS
   dirty_log_test                   PASS      PASS
   dirty_log_perf_test              PASS      PASS
   guest_print_test                 PASS      PASS
   hardware_disable_test            PASS      PASS
   kvm_binary_stats_test            PASS      PASS
   kvm_create_max_vcpus             PASS      PASS
   kvm_page_table_test              PASS      PASS
   set_memory_region_test           PASS      PASS
   memslot_modification_stress_test PASS      PASS
   memslot_perf_test                PASS      PASS
   access_tracking_perf_test        PASS      PASS
   irqfd_test                       SKIP      SKIP
   vm_types_test                    SKIP      SKIP
   --------------------------------------------------
   Total                         12 PASS   12 PASS
                                  2 SKIP    2 SKIP


Per-patch validation:
---------------------
Patch 1 [KVM: PPC: selftests: add support for powerpc]
   All 14 tests built and ran successfully on PowerPC — the core
   infrastructure (lib/powerpc/processor.c, handlers.S, ucall.c,
   hcall.c) works correctly on both systems.

Patch 2 [KVM: selftests: Enable kvm_create_max_vcpus test for powerpc]
   kvm_create_max_vcpus ran successfully on both systems.

Patch 3 [KVM: selftests: Don't limit LE dirty-bitmap bitops to s390x]
   dirty_log_test ran successfully on both systems for both 4K and
   64K page modes (big-endian dirty-bitmap bitops working correctly).

Patch 4 [KVM: selftests: Split out a KVM_CREATE_VCPU helper that can fail]
   KVM_CREATE_VCPU helper exercised by kvm_create_max_vcpus on both
   systems — clean failure path confirmed on LPAR (ENOMEM at vCPU 72).

Patch 5 [KVM: selftests: Make kvm_create_max_vcpus tolerate ENOMEM]
   LPAR:       Created 72 vCPUs before ENOMEM at id 72 — test
               completed gracefully without crash or assert.
   bare-metal: Successfully created all 2048 vCPUs — no ENOMEM hit.

Patch 6 [KVM: selftests: Limit the number of VM creates in 
hardware_disable_test]
   hardware_disable_test ran successfully on both systems without
   hitting OOM — VM create limiting working correctly on LPAR.

Patch 7 [KVM: PPC: selftests: Make nested case on pseries LPARs as 
resource constrained]
   access_tracking_perf_test correctly identified the LPAR as a
   resource-constrained nested environment and adjusted accordingly.

Patch 8 [KVM: PPC: selftests: Skip idle-page check when running nested 
on pseries LPAR]
   LPAR:
     Skipping idle page count sanity check, because the test is run nested
     [idle-page check correctly skipped on nested pseries LPAR]
   bare-metal:
     [No skip message — idle-page sanity check ran in full on PowerNV]

Patch 9 [KVM: selftests: Move memslot_perf_test off the 256M ELF load 
address]
   memslot_perf_test ran successfully on both systems — ELF load
   address conflict with PPC's 256M region resolved correctly.

Notes on SKIPs:
---------------
   - irqfd_test:   PowerPC has no in-kernel irqchip.
                   1..0 # SKIP - Requirement not met: 
kvm_arch_has_default_irqchip()
                   Pre-existing, unrelated to this series.

   - vm_types_test: KVM_CAP_VM_TYPES is x86-only (SEV-SNP/TDX).
                   1..0 # SKIP - Requirement not met: 
kvm_has_cap(KVM_CAP_VM_TYPES)
                   Pre-existing, unrelated to this series.


Please feel free to add :

Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>

Thank you,
Anushree Mathur