Re: [PATCH v2 00/20] KVM: selftests: PPC pre-enabling
From: Anushree Mathur
Date: Tue Sep 29 2026 - 03:17:07 EST
On 02/09/26 10:11 PM, 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.
v2:
- Collect tags. [Itaru, Bibo]
- Use 0x180000 as the min GPA for page table pages on LoongArch, instead of
changing every other arch to use 0x200000. [Sashiko, Bibo]
- Opportunistically move the vGIC LPI stress test's global "gpa_base" variable
into setup_memslot(). [Sashiko]
v1: https://lore.kernel.org/all/20260826230511.972824-1-seanjc@xxxxxxxxxx
[*] 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: Use the common minimum GPA for page tables on
LoongArch
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 | 21 ++-
.../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, 221 insertions(+), 129 deletions(-)
base-commit: 76671054f9a1ff6abb976583cd8da37650acdc97
Hi Sean,
Thanks for working on this patch series. I tested this series (v2) as a base
for Ritesh's PowerPC KVM selftest series (v5) [1] on two real PowerPC(ppc64le)
PowerVM & PowerNV systems. Your patches applied cleanly and the core infrastructure
changes worked correctly on PowerPC — exactly the foundation Ritesh's series needed.
Ritesh's patch series : https://lore.kernel.org/linuxppc-dev/cover.1790101179.git.ritesh.list@xxxxxxxxx/
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
My Detailed testing analysis for your patches on PowerPC (ppc64le):
-------------------------------------------------
Patches 1-5 [Page allocator and memslot refactoring]
Core page allocator and memslot infrastructure exercised by all 14
tests on both systems — no regressions observed.
Patches 6-10 [Extended page allocator APIs]
Exercised via kvm_create_max_vcpus and memslot_perf_test on both
systems — APIs work correctly on PowerPC.
Patches 11-13, 16 [Memslot initialization and TEST_EXTRA region]
set_memory_region_test and memslot_modification_stress_test ran
successfully on both systems — memslot init, TEST_EXTRA region, and
its usage in set_memory_region_test all working correctly.
Patch 17 [Memory region type API]
Exercised by set_memory_region_test — PASS on both systems.
Patch 18 [Use TEST_ASSERT() in kvm_util.c]
Exercised by all tests — no assertion failures observed.
Patch 19 [Auto-pick min_gpa for PowerPC]
This is the critical patch for PPC — guest physical test memory
was correctly placed above 256M on both systems:
LPAR: guest physical test memory: [0xfffffbfff0000, 0xfffffffff0000)
bare-metal: guest physical test memory: [0xfffffbfff0000, 0xfffffffff0000)
Patch 20 [Add arch hook to force page table setup]
lib/powerpc/processor.c correctly hooks into this — guest page
tables set up correctly on both systems.
Note: Patches 14 and 15 (arm64/x86-specific TEST_EXTRA usage) were
not exercised as those tests don't build on PowerPC — as expected.
Please feel free to add :
Tested-by: Anushree Mathur <anushree.mathur@xxxxxxxxxxxxx>
Thank you,
Anushree Mathur