[PATCH v2 00/12] KVM: selftests: Add more syscall wrappers, fix hardware_disable_test

[Sean Christopherson <seanjc@google.com>]

Buried in the middle of this is a fix for the hardware_disable_test where
it can end up with a runtime of multiple minutes when running a preemptible
kernels on a large NUMA system.  Turns out my analysis/guess in v1 was wrong;
the problem isn't direct CPU contention, it's that letting the workers do any
amount of "real" work on any CPUs leads to pthread_create() slowdowns from
the perspective of the caller.

The vast, vast majority of the changes are adding kvm_xxx() syscall wrappers
so that tests don't need to manually assert that a syscall succeeds (the
hardware disable test had some ugly equivalents).

As with v1, I'm planning on taking this through kvm-x86.

v2:
 - pause() the child after creating workers so as not to busy loop, and to
   maintain equivalent functionality. [Sashiko]
 - Don't bother pinning the parent of immediate child, and instead focus on
   affining workers to their CPUs asap.

v1: https://lore.kernel.org/all/20260730191908.2084803-1-seanjc@google.com

Sean Christopherson (12):
  KVM: selftests: Add a KVM syscall wrapper for sched_setaffinity()
  KVM: selftests: Set threads CPU affinity before doing work in hardware
    disable test
  KVM: selftests: Pre-set threads affinity in hardware disable test when
    possible
  KVM: selftests: Return the target CPU from pin_task_to_random_cpu()
  KVM: selftests: Extract picking of random CPU from cpu_set_t to
    separate API
  KVM: selftests: Affine threads to random CPUs in hardware disable test
  KVM: selftests: Drop unreachable, dead code from hardware disable test
  KVM: selftests: Add KVM syscall wrapper for pthread_create()
  KVM: selftests: Add KVM syscall wrappers for pthread_{cancel,join}()
  KVM: selftests: Add helper APIs to cancel+join pthreads
  KVM: selftests: Add KVM syscall wrappers for
    pthread_{g,s}etaffinity_np()
  KVM: selftests: Clean up global constants in hardware disable test

 tools/testing/selftests/kvm/arch_timer.c      |  18 +--
 tools/testing/selftests/kvm/arm64/vgic_irq.c  |  14 +--
 .../selftests/kvm/arm64/vgic_lpi_stress.c     |   8 +-
 tools/testing/selftests/kvm/dirty_log_test.c  |   4 +-
 .../selftests/kvm/hardware_disable_test.c     | 103 ++++++++----------
 .../selftests/kvm/include/kvm_syscalls.h      |  48 ++++++++
 .../testing/selftests/kvm/include/kvm_util.h  |  11 +-
 tools/testing/selftests/kvm/irq_test.c        |   4 +-
 tools/testing/selftests/kvm/irqfd_test.c      |   4 +-
 .../selftests/kvm/kvm_page_table_test.c       |   6 +-
 tools/testing/selftests/kvm/lib/kvm_util.c    |  10 +-
 tools/testing/selftests/kvm/lib/memstress.c   |   4 +-
 .../selftests/kvm/lib/userfaultfd_util.c      |   7 +-
 .../testing/selftests/kvm/memslot_perf_test.c |   4 +-
 tools/testing/selftests/kvm/mmu_stress_test.c |   4 +-
 .../selftests/kvm/pre_fault_memory_test.c     |   4 +-
 tools/testing/selftests/kvm/rseq_test.c       |  12 +-
 tools/testing/selftests/kvm/s390/memop.c      |   4 +-
 .../selftests/kvm/set_memory_region_test.c    |   6 +-
 tools/testing/selftests/kvm/steal_time.c      |   6 +-
 tools/testing/selftests/kvm/x86/hyperv_ipi.c  |  32 +-----
 .../selftests/kvm/x86/hyperv_tlb_flush.c      |  30 +----
 .../kvm/x86/private_mem_conversions_test.c    |   4 +-
 .../kvm/x86/private_mem_kvm_exits_test.c      |   7 +-
 .../selftests/kvm/x86/recalc_apic_map_test.c  |   5 +-
 .../selftests/kvm/x86/sev_migrate_tests.c     |   4 +-
 .../selftests/kvm/x86/sync_regs_test.c        |   5 +-
 .../selftests/kvm/x86/tsc_scaling_sync.c      |   4 +-
 .../selftests/kvm/x86/xapic_ipi_test.c        |  31 +-----
 .../selftests/kvm/x86/xen_shinfo_test.c       |  10 +-
 30 files changed, 183 insertions(+), 230 deletions(-)


base-commit: 3c7d7f908d574277a845423ec32250a8d8df44c8
-- 
2.55.0.508.g3f0d502094-goog