KVM: selftests: add powerpc support

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.


Testing Updates:
================
1. Tested this on PowerNV P9 with Radix mode. (all selftests passes)
2. Tested this on LPAR (KVM on PowerVM) case. (all selftests except-1 passes).
   The failed testcase (kvm_create_max_vcpus) is because H_GUEST_CREATE_VCPU
   (PAPR HCALL) only supports vcpu_ids 0-2047 i.e. max 2048 vcpus.
   However, kernel always returns NR_CPUS for the KVM_CAP_MAX_VCPUS extension.
   So if the LPAR kernel is built using NR_CPUS=8192, then kvm_create_max_vcpus
   can fail in __vm_vcpu_add(). This failure needs to be handled seperately,
   mostly as fix in kernel.
3. Tested these selftests changes inside x86 kvm guest  - no new failures seen.


RFC v1 -> RFC v2
================
(mostly Sashiko review comments)
1. Fixed x86's stage-2 mmu handling in patch-1 - commit msg has more description
2. Added "cc" into the clobber list for hcalls in patch-3
3. Fixed the size calculation in kvm_arch_vm_post_create in patch-3 for
   allocating 2 pages for 4K pagesize
4. Added patch-5 which prints vcpu_id in case of an error

[RFCv1]: https://lore.kernel.org/linuxppc-dev/cover.1778857539.git...
[1]: https://lore.kernel.org/all/20231120122920.293076-1-npigg...

Nicholas Piggin (4):
  KVM: selftests: Move pgd_created check into virt_pgd_alloc
  KVM: selftests: Add aligned guest physical page allocator
  KVM: PPC: selftests: add support for powerpc
  KVM: PPC: selftests: powerpc enable kvm_create_max_vcpus test

Ritesh Harjani (IBM) (1):
  KVM: selftests: Print the vcpu_id when KVM_CREATE_VCPU ioctl fails

 MAINTAINERS                                   |   2 +
 tools/testing/selftests/kvm/Makefile          |   2 +-
 tools/testing/selftests/kvm/Makefile.kvm      |  10 +
 .../testing/selftests/kvm/include/kvm_util.h  |  34 +-
 .../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 |  38 ++
 .../selftests/kvm/include/powerpc/ucall.h     |  21 +
 .../selftests/kvm/kvm_create_max_vcpus.c      |   9 +
 .../selftests/kvm/lib/arm64/processor.c       |   4 -
 tools/testing/selftests/kvm/lib/guest_modes.c |  20 +-
 tools/testing/selftests/kvm/lib/kvm_util.c    |  44 +-
 .../selftests/kvm/lib/loongarch/processor.c   |   4 -
 .../selftests/kvm/lib/powerpc/handlers.S      |  93 ++++
 .../testing/selftests/kvm/lib/powerpc/hcall.c |  45 ++
 .../selftests/kvm/lib/powerpc/processor.c     | 484 ++++++++++++++++++
 .../testing/selftests/kvm/lib/powerpc/ucall.c |  22 +
 .../selftests/kvm/lib/riscv/processor.c       |   4 -
 .../selftests/kvm/lib/s390/processor.c        |   4 -
 20 files changed, 872 insertions(+), 39 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

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2.39.5