[RFC 0/5] KVM: drop 32-bit host support on all architectures

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

I submitted a patch to remove KVM support for x86-32 hosts earlier
this month, but there were still concerns that this might be useful for
testing 32-bit host in general, as that remains supported on three other
architectures. I have gone through those three now and prepared similar
patches, as all of them seem to be equally obsolete.

Support for 32-bit KVM host on Arm hardware was dropped back in 2020
because of lack of users, despite Cortex-A7/A15/A17 based SoCs being
much more widely deployed than the other virtualization capable 32-bit
CPUs (Intel Core Duo/Silverthorne, PowerPC e300/e500/e600, MIPS P5600)
combined.

It probably makes sense to drop all of these at the same time, provided
there are no actual users remaining (not counting regression testing
that developers might be doing). Please let me know if you are still
using any of these machines, or think there needs to be deprecation
phase first.

      Arnd

Link: https://lore.kernel.org/lkml/Z1B1phcpbiYWLgCD@google.com/
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Crystal Wood <crwood@redhat.com>
Cc: Anup Patel <anup@brainfault.org>
Cc: Atish Patra <atishp@atishpatra.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Paul Durrant <paul@xen.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: kvm@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: kvm-riscv@lists.infradead.org
Cc: linux-riscv@lists.infradead.org

Arnd Bergmann (5):
  mips: kvm: drop support for 32-bit hosts
  powerpc: kvm: drop 32-bit booke
  powerpc: kvm: drop 32-bit book3s
  riscv: kvm: drop 32-bit host support
  x86: kvm drop 32-bit host support

 MAINTAINERS                                 |   2 +-
 arch/mips/Kconfig                           |   3 -
 arch/mips/include/asm/kvm_host.h            |   4 -
 arch/mips/kvm/Kconfig                       |   1 +
 arch/mips/kvm/emulate.c                     |   8 -
 arch/mips/kvm/msa.S                         |  12 -
 arch/mips/kvm/vz.c                          |  22 -
 arch/powerpc/include/asm/kvm_book3s.h       |  19 -
 arch/powerpc/include/asm/kvm_book3s_32.h    |  36 --
 arch/powerpc/include/asm/kvm_book3s_asm.h   |  10 -
 arch/powerpc/include/asm/kvm_booke.h        |   4 -
 arch/powerpc/include/asm/kvm_booke_hv_asm.h |   2 -
 arch/powerpc/kvm/Kconfig                    |  44 +-
 arch/powerpc/kvm/Makefile                   |  30 --
 arch/powerpc/kvm/book3s.c                   |  18 -
 arch/powerpc/kvm/book3s_32_mmu_host.c       | 396 --------------
 arch/powerpc/kvm/book3s_emulate.c           |  37 --
 arch/powerpc/kvm/book3s_interrupts.S        |  11 -
 arch/powerpc/kvm/book3s_mmu_hpte.c          |  12 -
 arch/powerpc/kvm/book3s_pr.c                | 122 +----
 arch/powerpc/kvm/book3s_rmhandlers.S        | 110 ----
 arch/powerpc/kvm/book3s_segment.S           |  30 +-
 arch/powerpc/kvm/booke.c                    | 264 ----------
 arch/powerpc/kvm/booke.h                    |   8 -
 arch/powerpc/kvm/booke_emulate.c            |  44 --
 arch/powerpc/kvm/booke_interrupts.S         | 535 -------------------
 arch/powerpc/kvm/bookehv_interrupts.S       |  10 -
 arch/powerpc/kvm/e500.c                     | 553 --------------------
 arch/powerpc/kvm/e500.h                     |  40 --
 arch/powerpc/kvm/e500_emulate.c             | 100 ----
 arch/powerpc/kvm/e500_mmu_host.c            |  54 --
 arch/powerpc/kvm/e500mc.c                   |   5 +-
 arch/powerpc/kvm/emulate.c                  |   2 -
 arch/powerpc/kvm/powerpc.c                  |   2 -
 arch/powerpc/kvm/trace_booke.h              |  14 -
 arch/riscv/kvm/Kconfig                      |   2 +-
 arch/riscv/kvm/aia.c                        | 105 ----
 arch/riscv/kvm/aia_imsic.c                  |  34 --
 arch/riscv/kvm/mmu.c                        |   8 -
 arch/riscv/kvm/vcpu_exit.c                  |   4 -
 arch/riscv/kvm/vcpu_insn.c                  |  12 -
 arch/riscv/kvm/vcpu_sbi_pmu.c               |   8 -
 arch/riscv/kvm/vcpu_sbi_replace.c           |   4 -
 arch/riscv/kvm/vcpu_sbi_v01.c               |   4 -
 arch/riscv/kvm/vcpu_timer.c                 |  20 -
 arch/x86/kvm/Kconfig                        |   6 +-
 arch/x86/kvm/Makefile                       |   4 +-
 arch/x86/kvm/cpuid.c                        |   9 +-
 arch/x86/kvm/emulate.c                      |  34 +-
 arch/x86/kvm/fpu.h                          |   4 -
 arch/x86/kvm/hyperv.c                       |   5 +-
 arch/x86/kvm/i8254.c                        |   4 -
 arch/x86/kvm/kvm_cache_regs.h               |   2 -
 arch/x86/kvm/kvm_emulate.h                  |   8 -
 arch/x86/kvm/lapic.c                        |   4 -
 arch/x86/kvm/mmu.h                          |   4 -
 arch/x86/kvm/mmu/mmu.c                      | 134 -----
 arch/x86/kvm/mmu/mmu_internal.h             |   9 -
 arch/x86/kvm/mmu/paging_tmpl.h              |   9 -
 arch/x86/kvm/mmu/spte.h                     |   5 -
 arch/x86/kvm/mmu/tdp_mmu.h                  |   4 -
 arch/x86/kvm/smm.c                          |  19 -
 arch/x86/kvm/svm/sev.c                      |   2 -
 arch/x86/kvm/svm/svm.c                      |  23 +-
 arch/x86/kvm/svm/vmenter.S                  |  20 -
 arch/x86/kvm/trace.h                        |   4 -
 arch/x86/kvm/vmx/main.c                     |   2 -
 arch/x86/kvm/vmx/nested.c                   |  24 +-
 arch/x86/kvm/vmx/vmcs.h                     |   2 -
 arch/x86/kvm/vmx/vmenter.S                  |  25 +-
 arch/x86/kvm/vmx/vmx.c                      | 117 +----
 arch/x86/kvm/vmx/vmx.h                      |  23 +-
 arch/x86/kvm/vmx/vmx_ops.h                  |   7 -
 arch/x86/kvm/vmx/x86_ops.h                  |   2 -
 arch/x86/kvm/x86.c                          |  74 +--
 arch/x86/kvm/x86.h                          |   4 -
 arch/x86/kvm/xen.c                          |  61 +--
 77 files changed, 63 insertions(+), 3356 deletions(-)
 delete mode 100644 arch/powerpc/include/asm/kvm_book3s_32.h
 delete mode 100644 arch/powerpc/kvm/book3s_32_mmu_host.c
 delete mode 100644 arch/powerpc/kvm/booke_interrupts.S
 delete mode 100644 arch/powerpc/kvm/e500.c

-- 
2.39.5