[PATCH v2 0/5] KVM: drop 32-bit host support on all architectures

Arnd Bergmann arnd at kernel.org
Sat Dec 21 13:42:18 PST 2024


From: Arnd Bergmann <arnd at arndb.de>

I've updated my RFC patches based on the feedback, changing mainly
the powerpc code. 

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.

I hope this can get merged through the KVM tree as a whole series.

      Arnd

---
v2 changes:
 - rebase to kvm #next branch
 - improve changelog text for x86
 - many updates for powerpc, thanks to Christophe Leroy for suggestions

Link: https://lore.kernel.org/lkml/Z1B1phcpbiYWLgCD@google.com/
Link: https://lore.kernel.org/lkml/20241212125516.467123-1-arnd@kernel.org/

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

Arnd Bergmann (5):
  mips: kvm: drop support for 32-bit hosts
  riscv: kvm: drop 32-bit host support
  powerpc: kvm: drop 32-bit booke
  powerpc: kvm: drop 32-bit book3s
  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       |  17 -
 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/include/asm/kvm_host.h         |   2 +-
 arch/powerpc/include/asm/kvm_ppc.h          |   2 +-
 arch/powerpc/include/asm/processor.h        |   3 -
 arch/powerpc/kernel/asm-offsets.c           |  21 +-
 arch/powerpc/kernel/head_32.h               |  10 -
 arch/powerpc/kernel/head_85xx.S             |  14 -
 arch/powerpc/kernel/head_book3s_32.S        |   5 -
 arch/powerpc/kernel/head_booke.h            |  39 --
 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                    | 268 ----------
 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       | 102 ----
 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                        |   2 +-
 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 +--
 85 files changed, 66 insertions(+), 3536 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




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