[RFC PATCH 00/18] KVM hardware enable/disable reorganize

[isaku . yamahata]

From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

The purpose of this patch series is to get feedback before going further.
e.g. rebasing TDX KVM series, etc.

This patch series is to implement the suggestion by Sean Christopherson [1]
to reorganize enable/disable cpu virtualization feature by replacing
the arch-generic current enable/disable logic with PM related hooks. And
convert kvm/x86 to use new hooks.

- Untable x86 hardware enable logic, snapshot MSRs for user return notifier,
  enabling cpu virtualization on cpu online and platform resume. and real
  enabling of CPU virtualization feature
- Introduce hooks related to PM.
- Convert kvm/x86 code to user those hooks.
- Split out hardware enabling/disabling logic into a separate file.  Compile
  it for non-x86 code.  Once conversion of other KVM archs is done, this file
  can be dropped.
- Delete cpus_hardware_enabled. 17/18 and 18/18

[1] https://lore.kernel.org/kvm/YvU+6fdkHaqQiKxp@xxxxxxxxxx/

Chao Gao (2):
  KVM: x86: Move check_processor_compatibility from init ops to runtime
    ops
  Partially revert "KVM: Pass kvm_init()'s opaque param to additional
    arch funcs"

Isaku Yamahata (16):
  KVM: x86: Drop kvm_user_return_msr_cpu_online()
  KVM: x86: Use this_cpu_ptr() instead of
    per_cpu_ptr(smp_processor_id())
  KVM: Drop kvm_count_lock and instead protect kvm_usage_count with
    kvm_lock
  KVM: Add arch hooks for PM events with empty stub
  KVM: x86: Move TSC fixup logic to KVM arch resume callback
  KVM: Add arch hook when VM is added/deleted
  KVM: Move out KVM arch PM hooks and hardware enable/disable logic
  KVM: kvm_arch.c: Remove _nolock post fix
  KVM: kvm_arch.c: Remove a global variable, hardware_enable_failed
  KVM: Do processor compatibility check on cpu online and resume
  KVM: x86: Duplicate arch callbacks related to pm events
  KVM: Eliminate kvm_arch_post_init_vm()
  KVM: x86: Delete kvm_arch_hardware_enable/disable()
  KVM: Add config to not compile kvm_arch.c
  KVM: x86: Remove cpus_hardware_enabled and related sanity check
  KVM: Remove cpus_hardware_enabled and related sanity check

 Documentation/virt/kvm/locking.rst |  14 +--
 arch/arm64/kvm/arm.c               |   2 +-
 arch/mips/kvm/mips.c               |   2 +-
 arch/powerpc/kvm/powerpc.c         |   2 +-
 arch/riscv/kvm/main.c              |   2 +-
 arch/s390/kvm/kvm-s390.c           |   2 +-
 arch/x86/include/asm/kvm-x86-ops.h |   1 +
 arch/x86/include/asm/kvm_host.h    |   2 +-
 arch/x86/kvm/Kconfig               |   1 +
 arch/x86/kvm/svm/svm.c             |   4 +-
 arch/x86/kvm/vmx/vmx.c             |  14 +--
 arch/x86/kvm/x86.c                 | 184 ++++++++++++++++++++++-------
 include/linux/kvm_host.h           |  14 ++-
 virt/kvm/Kconfig                   |   3 +
 virt/kvm/Makefile.kvm              |   3 +
 virt/kvm/kvm_arch.c                | 119 +++++++++++++++++++
 virt/kvm/kvm_main.c                | 177 ++++++++-------------------
 17 files changed, 349 insertions(+), 197 deletions(-)
 create mode 100644 virt/kvm/kvm_arch.c

-- 
2.25.1