[PATCH 00/10] KVM: VMX: Unionize vcpu_vmx.exit_reason

[Sean Christopherson]

Convert the exit_reason field in struct vcpu_vmx from a vanilla u32 to a
union, (ab)using the union to provide access to the basic exit reason and
flags.

There are three motivating factors for making exit_reason a union:

  - Help avoid bugs where a basic exit reason is compared against the full
    exit reason, e.g. there have been two bugs where MCE_DURING_VMENTRY
    was incorrectly compared against the full exit reason.

  - Clarify the intent of related flows, e.g. exit_reason is used for both
    "basic exit reason" and "full exit reason", and it's not always clear
    which of the two is intended without a fair bit of digging.

  - Prepare for future Intel features, e.g. SGX, that add new exit flags
    that are less restricted than FAILED_VMENTRY, i.e. can be set on what
    is otherwise a standard VM-Exit.

Sean Christopherson (10):
  KVM: nVMX: Move reflection check into nested_vmx_reflect_vmexit()
  KVM: nVMX: Drop a superfluous WARN on reflecting EXTERNAL_INTERRUPT
  KVM: nVMX: Pull exit_reason from vcpu_vmx in
    nested_vmx_exit_reflected()
  KVM: VMX: Convert local exit_reason to u16 in
    nested_vmx_exit_reflected()
  KVM: VMX: Convert local exit_reason to u16 in vmx_handle_exit()
  KVM: nVMX: Convert local exit_reason to u16 in
    ...enter_non_root_mode()
  KVM: nVMX: Cast exit_reason to u16 to check for nested
    EXTERNAL_INTERRUPT
  KVM: nVMX: Rename exit_reason to vm_exit_reason for nested VM-Exit
  KVM: VMX: Cache vmx->exit_reason in local u16 in
    vmx_handle_exit_irqoff()
  KVM: VMX: Convert vcpu_vmx.exit_reason to a union

 arch/x86/kvm/vmx/nested.c | 49 +++++++++++++++++++++++----------------
 arch/x86/kvm/vmx/nested.h | 28 ++++++++++++----------
 arch/x86/kvm/vmx/vmx.c    | 39 +++++++++++++++++--------------
 arch/x86/kvm/vmx/vmx.h    | 25 +++++++++++++++++++-
 4 files changed, 90 insertions(+), 51 deletions(-)

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2.24.1