[0/2] KVM: VMX: Sanitize VM-Entry/VM-Exit pairs during setup

Message

Sean Christopherson May 25, 2022, 9:04 p.m. UTC

Sanitize the VM-Entry/VM-Exit load+load and load+clear pairs when kvm_intel
is loaded instead of checking both controls at runtime.  Not sanitizing
means KVM ends up setting non-dynamic bits in the VMCS.

Add an opt-in knob to force kvm_intel to bail if an inconsistent pair is
detected instead of using a degraded and/or potentially broken setup.

Arguably patch 01 is stable material, but my mental coin flip came up
negative and I didn't Cc: stable.

And for patch 02, I'd definitely be favor of making it opt-out instead of
opt-in, but there's a non-zero chance that someone out there is running
KVM in a misconfigured VM...

Sean Christopherson (2):
  KVM: VMX: Sanitize VM-Entry/VM-Exit control pairs at kvm_intel load
    time
  KVM: VMX: Add knob to allow rejecting kvm_intel on inconsistent VMCS
    config

 arch/x86/kvm/vmx/capabilities.h | 13 +++-----
 arch/x86/kvm/vmx/vmx.c          | 55 +++++++++++++++++++++++++++++++--
 2 files changed, 56 insertions(+), 12 deletions(-)


base-commit: 90bde5bea810d766e7046bf5884f2ccf76dd78e9