[PATCH v3 0/5] KVM: nVMX: Fix Windows 11 + WSL2 + Enlightened VMCS

[Vitaly Kuznetsov]

Changes since v2 [Sean]:
- Tweak a comment in PATCH5.
- Add Reviewed-by: tags to PATCHes 3 and 5.

Original description:

Windows 11 with enabled Hyper-V role doesn't boot on KVM when Enlightened
VMCS interface is provided to it. The observed behavior doesn't conform to
Hyper-V TLFS. In particular, I'm observing 'VMREAD' instructions trying to
access field 0x4404 ("VM-exit interruption information"). TLFS, however, is
very clear this should not be happening:

"Any VMREAD or VMWRITE instructions while an enlightened VMCS is active is
unsupported and can result in unexpected behavior."

Microsoft confirms this is a bug in Hyper-V which is supposed to get fixed
eventually. For the time being, implement a workaround in KVM allowing 
VMREAD instructions to read from the currently loaded Enlightened VMCS.

Patches 1-2 are unrelated fixes to VMX feature MSR filtering when eVMCS is
enabled. Patches 3 and 4 are preparatory changes, patch 5 implements the
workaround.

Vitaly Kuznetsov (5):
  KVM: nVMX: Also filter MSR_IA32_VMX_TRUE_PINBASED_CTLS when eVMCS
  KVM: nVMX: eVMCS: Filter out VM_EXIT_SAVE_VMX_PREEMPTION_TIMER
  KVM: nVMX: Rename vmcs_to_field_offset{,_table}
  KVM: nVMX: Implement evmcs_field_offset() suitable for handle_vmread()
  KVM: nVMX: Allow VMREAD when Enlightened VMCS is in use

 arch/x86/kvm/vmx/evmcs.c  |  4 +--
 arch/x86/kvm/vmx/evmcs.h  | 48 +++++++++++++++++++++++++------
 arch/x86/kvm/vmx/nested.c | 59 +++++++++++++++++++++++++++------------
 arch/x86/kvm/vmx/vmcs12.c |  4 +--
 arch/x86/kvm/vmx/vmcs12.h |  6 ++--
 5 files changed, 87 insertions(+), 34 deletions(-)

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2.34.1