Messages in this thread | ![/](/images/icornerl.gif) | | From | Vitaly Kuznetsov <> | Subject | [PATCH 0/5] KVM: nVMX: Fix Windows 11 + WSL2 + Enlightened VMCS | Date | Tue, 14 Dec 2021 15:38:54 +0100 |
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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} to vmcs12_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 | 42 ++++++++++++++++++++++++---------- arch/x86/kvm/vmx/vmcs12.c | 4 ++-- arch/x86/kvm/vmx/vmcs12.h | 6 ++--- 5 files changed, 76 insertions(+), 28 deletions(-)
-- 2.33.1
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