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(-)
--
2.34.1
