lkml.org 
[lkml]   [2022]   [Jan]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH v2 0/5] KVM: nVMX: Fix Windows 11 + WSL2 + Enlightened VMCS
Date
Changes since v1 [Sean]:
- Rename vmcs12_field_offset_table -> vmcs12_field_offsets,
vmcs12_field_offset()->get_vmcs12_field_offset()
- Forbid VMREAD when "current_vmptr == INVALID_GPA && evmptr_is_valid() &&
is_guest_mode()".

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(-)

--
2.33.1

\
 
 \ /
  Last update: 2022-01-07 11:30    [W:1.510 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site