From: Maxim Levitsky mlevitsk@redhat.com
commit d51e1d3f6b4236e0352407d8a63f5c5f71ce193d upstream.
Even when we are outside the nested guest, some vmcs02 fields may not be in sync vs vmcs12. This is intentional, even across nested VM-exit, because the sync can be delayed until the nested hypervisor performs a VMCLEAR or a VMREAD/VMWRITE that affects those rarely accessed fields.
However, during KVM_GET_NESTED_STATE, the vmcs12 has to be up to date to be able to restore it. To fix that, call copy_vmcs02_to_vmcs12_rare() before the vmcs12 contents are copied to userspace.
Fixes: 7952d769c29ca ("KVM: nVMX: Sync rarely accessed guest fields only when needed") Reviewed-by: Sean Christopherson seanjc@google.com Signed-off-by: Maxim Levitsky mlevitsk@redhat.com Message-Id: 20210114205449.8715-2-mlevitsk@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kvm/vmx/nested.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
--- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5579,11 +5579,14 @@ static int vmx_get_nested_state(struct k if (is_guest_mode(vcpu)) { sync_vmcs02_to_vmcs12(vcpu, vmcs12); sync_vmcs02_to_vmcs12_rare(vcpu, vmcs12); - } else if (!vmx->nested.need_vmcs12_to_shadow_sync) { - if (vmx->nested.hv_evmcs) - copy_enlightened_to_vmcs12(vmx); - else if (enable_shadow_vmcs) - copy_shadow_to_vmcs12(vmx); + } else { + copy_vmcs02_to_vmcs12_rare(vcpu, get_vmcs12(vcpu)); + if (!vmx->nested.need_vmcs12_to_shadow_sync) { + if (vmx->nested.hv_evmcs) + copy_enlightened_to_vmcs12(vmx); + else if (enable_shadow_vmcs) + copy_shadow_to_vmcs12(vmx); + } }
BUILD_BUG_ON(sizeof(user_vmx_nested_state->vmcs12) < VMCS12_SIZE);