Re: [PATCH v2 3/7] KVM: nVMX: Ignore 'hv_clean_fields' data when eVMCS data is copied in vmx_get_nested_state()

From: Vitaly Kuznetsov
Date: Mon May 24 2021 - 10:12:51 EST


Paolo Bonzini <pbonzini@xxxxxxxxxx> writes:

> On 17/05/21 15:50, Vitaly Kuznetsov wrote:
>> 'Clean fields' data from enlightened VMCS is only valid upon vmentry: L1
>> hypervisor is not obliged to keep it up-to-date while it is mangling L2's
>> state, KVM_GET_NESTED_STATE request may come at a wrong moment when actual
>> eVMCS changes are unsynchronized with 'hv_clean_fields'. As upon migration
>> VMCS12 is used as a source of ultimate truth, we must make sure we pick all
>> the changes to eVMCS and thus 'clean fields' data must be ignored.
>
> While you're at it, would you mind making copy_vmcs12_to_enlightened and
> copy_enlightened_to_vmcs12 void?
>

Sure, no problem.

--
Vitaly