Re: [PATCH v2 6/6] KVM: nVMX: optimize prepare_vmcs02{,_full} for Enlightened VMCS case

[Paolo Bonzini]

On 25/07/2018 15:26, Vitaly Kuznetsov wrote:
> Doing it in nested_vmx_handle_enlightened_vmptrld() is even better: we
> can simplify copy_enlightened_to_vmcs12() too!

Yes, that's true!

> The other place where we set dirty_vmcs12 is the newly introduced
> vmx_set_nested_state() but I think I'm going to add support for eVMCS
> there later and just return something like -ENOTSUPP for now. Too many
> people work on nested simultaneously :-)

Hmm, I think that means you have to put the clean fields in the
vmx_nested struct.  Then it's really easy in vmx_set_nested_state to
clear all the clean bits.  Touching memory in vmx_set_nested_state is...
*puts on sunglasses* a touchy subject (see comment in kvm/queue's
enter_vmx_non_root_mode).

Thanks,

Paolo