Re: [PATCH 2/4] KVM: nVMX: remove unnecessary code in prepare_vmcs02

[Paolo Bonzini <pbonzini@redhat.com>]

On 5/28/26 02:14, Sean Christopherson wrote:
> Hah!  Fixing your own mistakes, but making it look like it was my fault.  :-D
> 
> In the original version[1] of what ended up being commit c7554efc8335 ("KVM: nVMX:
> Copy PDPTRs to/from vmcs12 only when necessary"), the writes in what is now
> prepare_vmcs02_rare() (and I at least am still amused by the meat pun[2]) were
> removed.  When the mega-collection of optimizations was posted[3], the removal
> of that code got dropped.
> 
> AFAICT, it was completely unintenional.  Maybe a rebase goof?

Yes, probably.

> I don't care terribly about the performance, and I 100% agree the extra complexity
> to do the "late" loading is ugly, but I still think I'd prefer to keep the "late"
> loading so that there's symmetry with the vmcs02 => vmcs12 sync, and so that we
> don't try to optimize the prepare_vmcs02_rare() code and consume incorrect state
> via is_pae_paging().
> 
> Alternatively, expand the comment in prepare_vmcs02_rare()?

Ok, I will keep the late loading.

Paolo