Re: [PATCH 2/3] KVM: VMX: Simplify pdptr and cr3 management

[Sheng Yang <sheng@linux.intel.com>]

On Tuesday 02 June 2009 18:16:14 Avi Kivity wrote:
> Sheng Yang wrote:
> > On Tuesday 02 June 2009 17:46:39 Avi Kivity wrote:
> >> Sheng Yang wrote:
> >>> No, no, not with the new code. For CPU can load pdptrs if EPT enabled
> >>> with PAE from VM exit, there should not be necessary load it
> >>> explicitly. So I estimate the ept_load_pdptr() in exit handler, and put
> >>> it in CR0 handling. Just tried to optimize load-pdptr according to the
> >>> spec, but not got the desired result...
> >>>
> >>> So I am trying to find the failure reason...
> >>
> >> so from your point of view, the patches are okay?
> >
> > Yes. But we should can optimize it more by avoiding most of PDPTR
> > loading, according to the spec.
>
> Patch 3 makes reloading a very rare event.  It only happens on pae mode
> changes or if userspace sets cr3.

Yes, you are right. Quite beautiful. :)

Sorry for misunderstood the meaning of "on demand" without looking at the 
patch carefully...

Looks fine now. Thanks!

BTW: one extra blank line above function kvm_pdptr_read() in patch 3. ;)

-- 
regards
Yang, Sheng