Re: [PATCH 3/4] KVM: MMU: reduce the size of mmu_page_path

[Xiao Guangrong]

On 03/25/2016 09:45 PM, Paolo Bonzini wrote:
> On 25/03/2016 14:19, Xiao Guangrong wrote:
> > Currently only PT64_ROOT_LEVEL - 1 levels are used, one additional entry
> > in .parent[] is used as a sentinel, the additional entry in .idx[] is
> > purely wasted
> >
> > This patch reduces its size and sets the sentinel on the upper level of
> > the place where we start from
>
> This patch and the previous one are basically redoing commit
> 0a47cd85833e ("KVM: MMU: Fix ubsan warnings", 2016-03-04).  While you
> find your version easier to understand, I of course find mine easier.
>
> Rather than getting stuck in a ko fight, the solution is to stick with
> the code in KVM and add comments.  I'll give it a try...

If you do not like this one, we can just make the .index is
[PT64_ROOT_LEVEL - 1] and keep the sentinel in .parents[], that little
change and nice code shape.