Re: [V3 PATCH 7/9] x86/hvm: pkeys, add pkeys support for guest_walk_tables

["Han, Huaitong" <huaitong.han@intel.com>]

On Thu, 2015-12-10 at 18:59 +0000, Andrew Cooper wrote:
> On 07/12/15 09:16, Huaitong Han wrote:
> > +
> > +    /* PKRU dom0 is always zero */
> > +    if ( likely(!pte_pkeys) )
> > +        return 0;
> 
> This is not an architectural restriction (as far as I can tell).  Xen
> must never make assumptions about how a guest chooses to use a
> feature.
Yes, I will remove the code section.

On my test machine, writing non-zero value to PKRU domain 0 will lead
to a GP fault, this is also conform to the usage scenario, and I will
ask the intel architect the reason why SDM does not describe.

If it is OK, I will send the other patch or new version patch to
improve the efficiency of the code.
> 
> ~Andrew