Re: [PATCH V13 1/7] xen/arm: p2m changes for mem_access support

[Ian Campbell <ian.campbell@citrix.com>]

On Fri, 2015-03-06 at 22:24 +0100, Tamas K Lengyel wrote:
> Add necessary changes for page table construction routines to pass
> the default access information.

You do more than just plumb through the access information variable
thoguh. You seem to setup preemption support, add some tother
needed-by-generic-code infrastructure functions and data fields too etc.

The actual code changes seem OK to me, assuming I have inferred your
intention correctly. But please could you expand on this sentence to
describe the full scope/intention of the changes.

>  We store the p2m_access_t info in a
> Radix tree as the PTE lacks enough software programmable bits.

I think here you just setup the radix tree which will eventually be used
to do this, at least I can't see the actual store, nor any lookups.
Assuming that is what was intended please indicate that here.

It's possible that some of these changes would have been clearer done as
individual patches later on, or part of a later patch which actually
uses things. We're at v13 though so I'll leave that for you to decide.