Re: [PATCH] libxc: Add xc_domain_hvm_get_mtrr_type() call

[Razvan Cojocaru <rzvncj@gmail.com>]

>> I did manage to take 'enabled' into account with what appears to be
>> success, but if I've read the situation correctly, there's not much to
>> do about 'overlap', unless we save it in hvm_save_mtrr_msr() like it's
>> done with 'enabled'. What do you think?
>
> It's not an architectural thing so I don't think it belongs in there.
>
> TBH until someone figures out or explains what overlap actually is I
> don't know if it even needs exporting or taking into account in
> userspace.

Well, get_mtrr_range() is being called by is_var_mtrr_overlapped(), 
which is the function that sets m->overlapped, which is then used quite 
a lot in the logic of the get_mtrr_type(), which this patch attempts to 
bring into userspace via libxc.

I would quite happily discount all checks against the overlap boolean 
argument (and my code seems to work like that), but I suspect whoever 
wrote get_mtrr_type() had good reason to check for that.

Thanks,
Razvan Cojocaru