Re: [PATCH] Paging and memory sharing for HVM guests

[Patrick Colp <pjcolp@cs.ubc.ca>]

Jan Beulich wrote:
>>>> Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 17.12.09 17:38 >>>
>> 1). The  "*mfnp |= 0x80000000U;" and "*mfnp |= 0xf0000000U;" should
>>    use a #define. Maybe copy over the #defines from the xen tree ?
> 
> Did you find any defines in the tools sources for that? The only place I
> found this condition being checked at all was in xc_map_foreign_pages(),
> where it used hard-coded values. Or are you referring to the
> XEN_DOMCTL_PFINFO_* values? I'd say they're being mis-used when
> applied to the mfn array used by mmap-batch (including apparent
> pre-existing uses).

I think many people agree that this idea of using 0xf0000000 is a very 
inelegant solution (myself included). Maybe now would be a good time to 
hash out what the proper way to deal with this is. I think this discussion 
should extend to the privcmd/libxc mmap interfaces generally as well.


Patrick