Re: [Qemu-devel] [PATCH RFC] memory: drop _overlap variant

[Peter Maydell]

On 14 February 2013 12:45, Michael S. Tsirkin <address@hidden> wrote:
> overlap flag in the region is currently unused, most devices have no
> idea whether their region overlaps with anything, so drop it,
> assume that all regions can overlap and always require priority.

Devices themselves shouldn't care, for the most part -- they just
provide a memory region and it's their parent that has to map it
and know whether it overlaps or not. Similarly, parents should
generally be in control of the container they're mapping the
memory region into, and know whether it will be an overlapping
map or not.

> It's also not clear how should devices allocate priorities.

Up to the parent which controls the region being mapped into.
I definitely don't like making the priority argument mandatory:
this is just introducing pointless boilerplate for the common
case where nothing overlaps and you know nothing overlaps.

Maybe we should take the printf() about subregion collisions
in memory_region_add_subregion_common() out of the #if 0
that it currently sits in?

-- PMM