Priority was used to make visible some subregions by obscuring the parent MemoryRegion addresses overlapping with the subregion.
By allowing the priority to be negative the opposite can be done: Allow a subregion to be visible on all the addresses not covered by other subregions. Signed-off-by: Marcel Apfelbaum <marce...@redhat.com> --- docs/memory.txt | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/docs/memory.txt b/docs/memory.txt index feb9fe9..174c0d7 100644 --- a/docs/memory.txt +++ b/docs/memory.txt @@ -80,6 +80,10 @@ guest. This is done with memory_region_add_subregion_overlap(), which allows the region to overlap any other region in the same container, and specifies a priority that allows the core to decide which of two regions at the same address are visible (highest wins). +Priority values are signed, and the default value is zero. This means that +you can use memory_region_add_subregion_overlap() both to specify a region +that must sit 'above' any others (with a positive priority) and also a +background region that sits 'below' others (with a negative priority). Visibility ---------- -- 1.8.3.1
