Re: [Qemu-devel] [RFC] Memory API

[Anthony Liguori]

On 05/19/2011 09:40 AM, Avi Kivity wrote:
> On 05/19/2011 05:37 PM, Anthony Liguori wrote:
> > So.... do you do:
> >
> > isa_register_region(ISABus *bus, MemoryRegion *mr, int priority)
> > {
> > chipset_register_region(bus->chipset, mr, priority + 1);
> > }
> >
> > I don't really understand how you can fold everything into one table
> > and not allow devices to override their parents using priorities.
>
> Think of how a window manager folds windows with priorities onto a flat
> framebuffer.
>
> You do a depth-first walk of the tree. For each child list, you iterate
> it from the lowest to highest priority, allowing later subregions
> override earlier subregions.

Okay, but this doesn't explain how you'll let RAM override the VGA 
mapping since RAM is not represented in the same child list as VGA (RAM 
is a child of the PMC whereas VGA is a child of ISA/PCI, both of which 
are at least one level removed from the PMC).

Regards,

Anthony Liguori