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

[Avi Kivity <avi@redhat.com>]

On 05/20/2011 02:57 PM, Gleb Natapov wrote:
> On Fri, May 20, 2011 at 11:59:58AM +0300, Avi Kivity wrote:
> >  On 05/19/2011 07:27 PM, Gleb Natapov wrote:
> >  >>   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.
> >  >>
> >  >I do not think that window manager is a good analogy. Window can
> >  >overlap with only its siblings. In our memory tree each final node may
> >  >overlap with any other node in the tree.
> >  >
> >
> >  Transparent windows.
> >
> No, still not that. Think about child windows that resides outside of its
> parent windows on screen. In our memory region terms think about PCI BAR
> is registered to overlap with RAM at address 0x1000 for instance. PCI
> BAR memory region and RAM memory region are on very different branches
> of the global tree.

Right.  But what's the problem with that?

Which one takes precedence is determined by the priorities of the RAM 
subregion vs. the PCI bus subregion.

-- 
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