On 05/20/2011 04:01 AM, Avi Kivity wrote:
On 05/19/2011 07:32 PM, Anthony Liguori 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.
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).
VGA will override RAM.
Memory controller
|
+-- RAM container (prio 0)
|
+-- PCI container (prio 1)
|
+--- vga window
Unless the RAM controller increases it's priority, right? That's how
you would implement SMM, by doing priority++?
But if you have:
Memory controller
|
+-- RAM container (prio 0)
|
+-- PCI container (prio 1)
|
+-- PCI-X container (prio 2)
|
+--- vga window
Now you need to do priority = 3?
Jan had mentioned previously about registering a new temporary window.
I assume the registration always gets highest_priority++, or do you have
to explicitly specify that PCI container gets priority=1?
Regards,
Anthony Liguori