Re: [Qemu-devel] [SeaBIOS] [PATCH 4/6] Mapping of BARs and Bridge regions

[Gerd Hoffmann]

On 03/01/12 07:57, Alexey Korolev wrote:
> In pci_bios_map_regions() we try to reserve memory for 
> all entries of root bus regions.
> If pci_bios_init_root_regions() fails - e.g no enough space, we create two 
> new pci_regions:
> r64pref, r64mem and migrate all entries which are 64bit capable to them. 
> Migration process
> is very simple: delete the entry from one list add to another.

It isn't that simple.  There are a bunch of constrains.  First the
bridge must be 64bit capable.  All bridges up to the root bus in case of
nested bridges.  Second all other prefmem bars of devices behind the
bridge must be 64bit capable too.  Again, in case of nested bridges this
applies to all devices behind the toplevel bridge.

cheers,
  Gerd