Xen devel - Nov 2013 - Re: [edk2] Passing Xen memory map and resource map to OVMF

Hi,
> > > MMIO holes, IO range created by hvmloader.
> > 
> > Why?  All (memory) address space not backed by ram effectively is
mmio.
> > There is no need to explicitly declare holes ...
> > 
> 
> Yes there is, because hvmloader is in charge of declaring holes.
Why does it declare holes in the first place?
Just for ACPI _CRS?  Or other reasons too?
> OVMF
> should just use whatever it gets.
What would OVMF use them for?

As far I know hvmloader creates the acpi tables and initializes pci
device mappings, so there isn''t much to manage for ovmf ...
> > Also why io ranges?  Isn''t pc io address space pretty much
fixed anyway?
> > 
> 
> This is not actually necessary, but I want to pass this anyway, just to
> be consistent.
I don''t see the point in passing it ...

cheers,
  Gerd