Re: [edk2] Passing Xen memory map and resource map to OVMF

From: Wei Liu <wei.liu2@citrix.com>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: Wei Liu <wei.liu2@citrix.com>,
	"Jordan Justen (Intel address)" <jordan.l.justen@intel.com>,
	edk2-devel@lists.sourceforge.net, xen-devel@lists.xen.org,
	Igor Mammedov <imammedo@redhat.com>,
	Laszlo Ersek <lersek@redhat.com>
Subject: Re: [edk2] Passing Xen memory map and resource map to OVMF
Date: Wed, 13 Nov 2013 14:06:54 +0000	[thread overview]
Message-ID: <20131113140654.GF4948__19832.5096200735$1384351712$gmane$org@zion.uk.xensource.com> (raw)
In-Reply-To: <1384350814.3560.24.camel@nilsson.home.kraxel.org>

On Wed, Nov 13, 2013 at 02:53:34PM +0100, Gerd Hoffmann wrote:
> On Mi, 2013-11-13 at 11:58 +0000, Wei Liu wrote:
> > On Wed, Nov 13, 2013 at 08:03:39AM +0100, Gerd Hoffmann wrote:
> > >   Hi,
> > > 
> > > > > The first thing that comes in mind is to reuse E820 table for memory map
> > > > > plus some extra fields for io / mmio resources. But I guess UEFI is the
> > > > > new world so stuffs like E820 from old world will be less popular. Any
> > > > > suggestion on existing table / data structure I can use?
> > > 
> > > What io/mmio ressources do you need to pass on?
> > > 
> > 
> > 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. OVMF
should just use whatever it gets.

> 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.

Wei.

> cheers,
>   Gerd
> 
> 