Re: [PATCH][v2] Hybrid extension support in Xen

[Sheng Yang <sheng@linux.intel.com>]

On Tuesday 02 February 2010 22:01:43 Keir Fraser wrote:
> On 02/02/2010 13:52, "Sheng Yang" <sheng@linux.intel.com> wrote:
> >> I didn't even find where these get used, except to reserve an area in
> >> e820, and it wasn't clear why that reservation is necessary.
> >
> > It has been used in the last [6/6] patch of Linux kernel side, which
> > would use the pages to map grant table. It works the same as the MMIO
> > region in PVonHVM device. Reserve it in BIOS because we think it's more
> > elegant than depends on QEmu to provide the reserved memory space.
> 
> Hmm. Can't this be done in phases? It seems unnecessary to be making
>  changes solely to remove qemu dependencies in the intial patchset, when
>  the patchset does not actually achieve that aim.
> 
> I think an HVM guest with no PCI space is a little way off, and perhaps we
> can find a better way than hardcoding an address in two places.

Sure. I would try stick to old QEmu provided MMIO first. (Maybe try Ian 
Campbell's advice to get some more flexible ones later).

-- 
regards
Yang, Sheng