[Qemu-devel] Re: [SeaBIOS] [PATCHv2] load hpet info for HPET ACPI table from qemu

[Gleb Natapov]

On Tue, Jun 15, 2010 at 07:47:55AM +0300, Avi Kivity wrote:
> On 06/14/2010 10:38 PM, Anthony Liguori wrote:
> >
> >I think we can be pretty flexible as long as we're careful about
> >releases.  For instance, I've applied Gleb's current patch but
> >won't update SeaBIOS until the interface is worked out.  If we
> >decide to implement a new interface, there's no harm since we've
> >never had a qemu build that had a combination of SeaBIOS and
> >fw_cfg that didn't work.
> 
> Or we can choose a new interface number if the interface changes.
> 
> One of Kevin's points was that the ACPI tables are a documented
> interface.  AFAIR, the firmware configuration interface isn't.  We
> need to start documenting it (and reject patches without
> accompanying documentation).
> 
ACPI tables are, indeed, documented interface (it doesn't make it good
interface though :)), but it is interface between firmware and OS, so
it may (and it does) have things like "if firmware support that, then
this bit should be set". Using it as interface to describe HW to
firmware is just plain abuse.

--
                        Gleb.