[Qemu-devel] Re: [PATCH] hpet: Clean up initial hpet counter

[Gleb Natapov <gleb@redhat.com>]

On Wed, Jun 16, 2010 at 09:51:14AM +0200, Jan Kiszka wrote:
> Gleb Natapov wrote:
> > On Wed, Jun 16, 2010 at 09:03:01AM +0200, Jan Kiszka wrote:
> >> Gleb Natapov wrote:
> >>> On Wed, Jun 16, 2010 at 12:40:28AM +0200, Jan Kiszka wrote:
> >>>> From: Jan Kiszka <jan.kiszka@siemens.com>
> >>>>
> >>>> There is no need starting with the special value for hpet_cfg.count.
> >>>> Either Seabios is aware of the new firmware interface and properly
> >>>> interprets the counter or it simply ignores it anyway.
> >>>>
> >>> I want seabios to be able to distinguish between old qemu and new one.
> >> I see now. But isn't it a good chance to introduce a proper generic
> >> interface for exploring supported fw-cfg keys?
> >>
> > Having such interface would be nice. Pity we haven't introduced it from
> > the start. If we do it now seabios will have to find out somehow that
> > qemu support such interface. Chicken and egg ;)
> 
> That is easy: Add a key the describes the highest supported key value
> (looks like this is monotonously increasing). Older qemu versions will
> return 0.
> 
That will not support holes in key space, and our key space is already
sparse.

--
			Gleb.