Re: [Qemu-devel] Question about qemu firmware configuration (fw_cfg) device

[Anthony Liguori]

On 07/19/2010 04:15 AM, Gleb Natapov wrote:
> On Mon, Jul 19, 2010 at 11:09:13AM +0200, Alexander Graf wrote:
>    
> > On 19.07.2010, at 11:06, Gleb Natapov wrote:
> >
> >      
> > > On Mon, Jul 19, 2010 at 10:00:04AM +0100, Richard W.M. Jones wrote:
> > >        
> > > > virt-install is another program that uses explicit -initrd.
> > > >
> > > >          
> > > Installation takes a lot of time. Saving 1 second there will not be
> > > noticeable. And during lifetime of installed VM initrd will be loaded
> > > from its disk.
> > >        
> > Guys, please. It shouldn't be one or the other. Let's make sure both ways of 
> > doing things are fast. That's what users want: fast.
> >
> >      
> That what we are talking about, no? We are trying to find faster way to
> load kernel/initrd and stay architectural.

Modern platforms are not nearly as "architectural" as you would think.

It's not unusual to hang a custom chip off of the Southbridge that 
implements platform specific services along with an array of "legacy" 
devices that are implemented mostly in software to cost.

Other buses (like PS/2) are largely implemented in SMM today by the BIOS.

Regards,

Anthony Liguori

>   Honestly I would expect much
> greater speedup from Richard's approach like 2 seconds vs 8 seconds. It
> is hard to justify code complication just for 1 second speedup.
>
> --
>                         Gleb.
>
>