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

[Anthony Liguori <anthony@codemonkey.ws>]

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.
>
>