Re: [Qemu-devel] Anyone seeing huge slowdown launching qemu with Linux 2.6.35?

[Alexander Graf]

On 04.08.2010, at 19:36, Anthony Liguori wrote:

> On 08/04/2010 12:31 PM, Alexander Graf wrote:
>> On 04.08.2010, at 19:26, Anthony Liguori wrote:
>> 
>>   
>>> On 08/04/2010 11:45 AM, Alexander Graf wrote:
>>>     
>>>> Frankly, I partially agreed to your point when we were talking about 300ms 
>>>> vs. 2 seconds. Now that we're talking 8 seconds that whole point is moot. 
>>>> We chose the wrong interface to transfer kernel+initrd data into the guest.
>>>> 
>>>> Now the question is how to fix that. I would veto against anything 
>>>> normally guest-OS-visible. By occupying the floppy, you lose a floppy 
>>>> drive in the guest. By occupying a disk, you see an unwanted disk in the 
>>>> guest.
>>>>       
>>> 
>>> Introduce a new virtio device type (say, id 6).  Teach SeaBIOS that 6 is 
>>> exactly like virtio-blk (id 2).  Make it clear that id 6 is only to be used 
>>> by firmware and that normal guest drivers should not be written for id 6.
>>>     
>> Why not make id 6 be a fw_cfg virtio interface?
> 
> Because that's a ton more work and we need fw_cfg to be available before PCI 
> is.  IOW, fw_cfg cannot be a PCI interface.

in addition to fw_cfg. So you'd have the same contents be exposed using both 
interfaces.

Alex