Re: [Qemu-devel] [PATCH 0/2] port over extboot from kvm

[Hannes Reinecke <hare@suse.de>]

Anthony Liguori wrote:
> Gerd Hoffmann wrote:
>> On 11/09/09 17:06, Paul Brook wrote:
>>> On Tuesday 08 September 2009, Anthony Liguori wrote:
>>>> Gerd Hoffmann wrote:
>>>>> $subject says pretty much everything.
>>>>>
>>>>> extboot.[cS] are a straight copy from the kvm tree.  The windup in
>>>>> vl,c
>>>>> and hw/pc.c is done slightly different, I've added a function to
>>>>> lookup
>>>>> the boot drive instead of adding a new global variable.
>>>>
>>>> I think the function here is high even if the implementation is ugly.
>>>> In the past, Paul strongly objected to this.  Paul, care to comment?
>>>
>>> Doesn't gpxe support virtio-blk, without requiring any additional qemu
>>> "features"?
>>
>> As far I know patches exist but where never merged.
>> Also there is no way to boot from scsi+usb ...
> 
> I think Kevin mentioned he would likely to usb boot support for
> SeaBIOS.  Adding virtio-blk support to SeaBIOS would also be pretty
> reasonable.
> 
> SCSI is a bit more tough.  Doing an LSI driver in SeaBIOS would be a bit
> tougher.
> 
But why? Why do we have to emulate the entire HBA for the BIOS?
The HBA is emulated, too, and just uses the bdrv interface
internally anyway.
So IMHO it makes far more sense to skip the HBA emulation in
the BIOS completely and just use the bdrv interface directly
here.

Where is the drawback?
(Apart from the missing BIOS initialization of the HBA?)

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
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