Re: [Qemu-devel] [PATCH 0/2] extboot reloaded.

[Paul Brook]

On Tuesday 17 November 2009, Gerd Hoffmann wrote:
> On 11/17/09 13:36, Paul Brook wrote:
> >>> In fact I'd much prefer to see extboot rewritten to just virtio-block.
> >>
> >> Hmm, I'd prefer something which is *not* used by the guest OS, so it is
> >> a pure bootloader thing.  When using it to boot from scsi you don't want
> >> to have the disk show up twice (as virtio and scsi) in the guest.
> >
> > You're assuming noone ever writes OS support for extboot...
> 
> Which would be almost as silly as writing OS support for bios-int13 ...

Not entirely. int13 is a software interface, extboot is a hardware interface.
Look at it the other way round: If I already have my low performance boot 
device exposed via extboot (on an otherwise diskless client), why should I 
have to also expose it via virtio-blk just so that the guest can access it for 
installing kernel upgrades.

Paul