Re: [Qemu-devel] [PATCH - V3] Port codes from qemu-kvm to support booting from SCSI disk image

[Alexander Graf]

On 18.08.2010, at 17:08, Paul Brook wrote:

>> The qemu-kvm could boot from SCSI disk image by utilizing seabios, this
>> patch ported codes
>> from qemu-kvm to let upstream qemu to support booting from SCSI disk image.
> 
> No. This has nothing to do with SCSI.
> 
> What it does is add a really cheap and nasty block storage device that 
> aliases 
> one of the other block devices in the system. This is bad. The OS has no way 
> of knowing which devices are aliased, and we really don't want yet another 
> braindead guest visible interface (c.f. recent performance issues where -
> kernel/fw_cfg were being abused)
> 
> This has been discussed several times before. The proper solution is to teach 
> the bios how to boot off SCSI devices. IIRC support for virtio devices 
> already 
> exists, implementing support for the SCSI controller shouldn't be that much 
> harder.

Couldn't we just have an option rom for the SCSI controller? The same way the 
VGABIOS is a rewrite of a VGA BIOS for the Cirrus Logic...


Alex