seabios should have native scsi support

[Scott Moser]

Binary package hint: seabios

Currently when a grub multiboot image is booted with 'kvm -kernel' and 'biosdisk' module, it will see block devices of type IDE or virtio. It will not see scsi devices.

To demonstrate this:
$ qemu-img create -f qcow2 disk.img 1G
$ grub-mkrescue --output=rescue.iso
$ grub-mkimage -O i386-pc --output=grub-mb.img biosdisk minicmd part_msdos

An 'ls' inside the grub prompt will show hard disks (hd0) on if:
a.) -drive uses interface of virtio or scsi
or
b.) kvm boots boot from a cdrom or floppy

For example, with these commands, grub will see a '(hd0)'
$ kvm -drive file=disk.img,if=scsi,boot=on -cdrom rescue.iso -boot d
$ kvm -drive file=disk.img,if=scsi,boot=on -floppy rescue.iso -boot a
$ kvm -drive file=disk.img,if=virtio,boot=on -cdrom rescue.iso -boot d
$ kvm -drive file=disk.img,if=ide,boot=on -cdrom rescue.iso -boot d
$ kvm -drive file=disk.img,if=virtio,boot=on -kernel grub-mb.img
$ kvm -drive file=disk.img,if=ide,boot=on -kernel grub-mb.img

But the following will not:
$ kvm -drive file=disk.img,if=scsi,boot=on -kernel grub-mb.img

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: seabios 0.6.0-0ubuntu1
ProcVersionSignature: User Name 2.6.32-305.9-ec2 2.6.32.11+drm33.2
Uname: Linux 2.6.32-305-ec2 i686
Architecture: i386
Date: Thu Jul 29 03:21:21 2010
Dependencies:

Ec2AMI: ami-e930db80
Ec2AMIManifest: ubuntu-images-testing-us/ubuntu-maverick-daily-i386-server-20100727.manifest.xml
Ec2AvailabilityZone: us-east-1b
Ec2InstanceType: m1.small
Ec2Kernel: aki-407d9529
Ec2Ramdisk: unavailable
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: seabios

[Scott Moser (smoser)]

I'm fully aware that this isn't a high priority bug for anyone primarily due to the fact that it uses the word 'scsi'.
However, I wanted to document it here.

Also, I'm attaching an IRC log of a conversation with aligouri in #kvm discussing the issue.

[Scott Moser (smoser)]

Just on other thought, grub *does* have a 'scsi' module, that in theory could handle identifying scsi disks outside of 'biosdisk'. However, it doesn't work now.

[agraf (agraf)]

I guess the best way to make this work would be to get the original option rom for the emulated LSI SCSI controller licensed so that we can use it freely. That way we

a) verify that the emulation is correct
b) are even closer to real world hardware

The difficult thing here is on how to talk to LSI.

[Scott Moser (smoser)]

Just a comment, the commands in the summary will boot the first time, but a reboot will (possibly) fail. bug 615529 has more info on that.

[Serge Hallyn (serge-hallyn)]

(Clearly this must be done upstream first, so marking Triaged for the Ubuntu
task)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Michael Tokarev (mjt+launchpad-tls)]

FWIW, this is implemented and works in seabios 0.7.1

[Scott Moser (smoser)]

I just did some bug cleanup work here.
  Per Michael's comment, this is now fixed in seabios. So I marked the seabios task as fix-released in Ubuntu.
  12.04 will not have this fix present, as its seabios is 0.6.2, but versions of ubuntu 12.10 (quantal) and later should be fix-released.

Note, I did not test this.