[Qemu-devel] RFH: boot from virtio cdrom?

[Qemu-devel] RFH: boot from virtio cdrom?

[Philipp Hahn]

Hello,

I'm using libvirt to manage my VMs and configured one VM to boot from a CDROM connected via virtio.
This does neither work with QEMU-1.1.2 nor with QEMU-1.5; neither with SeaBIOS is 1.7.0 nor 1.7.2.

/root/qemu-1.5.0+dfsg/qemu-build/x86_64-softmmu/qemu-system-x86_64 \
 -M pc-1.1 \
 -enable-kvm \
 -m 1024 \
 -smp 1,sockets=1,cores=1,threads=1 \
 -name ucs31-64-xxx \
 -uuid 1dae3236-23e8-c87f-ec7b-9f82060fcc72 \
 -nodefconfig -nodefaults \
 -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/ucs31-64-xxx.monitor,server,nowait \
 -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc \
 -no-shutdown \
 -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 \
 -drive file=/var/lib/libvirt/images/ucs31-64-xxx-0.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=unsafe \
 -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0 \
 -drive file=/root/ucs-3.2-0/./virtualization/univention-kvm-virtio/virtio-win-0.1-30.iso,if=none,media=cdrom,id=drive-virtio-disk1,readonly=on,format=raw \
 -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x6,drive=drive-virtio-disk1,id=virtio-disk1,bootindex=1 \
 -device usb-tablet,id=input0 \
 -vga cirrus \
 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5 \
 -sdl

Is this supposed to work or must a bootable CDROM use the ide bus?
I ask because if this is not supposed to work, I need to modify our admin to to prevent CDROMs from being added through virtio by default; later on when Linux is installed, the CDROM works fine through virtio.

Sincerely
Philipp
-- 
Philipp Hahn           Open Source Software Engineer      hahn@univention.de
Univention GmbH        be open.                       fon: +49 421 22 232- 0
Mary-Somerville-Str.1  D-28359 Bremen                 fax: +49 421 22 232-99
                                                   http://www.univention.de/

Re: [Qemu-devel] RFH: boot from virtio cdrom?

[Gerd Hoffmann]

On 06/06/13 17:10, Philipp Hahn wrote:
> Hello,
> 
> I'm using libvirt to manage my VMs and configured one VM to boot from
> a CDROM connected via virtio. This does neither work with QEMU-1.1.2
> nor with QEMU-1.5; neither with SeaBIOS is 1.7.0 nor 1.7.2.

Doesn't work with virtio-blk, virtio-scsi can handle that just fine though.

cheers,
  Gerd

Re: [Qemu-devel] RFH: boot from virtio cdrom?

[Laszlo Ersek]

On 06/07/13 08:12, Gerd Hoffmann wrote:
> On 06/06/13 17:10, Philipp Hahn wrote:
>> Hello,
>>
>> I'm using libvirt to manage my VMs and configured one VM to boot from
>> a CDROM connected via virtio. This does neither work with QEMU-1.1.2
>> nor with QEMU-1.5; neither with SeaBIOS is 1.7.0 nor 1.7.2.
> 
> Doesn't work with virtio-blk, virtio-scsi can handle that just fine though.

... just make sure your installer media has immediate support for
virtio-scsi (or, in case of Windows, at least access to a driver disk,
but "virtio-win-0.1-30.iso" in your command line implied that). Example:
<https://bugzilla.redhat.com/show_bug.cgi?id=864012>.

Laszlo

Re: [Qemu-devel] RFH: boot from virtio cdrom?

[Paolo Bonzini]

Il 07/06/2013 03:02, Laszlo Ersek ha scritto:
>>> >> I'm using libvirt to manage my VMs and configured one VM to boot from
>>> >> a CDROM connected via virtio. This does neither work with QEMU-1.1.2
>>> >> nor with QEMU-1.5; neither with SeaBIOS is 1.7.0 nor 1.7.2.
>> > 
>> > Doesn't work with virtio-blk, virtio-scsi can handle that just fine though.
> ... just make sure your installer media has immediate support for
> virtio-scsi (or, in case of Windows, at least access to a driver disk,
> but "virtio-win-0.1-30.iso" in your command line implied that). Example:
> <https://bugzilla.redhat.com/show_bug.cgi?id=864012>.

... and that driver disk probably should be on an IDE drive, otherwise
you have a chicken-and-egg problem (you need the drivers to load the
drivers).

Paolo