[libvirt] Rudimentary (basic) s390x architecture functions for libvirt

[Patrick Siegl]

Thanks for the good advice regarding the 'qemu monitor' and starting
virtual machines with 'cont' on this monitor.
Thank telnet, virtual machines can start with param '-S' on s390x. :-)

In the 'qemu_command.c' I had commented out so much because you build a
virtual machine with the PCI-Bus.
But on s390x there ist only the s390-virtio - Bus which you can only
activate but can't properly configure.

I will try  to correct my last patch within the next days and hopefully
you will accept it :-)

Regards
Patrick Siegl


Am 26.01.2011 13:41, schrieb Daniel P. Berrange:
> On Tue, Jan 25, 2011 at 08:34:03PM +0100, Patrick Siegl wrote:
>> A few more details for s390x: why you can't set param '-S' and need
>> '-chardev vc,id=cons -device virtio-serial-s390 -device
>> virtconsole,chardev=cons' on s390x:
>>
>> 1) qemu-system-s390x -M s390-virtio -vnc :0 -enable-kvm -smp 1 -m 1024
>> -k de  -kernel /boot/image-2.6.34-tue01 -initrd
>> /boot/initrd-2.6.34-tue01_GUEST -drive file=/data/sle11.img -append
>> "root=/dev/vda1 rw"
>>
>> => screenshot 1
>>
>> 2) qemu-system-s390x -S -M s390-virtio -vnc :0 -enable-kvm -smp 1 -m
>> 1024 -k de  -kernel /boot/image-2.6.34-tue01 -initrd
>> /boot/initrd-2.6.34-tue01_GUEST -drive file=/data/sle11.img -append
>> "root=/dev/vda1 rw"
>>
>> => screenshot 2
>> 3) qemu-system-s390x -M s390-virtio -vnc :0 -enable-kvm -smp 1 -m 1024
>> -k de  -kernel /boot/image-2.6.34-tue01 -initrd
>> /boot/initrd-2.6.34-tue01_GUEST -drive file=/data/sle11.img -append
>> "root=/dev/vda1 rw" -chardev vc,id=cons -device virtio-serial-s390
>> -device virtconsole,chardev=cons
>>
>>  => RUN
>>
>> 4) qemu-system-s390x -S -M s390-virtio -vnc :0 -enable-kvm -smp 1 -m
>> 1024 -k de  -kernel /boot/image-2.6.34-tue01 -initrd
>> /boot/initrd-2.6.34-tue01_GUEST -drive file=/data/sle11.img -append
>> "root=/dev/vda1 rw" -chardev vc,id=cons -device virtio-serial-s390
>> -device virtconsole,chardev=cons
>>
>> => screenshot 4
> These screenshots are all showing the same thing, but for different
> reasons.
>
> IIUC, there is no 'VGA' graphics adapter in s390 world, hence
> you need some form of text console. This is what virtio-serial-s390
> is providing for you. This does not need to be hardcoded in the
> QEMU arg generator. You can set this in the XML
>
>   <console type='vc'>
>     <target type='virtio'/>
>   </console>
>
> When you add the '-S' argument this tells QEMU to launch the binary
> but *NOT* run the guest. When libvirt uses '-S', it launches QEMU
> runs some monitor commands, and then runs 'cont' to start the
> guest running. When you're running QEMU manually in your demo
> above, I assume you never told QEMU to start the CPUs, hence you
> see the screenshot 4. If you had issued 'cont' on the monitor it
> would run normally as per example 3.
>
> Regards,
> Daniel