[libvirt-users] <qemu:commandline> domain XML tag is not working?

[Thomas Stein]

Am 21.04.15 um 03:44 schrieb Chengyuan Li:
> Hi Eric,
> 
> Thanks!
> You are right, I missed declaring namespace, now, the <qemu:commandline> is
> saved after virsh edit.

Nice. Can you give a full example? Also are the limitations still the
same as of 2013? This is what the internet is telling me.

- Image formats are not supported (qcow2, qed, etc).
- Live migration is not supported.
- QEMU I/O throttling is not supported but cgroups blk-io controller can
be used.
- Only the default "report" I/O error policy is supported (-drive
werror=,rerror=).
- Hot unplug is not supported.
- Block jobs (block-stream, drive-mirror, block-commit) are not supported.

cheers
t.

> Regards,
> CY.
> 
> On Mon, Apr 20, 2015 at 11:41 PM, Eric Blake <eblake at redhat.com> wrote:
> 
>> On 04/20/2015 08:37 AM, Chengyuan Li wrote:
>> > Hi,
>> >
>> > I tried to enable virtio-blk data plane feature for VMs in my openstack
>> > environment,  the hypervisor is ubuntu 14.04, libvirt 1.2.2 and QEMU 2.0.
>> > As nova doesn't support that parameter yet, I did belows
>> >
>> > 1. nova boot a VM with raw disk image.
>> > 2. nova stop the VM.
>> > 3. run "virsh edit <instance-id>" on the hyprvisor node, and adding below
>> > into instance xml just before </domain>.
>> >
>> > However, the <qemu:commandline> part is ignored and not saved after
>> closing
>> > virsh edit, seems that libvirt rejected these changes. Is there any XML
>> > syntax error here? Or libvirt doesn't support <qemu:commandline> tag?
>>
>> If XML changes disappear after virsh edit, then it is a case of you
>> using XML that wasn't recognized by libvirt.
>>
>> >
>> > <qemu:commandline>
>> >     <qemu:arg value='-set'/>
>> >     <qemu:arg value='device.drive-virtio-disk0.x-data-plane=on'/>
>> > </qemu:commandline>
>>
>> Did you also remember to declare the namespace? Per
>> http://libvirt.org/drvqemu.html#qemucommand
>>
>> it is essential to have something like:
>>
>> <domain type='qemu' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0
>> '>
>>
>> before any other <qemu:...> will be recognized.  (The namespace does not
>> have to be named 'qemu:', but it makes it easier to stick to the naming
>> used by the examples)
>>
>> --
>> Eric Blake   eblake redhat com    +1-919-301-3266
>> Libvirt virtualization library http://libvirt.org
>>
>>
> 
> 
> 
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