libvirt users - Jan 2012 - Hotplug/hotadd functionality of libvirt?

Hello,

First of all, happy new year!

I am interested in the hot plugging facilities of libvirt, in particular 
in what qemu calls 'hot add' of network interface cards. (And also the 
reverse: hot unplugging/removing of NICs.)

I think I am overlooking something, but so far the best I have been able 
to find is:

http://libvirt.org/sources/virshcmdref/html/

and it is not entirely clear to me what the relevant virsh commands are. 
The most obvious choice seems to be the iface-* commands such as

http://libvirt.org/sources/virshcmdref/html/sect-iface-define.html

but these seem to be about physical rather than virtual network 
interfaces, and the documentation `needs to be written' anyway, and from 
the copyright notice the manual seems to be somewhat outdated by now.

Can you give me a little help with this? Is such hot plug/add 
functionality supported by libvirt in the first place? Is there some 
kind of overview document about this? What is the most authoritative 
documentation of this functionality? Is there a Java or C API to access 
this functionality?

Thank you for any help you can give me,

-- 
Kees van Reeuwijk

On 03.01.2012 14:39, Kees van Reeuwijk wrote:
> Hello,
> 
> First of all, happy new year!
> 
> I am interested in the hot plugging facilities of libvirt, in particular
> in what qemu calls 'hot add' of network interface cards. (And also
the
> reverse: hot unplugging/removing of NICs.)
> 
> I think I am overlooking something, but so far the best I have been able
> to find is:
> 
> http://libvirt.org/sources/virshcmdref/html/
> 
> and it is not entirely clear to me what the relevant virsh commands are.
> The most obvious choice seems to be the iface-* commands such as
> 
> http://libvirt.org/sources/virshcmdref/html/sect-iface-define.html
> 
> but these seem to be about physical rather than virtual network
> interfaces, and the documentation `needs to be written' anyway, and
from
> the copyright notice the manual seems to be somewhat outdated by now.
> 
> Can you give me a little help with this? Is such hot plug/add
> functionality supported by libvirt in the first place? Is there some
> kind of overview document about this? What is the most authoritative
> documentation of this functionality? Is there a Java or C API to access
> this functionality?
> 
> Thank you for any help you can give me,
> 
I think virsh attach-interface / detach-interface is what you are
looking for. Another option is to write a little XML snippet and virsh
attach-device it.

Michal