On Tue, Jan 20, 2009 at 04:44:22PM +0100, Daniel Schwager wrote:
Hi Daniel,
thx for the fast answer.
QEMU is responsible for passing arguments to the interface scripts, so its out of libvirt's control. QEMU passes a single paramter to the script, which is the name of the TAP device interface being added. If you don't give a <target dev='tap3'> libvirt generates a TAP device name vnetXXXX.
If I do not specify the <target>-element inside of <interface>, your docu told me
"The guest will have a tun device created with a name of vnetN, which can also be overridden with the <target> element." (http://www.libvirt.org/formatdomain.html#elementsNICS)
I understood this in the following way: I can remove the target-element and I will get automatically a target name "vnet<N>" - if I do this, I will get an interfacename "(null") :
5459 ? Sl 0:01 /usr/bin/kvm -S -M pc -m 500 -smp 1 -name solidcam -uuid 60a8db24-86a5-f9fc-16ee-b60b32411dd8 -monitor pty -boot c -drive file=/srv/winxp127-xxx.dsk,if=ide,index=0,boot=on -net nic,macaddr=52:54:00:46:58:41,vlan=0 -net tap,ifname=(null),script=/etc/kvm/qemu-ifup,vlan=0 -serial pty -parallel none -usb -usbdevice tablet -vnc 0.0.0.0:0
That is a bug I'm afraid - it *should* pass the real auto-generated interface name but for some reason it isn't. I see this is one of the XML configs we don't have tested in our xml -> ARGV conversion test.
So, this means libvirt is NOT responsible for the naming auf the target. Maybe you have to clarify this in the docu.
For my case, I have to write a domain-xml dynamically and specify the interface name (target-element) to the domain-xml like
<interface type='ethernet'> <script path='/etc/kvm/qemu-ifup'/> <target dev='my-new-name001122'/> </interface>
Yes, explicitly giving a interface name is a reasonable workaround until i fix the bug. Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|