vif name too long when libvirt driver trying to create XEN HVM domain

[Nikita Gerasimov]

kilo-rc3

Using library: libvirt 1.2.11
Using API: Xen 1.2.11
Running hypervisor: Xen 4.5.0

network_api_class=nova.network.neutronv2.api.API

According to http://xenbits.xen.org/docs/unstable/misc/xl-network-configuration.html "If the domain is an HVM domain then the associated emulated (tap) device will have a "-emu" suffice added."
Neutron API and libvirt VIF using network_model.NIC_NAME_LEN which is 14. After XEN scripts adds "-emu" suffix vif can't be handled by xen-hotplug script:
++ ip link set vif1.0 name tap08205d6b-0a-emu
Error: argument "tap08205d6b-0a-emu" is wrong: "name" too long

[David Cheperdak (djbchepe)]

I would like to work on this, could you provide a bit more information about your setup?

Thank you,

[Nikita Gerasimov (nikita-gerasimov)]

Hi David.

What kind of information you request?
This issue is general for upstream XEN and Nova. So you can reproduce it with any Xen 4.5 and Linux as Dom0. And you need libvirt with libxl driver. Check xenproject.org for info about possible setups.

[Aleksey Zvyagintsev (azvyagintsev)]

Also, this

[Aleksey Zvyagintsev (azvyagintsev)]

* sorry, for quick-send.
 Also, this issue affects openstack-enviormetns.
Mostly, appears VM under Vmware with enables net.ifnames.

https://bugs.launchpad.net/fuel/+bug/1543378

[[e-mail] (eblock)]

Hi,

I'm currently running Openstack Mitaka on openSUSE_Leap_42.1 with
libvirt-1.3.5-587.1.x86_64
Xen version 4.7.0_08-452

and I'm still facing the same issue while trying to launch a HVM in PXE boot. Here are some logs:

###
/var/log/nova/nova-compute.log

libvirtError: internal error: libxenlight failed to create new domain 'instance-000003bd'

###
/var/log/libvirt/libxl/libxl-driver.log

2016-07-27 14:47:38 CEST libxl: error: libxl_exec.c:118:libxl_report_child_exitstatus: /etc/xen/scripts/vif-bridge add [20661] exited with error status 1
2016-07-27 14:47:38 CEST libxl: error: libxl_device.c:1222:device_hotplug_child_death_cb: script: ip link set vif140.0-emu name tap6e60bcea-c9-emu failed
2016-07-27 14:47:38 CEST libxl: error: libxl_create.c:1464:domcreate_attach_vscsictrls: unable to add nic devices

###
/var/log/xen/xen-hotplug.log

Error: argument "tapb45e5fee-6a-emu" is wrong: "name" too long

[Antony Messerli (antonym)]

I'm also seeing this issue when using an image in HVM model.

I'm using Ubuntu 16.04 with Newton and libvirt-1.3.1-1ubuntu10.1 and Xen 4.6.0-1ubuntu4.1.

There seem to have been some previous discussions here but no resolution yet:

http://www.gossamer-threads.com/lists/xen/devel/386076

I set these attributes on the image to get it into HVM mode:

hypervisor_type: xen
vm_mode: hvm

[Anthony PERARD (anthony-perard)]

Some more discussion about this on xen-devel:
https://lists.xenproject.org/archives/html/xen-devel/2016-12/msg00004.html
https://lists.xenproject.org/archives/html/xen-devel/2017-01/msg01979.html

[Sean Dague (sdague)]

Automatically discovered version kilo in description. If this is incorrect, please update the description to include 'nova version: ...'