Error: Device 0 (vif) could not be connected. (Xen 3.0.1 regression)

[Philippe Berthault <Philippe.Berthault@Bull.net>]

I've compiled and installed the latest Xen release (3.0.1) on my PC.

The previous Xen release, I've used, built on unstable Xen sources on
december 2005, worked very well and with this previous unstable release,
I was able to boot a Linux Knoppix in a Xen domain without any problem.

But with the latest Xen release 3.0.1, the Knoppix boot in a user domain
fails with the following message :
Error: Device 0 (vif) could not be connected. Backend device not found.

My understanding is that the problem comes from Domain-0.
Thanks for your help.

Here an extract of the xend.log file:

2006-02-07 16:38:45 xend] DEBUG (DevController:133) Waiting for devices vif.
[2006-02-07 16:38:45 xend] DEBUG (DevController:139) Waiting for 0.
[2006-02-07 16:38:45 xend] DEBUG (DevController:409) 
hotplugStatusCallback /local/domain/0/backend/vif/4/0/hotplug-status.
[2006-02-07 16:38:45 xend] DEBUG (DevController:409) 
hotplugStatusCallback /local/domain/0/backend/vif/4/0/hotplug-status.
[2006-02-07 16:38:45 xend] DEBUG (DevController:426) 
hotplugStatusCallback 3.
[2006-02-07 16:38:45 xend] ERROR (SrvBase:87) Request wait_for_devices 
failed.
Traceback (most recent call last):
  File "/usr/lib/python/xen/web/SrvBase.py", line 85, in perform
    return op_method(op, req)
  File "/usr/lib/python/xen/xend/server/SrvDomain.py", line 72, in 
op_wait_for_devices
    return self.dom.waitForDevices()
  File "/usr/lib/python/xen/xend/XendDomainInfo.py", line 1349, in 
waitForDevices
    self.waitForDevices_(c)
  File "/usr/lib/python/xen/xend/XendDomainInfo.py", line 977, in 
waitForDevices_
    return self.getDeviceController(deviceClass).waitForDevices()
  File "/usr/lib/python/xen/xend/server/DevController.py", line 135, in 
waitForDevices
    return map(self.waitForDevice, self.deviceIDs())
  File "/usr/lib/python/xen/xend/server/DevController.py", line 151, in 
waitForDevice
    raise VmError("Device %s (%s) could not be connected. "
VmError: Device 0 (vif) could not be connected. Backend device not found.