[libvirt] libvirt-libxl driver defaulting to tap disk and not working (ubuntu 12.10 + xen 4.5 + libvirt 1.2.3 + openstack)

[Tian, Shuangtai]

Hi ,John ,
You are right , this problem is solved when use the default driver, 
But I found the blktap in xen4.5 was not a module, it seems a library, am I right?
And the VM also cannot start, I am not familiar whit xen, did you ever meet the below error,
Thanks for helping me so much!

328 libxl: debug: libxl_event.c:606:libxl__ev_xswatch_deregister: watch w=0x7f102c0b9518 wpath=/local/domain/0/device-model/12/state token=3/0: deregister slotnum=3
329 libxl: error: libxl_dm.c:1371:device_model_spawn_outcome: domain 12 device model: spawn failed (rc=-3)
330 libxl: error: libxl_create.c:1194:domcreate_devmodel_started: device model did not start: -3
331 libxl: error: libxl_dm.c:1475:kill_device_model: Device Model already exited
332 libxl: debug: libxl_event.c:618:libxl__ev_xswatch_deregister: watch w=0x7f102c0cb640: deregister unregistered
333 libxl: debug: libxl_event.c:618:libxl__ev_xswatch_deregister: watch w=0x7f102c0cb850: deregister unregistered
334 libxl: debug: libxl_event.c:618:libxl__ev_xswatch_deregister: watch w=0x7f102c0cb220: deregister unregistered
335 libxl: debug: libxl_event.c:1739:libxl__ao_complete: ao 0x7f102c0c8820: complete, rc=-3
336 libxl: debug: libxl_event.c:1711:libxl__ao__destroy: ao 0x7f102c0c8820: destroy


-----Original Message-----
From: John Haxby [mailto:john.haxby at oracle.com] 
Sent: Thursday, April 17, 2014 10:31 PM
To: Tian, Shuangtai; libvir-list at redhat.com
Subject: Re: [libvirt] libvirt-libxl driver defaulting to tap disk and not working (ubuntu 12.10 + xen 4.5 + libvirt 1.2.3 + openstack)

On 17/04/14 10:51, Tian, Shuangtai wrote:
>       <driver name="tap2" type="raw" cache="none"/>
> 

As I recall, tap2 is deprecated and libxl will fail with it.   Perhaps
try tap or just leaving the driver as default?

jch