Hi

thanks for your reply

Since I am working on my master thesis and seriously I am running out of time I decided to downgrade my libvirt from 1.1.1 to 1.0.2 to be able to continue working on my thesis. Now it works !

But for your information , I already checked the XML file and the interface was really removed. I checked my host interfaces using ifconfig -a and I found however I released the device but it is not there and it is not possible to assign it to other VM so I though it means there is some missed procedure or some thing like this to unbind pci device ! as i mentioned if I restarted the libvirt service I was able to attach it again but still it was not shown in ifconfig -a list. The other point that i noticed was the number of "irq"s in my logs for MSI/MSI-X while attaching device. I am not a programmer and I have no clue about interrupts but the point was that in 1.1.1 i cloud see only 2 or 3 "irq" in my logs but now I see 7 or 8 . 

regards
Mohsen



On Fri, Mar 28, 2014 at 10:34 AM, Michal Privoznik <mprivozn@redhat.com> wrote:
On 27.03.2014 13:53, Mohsen Ghaemi wrote:
Hi all

I just encountered a problem in libvirt while was trying to attach and
detach a sr-iov vf to my VM


The version of my libvirt is 1.1.1-0ubuntu8.5


I tried to attach the device using following xml


<interface type='hostdev' managed='yes'>

    <mac address='5c:01:fd:12:34:58'/>

    <source>

        <address type='pci' domain='0x0000' bus='0x04' slot='0x01'
function='0x1'/>

    </source>

</interface>


When i attached device it worked properly and i managed to ping another
host.


virsh # attach-device t5 1.xml

Device attached successfully


But when i detached it still i had network traffic in my VM but libvirt
(virsh) said that


virsh # detach-device t5 1.xml

Device detached successfully


The next time i tried to attach it libvirt said that


virsh # attach-device t5 1.xml

error: Failed to attach device from 1.xml

error: Requested operation is not valid: PCI device 0000:04:01.1 is in
use by domain t5


and when i continue this action after the ‘domain’ i receive some
strange characters which might come from the memory space (memory
content) like some addresses, links or some characters


I tried it with different VMs and different guest OSs that the same happend.


The same action was done with another host running libvirt version


Installed: 1.0.2-0ubuntu11.13.04.5~cloud1

Candidate: 1.0.2-0ubuntu11.13.04.5~cloud1

This is probably a bug in libvirt. There's been a rework of hostdev plugging and unplugging recently. Can you try the 1.2.3-rc1 and see if the problem is gone?

Michal