[Kimchi-devel] RFC - PCI Hot Plug

[Jose Ricardo Ziviani]

On 30-03-2015 16:44, Jose Ricardo Ziviani wrote:
>
>
> On 30-03-2015 11:01, Daniel Henrique Barboza wrote:
>>
>> On 03/27/2015 03:22 PM, Jose Ricardo Ziviani wrote:
>>> Hello everybody!
>>>
>>> I tried PCI Hot Plug in Kimchi but it didn't work as expected. Once my
>>> VM was running I plugged my audio device into my VM successfully, I
>>> was able to use it flawlessly.
>>>
>>> However, if I reboot (or completely turn off/on), the VM will not boot
>>> anymore. It tries to exclusively get the device but for some reason
>>> (libvirt bug?) that device was not detached from the host. Then, I
>>> must to turn off the VM amd remove the PCI using Kimchi to be able to
>>> boot it again.
>>
>> Unfortunately the only way to tell if it's Kimchi or libvirt's fault is
>> to try to do the
>> whole process without Kimchi. In other words, creating the VM and
>> plug/unplug
>> the PCI devices using virsh.
>>
>>>
>>> Such behavior doesn't happen if I add the PCI when the VM is turned
>>> off. Also, virt-manager doesn't look to support hot plug, it throws a
>>> libvirt exception (libvirtmod.virDomainAttachDevice) if I try to add a
>>> PCI while VM is running.
>>
>>
>> virt-manager can be a good benchmark of libvirt current capabilities ( I
>> believe both are
>> maintained by Red Hat). If latest virt-manager does not support PCI hot
>> plug there is a good
>> chance that libvirt support for this feature is not complete or it is in
>> early stages.
>>
>> This only makes libvirt only testing more critical. We need to determine
>> exactly where
>> libvirt is as far as PCI Hot Plug is concerned.
>>
>>>
>>> Does anybody have experienced it before, any advise?
>>>
>>> Thank you
>>>
>>>
>>
>> _______________________________________________
>> Kimchi-devel mailing list
>> Kimchi-devel at ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/kimchi-devel
>>
>
> Daniel,
>
> Thank you for all the information. I tested here again and it worked fine.
>
> In my VM I was running Debian with an older kernel. Now, with Ubuntu
> 10.10 it worked flawlessly. That problem reported seems to be the guest
> running an older kernel, nothing to do with libvirt or kimchi.

*Ubuntu 14.10

>
> I'll continue my testing using different combinations. I'll report here
> as soon as possible (unfortunately my network is not good today).
>
> Regards!
>

-- 
Jose Ricardo Ziviani
-----------------------------
Software Engineer
Linux Technology Center - IBM