Re: [Qemu-devel] [PATCH 00/21] Kemari for KVM 0.2

Yoshiaki Tamura
2010-11-30T06:43:56Z

2010/11/30 Dor Laor <dlaor@redhat.com>:
> On 11/29/2010 06:23 PM, Stefan Hajnoczi wrote:
>>
>> On Mon, Nov 29, 2010 at 3:00 PM, Yoshiaki Tamura
>> <tamura.yoshiaki@lab.ntt.co.jp>  wrote:
>>>
>>> 2010/11/29 Paul Brook<paul@codesourcery.com>:
>>>>>>
>>>>>> If devices incorrectly claim support for live migration, then that
>>>>>> should
>>>>>> also be fixed, either by removing the broken code or by making it
>>>>>> work.
>>>>>
>>>>> I totally agree with you.
>>>>>
>>>>>> AFAICT your current proposal is just feeding back the results of some
>>>>>> fairly specific QA testing.  I'd rather not get into that game.  The
>>>>>> correct response in the context of upstream development is to file a
>>>>>> bug
>>>>>> and/or fix the code. We already have config files that allow third
>>>>>> party
>>>>>> packagers to remove devices they don't want to support.
>>>>>
>>>>> Sorry, I didn't get what you're trying to tell me.  My plan would
>>>>> be to initially start from a subset of devices, and gradually
>>>>> grow the number of devices that Kemari works with.  While this
>>>>> process, it'll include what you said above, file a but and/or fix
>>>>> the code.  Am I missing what you're saying?
>>>>
>>>> My point is that the whitelist shouldn't exist at all.  Devices either
>>>> support
>>>> migration or they don't.  Having some sort of separate whitelist is the
>>>> wrong
>>>> way to determine which devices support migration.
>>>
>>> Alright!
>>>
>>> Then if a user encounters a problem with Kemari, we'll fix Kemari
>>> or the devices or both. Correct?
>>
>> Is this a fair summary: any device that supports live migration workw
>> under Kemari?
>
> It might be fair summary but practically we barely have live migration
> working w/o Kemari. In addition, last I checked Kemari needs additional
> hooks and it will be too hard to keep that out of tree until all devices get
> it.

IIUC, the additional hook you're mentioning is the hack for
virtio. Michael has commented on it, I hope his patch make the
hack unnecessary.

Yoshi

>
>>
>> (If such a device does not work under Kemari then this is a bug that
>> needs to be fixed in live migration, Kemari, or the device.)
>>
>> Stefan
>
>
>