Re: [PATCH] kvm: remove in_range from kvm_io_device

Gregory Haskins
2009-06-25T13:19:48Z

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Michael S. Tsirkin wrote:
> On Thu, Jun 25, 2009 at 09:02:28AM -0400, Gregory Haskins wrote:
>
>>> Here's what I have in mind:
>>> kvm does
>>> lock
>>> dev = find
>>> unlock
>>>
>>> <---------- at this point group device is removed
>>>
>>> write access to device that has been removed
>>>
>>>
>>>
>>>
>> Hmm...you are right. This looks like it was introduced with that recent
>> locking patch you cited. Well, I can still fix it now easily by putting
>> an rcu-read-lock around the access. Longer term we should move to
>> srcu. Thoughts?
>>
>> -Greg
>>
>>
>
>
> Some callbacks take kvm mutex lock. So it seems rcu won't work,
> we need srcu.
>
>

Indeed. I will put something together.

We should consider merging the io_bus cleanup I have for deregister
support ASAP as well.