[Intel-gfx] [PATCH v3] vfio: fix deadlock between group lock and kvm lock

[Matthew Rosato]

On 2/3/23 3:58 AM, Liu, Yi L wrote:
> Hi Matthew,
> 
...
>> * Can't pass group->kvm to vfio_device_open, as it references the value
>>   outside of new lock.  Pass device->kvm to minimize changes in this
>>   fix (Alex, Yi)
...
>> @@ -361,7 +420,6 @@ static int vfio_device_first_open(struct vfio_device
>> *device,
>>  	if (ret)
>>  		goto err_module_put;
>>
>> -	device->kvm = kvm;
> 
> Since you've deleted the only usage of kvm pointer in this function, I
> guess you can remove the kvm parameter from vfio_device_open()
> and vfio_device_first_open(). :-) if it makes this patch too big, may
> just have another patch to do it.
> 

Hi Yi,

Yeah, I mentioned it briefly (and vaguely I guess) in the cover, that was intentionally left out to reduce the patch size since this is a fix.  I thought that was the consensus from the v2 comments anyway.

If I end up doing a v4 for this I can just include the removal as a 2nd patch (without a fixes tag) and Alex can squash or keep separate as preferred -- if not you can feel free to do that removal with your cdev follow-up that exploits this work.   

Thanks,
Matt