Re: [PATCH 0/2] s390/vfio-ap: do not open code locks for VFIO_GROUP_NOTIFY_SET_KVM notification

[Cornelia Huck <cohuck@redhat.com>]

On Wed, Aug 18 2021, Alex Williamson <alex.williamson@redhat.com> wrote:

> On Wed, 18 Aug 2021 17:59:51 +0200
> Christian Borntraeger <borntraeger@de.ibm.com> wrote:
>
>> On 02.08.21 18:32, Tony Krowiak wrote:
>> > 
>> > 
>> > On 8/2/21 9:53 AM, Halil Pasic wrote:  
>> >> On Mon, 2 Aug 2021 09:10:26 -0400
>> >> Tony Krowiak <akrowiak@linux.ibm.com> wrote:
>> >>  
>> >>> PING!
>> >>>
>> >>> This patch will pre-req version 17 of a patch series I have waiting in
>> >>> the wings,
>> >>> so I'd like to get this one merged ASAP. In particular, if a KVM
>> >>> maintainer can
>> >>> take a look at the comments concerning the taking of the kvm->lock
>> >>> before the
>> >>> matrix_mdev->lock it would be greatly appreciated. Those comments begin with
>> >>> Message ID <20210727004329.3bcc7d4f.pasic@linux.ibm.com> from Halil Pasic.  
>> >> As far as I'm concerned, we can move forward with this. Was this
>> >> supposed to go in via Alex's tree?  
>> > 
>> > I am not certain, Christian queued the previous patches related to
>> > this on:
>> > 
>> > 
>> > https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/log/?h=fixes
>> > 
>> > Jason G., since this will need to be integrated with your other patches,
>> > where should this be queued?  
>> 
>> 
>> This previous patch (s390/vfio-ap: clean up mdev resources when remove callback invoked) is
>> already in master.
>> Can you respin the series with all Acks and RBs?
>> 
>> Alex, can you then take these 2 patches via your tree? Thanks
>> 
>> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> for this series.
>
>
> I see some review feedback that seems to suggest a new version would be
> posted:
>
> https://lore.kernel.org/linux-s390/0f03ab0b-2dfd-e1c1-fe43-be2a59030a71@linux.ibm.com/

Yeah, I thought so as well. But it also looks like something that could
be a fixup on top.

>
> I also see in this thread:
>
> https://lore.kernel.org/linux-s390/20210721164550.5402fe1c.pasic@linux.ibm.com/
>
> that Halil's concern's around open/close races are addressed by Jason's
> device_open/close series that's already in my next branch and he
> provided an Ack, but there's still the above question regarding the
> kvm->lock that was looking for a review from... I'm not sure, maybe
> Connie or Paolo.  Christian, is this specifically what you're ack'ing?

I'm also unsure about the kvm->lock thing. Is taking the lock buried
somewhere deep in the code that will ultimately trigger the release?
I would at least like a pointer.

>
> It can ultimately go in through my tree, but not being familiar with
> this code I'd hope for more closure.  Thanks,
>
> Alex