Re: [PATCH 2/2] s390/vfio-ap: replace open coded locks for VFIO_GROUP_NOTIFY_SET_KVM notification

[Halil Pasic]

On Wed, 28 Jul 2021 09:43:03 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:

> This solution was suggested by Jason G and it does in fact resolve
> the lockdep splat encountered when starting an SE guest with
> access to crypto resources. There is a chance that the KVM lock
> can get held while waiting for the lock on the matrix_dev->mutex,
> but this does not seem like a grave concern to me. 

Yes I agree. I was thinking along the lines: matrix modifications
via the sysfs take the matrix_dev->lock so the level of contention
may depend on what userspace is doing...

Regards,
Halil