vfio-ccw fixes for kernel stacktraces

Hi,

I have recently seen some interesting kernel stacktraces while testing vfio-ccw mediated devices. These stack traces are seen when things don't go right, for example when a guest crashes or dies while still doing some I/O on the mediated device.

I have also come across an issue in the common vfio code as
well which I reported upstream (https://marc.info/?l=kvm&m=155369393523503&w=2)
and submitted a patch separately for it
(https://marc.info/?l=kvm&m=155414703613868&w=2).

I would appreciate any review or feedback on these patches.

Thanks
Farhan

Farhan Ali (3):
vfio-ccw: Do not call flush_workqueue while holding the spinlock
vfio-ccw: Prevent quiesce function going into an infinite loop
vfio-ccw: Release any channel program when releasing/removing vfio-ccw
mdev

 drivers/s390/cio/vfio_ccw_drv.c | 28 ++++++++++++----------------
 drivers/s390/cio/vfio_ccw_ops.c |  9 +++++++++
 2 files changed, 21 insertions(+), 16 deletions(-)

2.7.4