[RFC v2 0/3] fio-ccw fixes for kernel stacktraces

Farhan Ali
2019-04-08T21:05:30Z

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

ChangeLog
---------
v1 -> v2
- Use the return code from cio_cancel_halt_clear to prevent
waiting unnecessarily (patch 2).

- No need to reset the device on the remove path (patch 3).

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 | 27 ++++++++++++---------------
drivers/s390/cio/vfio_ccw_ops.c | 11 ++++++++++-
2 files changed, 22 insertions(+), 16 deletions(-)

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2.7.4