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

Cornelia Huck
2019-04-15T16:45:24Z

On Mon, 8 Apr 2019 17:05:30 -0400
Farhan Ali <alifm@linux.ibm.com> wrote:

> 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(-)
>

Thanks, queued patches 1 and 3.