On Mon, 21 Jan 2019 12:03:51 +0100
Cornelia Huck <cohuck@xxxxxxxxxx> wrote:
> --- a/drivers/s390/cio/vfio_ccw_private.h
> +++ b/drivers/s390/cio/vfio_ccw_private.h
> @@ -28,6 +28,7 @@
> * @mdev: pointer to the mediated device
> * @nb: notifier for vfio events
> * @io_region: MMIO region to input/output I/O arguments/results
> + * @io_mutex: protect against concurrent update of I/O structures
We could be a bit more specific about what does this mutex guard.
Is it only io_region, or cp, irb and the new regions a well? ->state does
not seem to be covered, but should need some sort of synchronisation
too, or?
> * @cp: channel program for the current I/O operation
> * @irb: irb info received from interrupt
> * @scsw: scsw info
> @@ -42,6 +43,7 @@ struct vfio_ccw_private {
> struct mdev_device *mdev;
> struct notifier_block nb;
> struct ccw_io_region *io_region;
> + struct mutex io_mutex;
>
> struct channel_program cp;
> struct irb irb;
> --
