From 4f76617378ee97c557b526cb58d3c61eb0a9c963 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Tue, 8 Jan 2019 15:53:03 +0100 Subject: vfio-ccw: protect the I/O region Introduce a mutex to disallow concurrent reads or writes to the I/O region. This makes sure that the data the kernel or user space see is always consistent. The same mutex will be used to protect the async region as well. Reviewed-by: Eric Farman Signed-off-by: Cornelia Huck --- drivers/s390/cio/vfio_ccw_private.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/s390/cio/vfio_ccw_private.h') diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index 50c52efb4fcb..32173cbd838d 100644 --- 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 regions * @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; -- cgit v1.2.3