At a minimum, I don't see why it's part of the series. Host can always
crash the guest if it wants to ...
The point of BUG_ON is device or driver is already corrupted so we
should not try to drive it. If you still want this in pls come up with
a better commit log explaining the why.
On Fri, May 27, 2022 at 02:01:20PM +0800, Jason Wang wrote:
> We used to use BUG_ON() in virtio_device_ready() to detect illegal
not really, BUG_ON just crashes the kernel. we detect by checking
status.
> status value, this seems sub-optimal since the value is under the
> control of the device. Switch to use WARN_ON() instead.
some people use crash on warn so ...
>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
> Cc: Marc Zyngier <maz@xxxxxxxxxx>
> Cc: Halil Pasic <pasic@xxxxxxxxxxxxx>
> Cc: Cornelia Huck <cohuck@xxxxxxxxxx>
> Cc: Vineeth Vijayan <vneethv@xxxxxxxxxxxxx>
> Cc: Peter Oberparleiter <oberpar@xxxxxxxxxxxxx>
> Cc: linux-s390@xxxxxxxxxxxxxxx
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> ---
> include/linux/virtio_config.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
> index d4edfd7d91bb..9a36051ceb76 100644
> --- a/include/linux/virtio_config.h
> +++ b/include/linux/virtio_config.h
> @@ -255,7 +255,7 @@ void virtio_device_ready(struct virtio_device *dev)
> {
> unsigned status = dev->config->get_status(dev);
>
> - BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);
> + WARN_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);
>
we lose debuggability as guest will try to continue.
if we are doing this let us print a helpful message and dump a lot of
state right here.
> /*
> * The virtio_synchronize_cbs() makes sure vring_interrupt()
> --
> 2.25.1
