On Thu, Jan 03, 2019 at 05:08:04PM +0100, Cornelia Huck wrote: > Some transports (e.g. virtio-ccw) implement virtio operations that > seem to be a simple read/write as something more involved that > cannot be done from an atomic context. > > Give at least a hint about that. > > Signed-off-by: Cornelia Huck <cohuck@xxxxxxxxxx> > --- > include/linux/virtio_config.h | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h > index 7087ef946ba7..987b6491b946 100644 > --- a/include/linux/virtio_config.h > +++ b/include/linux/virtio_config.h > @@ -12,6 +12,11 @@ struct irq_affinity; > > /** > * virtio_config_ops - operations for configuring a virtio device > + * Note: Do not assume that a transport implements all of the operations > + * getting/setting a value as a simple read/write! Generally speaking, > + * any of @get/@set, @get_status/@set_status, or @get_features/ > + * @finalize_features are NOT safe to be called from an atomic > + * context. > * @get: read the value of a configuration field > * vdev: the virtio_device > * offset: the offset of the configuration field Then might_sleep in virtio_cread/virtio_cwrite and friends would be appropriate? I guess we'll need to fix balloon first. > -- > 2.17.2 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
