On Thu, 3 Jan 2019 11:28:28 -0500 "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > 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. Yes, it makes sense to go over the code and add might_sleep to functions where it makes sense after the balloon changes have been merged. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
