Messages in this thread | | | Date | Tue, 15 Jan 2019 10:18:09 +0800 | From | Wei Wang <> | Subject | Re: [virtio-dev] [PATCH 2/2] virtio: document virtio_config_ops restrictions |
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On 01/04/2019 12:08 AM, 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@redhat.com> > --- > 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
Reviewed-by: Wei Wang <wei.w.wang@intel.com>
Best, Wei
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