Messages in this thread | | | Date | Mon, 6 Oct 2014 16:08:16 +0200 | From | Cornelia Huck <> | Subject | Re: [PATCH 10/16] virtio: add API to enable VQs early |
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On Sun, 5 Oct 2014 19:07:19 +0300 "Michael S. Tsirkin" <mst@redhat.com> wrote:
> virtio spec requires DRIVER_OK to be set before > VQs are used, but some drivers use VQs before probe > function returns. > Since DRIVER_OK is set after probe, this violates the spec.
"Even though transitional devices support this behaviour, we want to make it possible for those early callers to become spec compliant."
?
> > Add API for drivers to call before using VQs. > > Sets DRIVER_OK internally. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > include/linux/virtio_config.h | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h > index e8f8f71..6127fc8 100644 > --- a/include/linux/virtio_config.h > +++ b/include/linux/virtio_config.h > @@ -109,6 +109,23 @@ struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev, > return vq; > } > > +/** > + * virtio_early_enable_vqs - enable vq use in probe function > + * @vdev: the device > + * > + * Driver must call this to use vqs in the probe function. > + * > + * Note: vqs are enabled automatically after probe returns. > + */ > +static inline > +void virtio_early_enable_vqs(struct virtio_device *dev) > +{ > + unsigned status = dev->config->get_status(dev); > + > + BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK); > + dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK); > +} > +
Maybe virtio_enable_vqs_early() instead?
> static inline > const char *virtio_bus_name(struct virtio_device *vdev) > {
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