On Sun, 5 Oct 2014 19:07:05 +0300 "Michael S. Tsirkin" <[email protected]> wrote:
> Defer config changed notifications that arrive during > probe/scan/freeze/restore. > > This will allow drivers to set DRIVER_OK earlier, without worrying about > racing with config change interrupts. > > This change will also benefit old hypervisors (before 2009) > that send interrupts without checking DRIVER_OK: previously, > the callback could race with driver-specific initialization. > > This will also help simplify drivers. > > Signed-off-by: Michael S. Tsirkin <[email protected]> > --- > include/linux/virtio.h | 6 ++++++ > drivers/virtio/virtio.c | 55 > +++++++++++++++++++++++++++++++++++++++++-------- > 2 files changed, 52 insertions(+), 9 deletions(-) > > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c > index 657f817..578e02d 100644 > --- a/drivers/virtio/virtio.c > +++ b/drivers/virtio/virtio.c > @@ -117,6 +117,40 @@ void virtio_check_driver_offered_feature(const struct > virtio_device *vdev, > } > EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature); > > +static void __virtio_config_changed(struct virtio_device *dev) > +{ > + struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); > + > + if (!dev->config_enabled) > + dev->config_changed = true; > + else if (drv && drv->config_changed) > + drv->config_changed(dev); > +} > + > +void virtio_config_changed(struct virtio_device *dev) > +{ > + spin_lock_irq(&dev->config_lock); > + __virtio_config_changed(dev); > + spin_unlock_irq(&dev->config_lock); Hm, isn't this function called from the interrupt handler? > +} > +EXPORT_SYMBOL_GPL(virtio_config_changed); > + > +static void virtio_config_disable(struct virtio_device *dev) > +{ > + spin_lock_irq(&dev->config_lock); > + dev->config_enabled = false; > + spin_unlock_irq(&dev->config_lock); > +} > + > +static void virtio_config_enable(struct virtio_device *dev) > +{ > + spin_lock_irq(&dev->config_lock); > + dev->config_enabled = true; > + __virtio_config_changed(dev); > + dev->config_changed = false; > + spin_unlock_irq(&dev->config_lock); > +} > + Maybe call these virtio_config_change_{dis,en}able()? > static int virtio_dev_probe(struct device *_d) > { > int err, i; _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
