On Wed, May 18 2022, Jason Wang <[email protected]> wrote: > This patch tries to implement the synchronize_cbs() for ccw. For the > vring_interrupt() that is called via virtio_airq_handler(), the > synchronization is simply done via the airq_info's lock. For the > vring_interrupt() that is called via virtio_ccw_int_handler(), a per > device rwlock is introduced ans used in the synchronization method.
s/ans/and/ > > Cc: Thomas Gleixner <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: "Paul E. McKenney" <[email protected]> > Cc: Marc Zyngier <[email protected]> > Cc: Halil Pasic <[email protected]> > Cc: Cornelia Huck <[email protected]> > Cc: Vineeth Vijayan <[email protected]> > Cc: Peter Oberparleiter <[email protected]> > Cc: [email protected] > Signed-off-by: Jason Wang <[email protected]> > --- > drivers/s390/virtio/virtio_ccw.c | 27 +++++++++++++++++++++++++++ > 1 file changed, 27 insertions(+) > > diff --git a/drivers/s390/virtio/virtio_ccw.c > b/drivers/s390/virtio/virtio_ccw.c > index d35e7a3f7067..22d36594bcdd 100644 > --- a/drivers/s390/virtio/virtio_ccw.c > +++ b/drivers/s390/virtio/virtio_ccw.c > @@ -62,6 +62,7 @@ struct virtio_ccw_device { > unsigned int revision; /* Transport revision */ > wait_queue_head_t wait_q; > spinlock_t lock; > + rwlock_t irq_lock; > struct mutex io_lock; /* Serializes I/O requests */ > struct list_head virtqueues; > bool is_thinint; > @@ -984,6 +985,27 @@ static const char *virtio_ccw_bus_name(struct > virtio_device *vdev) > return dev_name(&vcdev->cdev->dev); > } > > +static void virtio_ccw_synchronize_cbs(struct virtio_device *vdev) > +{ > + struct virtio_ccw_device *vcdev = to_vc_device(vdev); > + struct airq_info *info = vcdev->airq_info; > + > + if (info) { > + /* > + * Synchronize with the vring_interrupt() with airq indicator Maybe /* * This device uses adapter interrupts: synchronize with * vring_interrupt() called by virtio_airq_handler() via the indicator * area lock. */ > + */ > + write_lock_irq(&info->lock); > + write_unlock_irq(&info->lock); > + } else { > + /* > + * Synchronize with the vring_interrupt() called by > + * virtio_ccw_int_handler(). /* * This device uses classic interrupts: synchronize with * vring_interrupt() called by virtio_ccw_int_handler() via the * per-device irq_lock. */ > + */ > + write_lock_irq(&vcdev->irq_lock); > + write_unlock_irq(&vcdev->irq_lock); > + } > +} > + > static const struct virtio_config_ops virtio_ccw_config_ops = { > .get_features = virtio_ccw_get_features, > .finalize_features = virtio_ccw_finalize_features, > @@ -995,6 +1017,7 @@ static const struct virtio_config_ops > virtio_ccw_config_ops = { > .find_vqs = virtio_ccw_find_vqs, > .del_vqs = virtio_ccw_del_vqs, > .bus_name = virtio_ccw_bus_name, > + .synchronize_cbs = virtio_ccw_synchronize_cbs, > }; > > > @@ -1106,6 +1129,8 @@ static void virtio_ccw_int_handler(struct ccw_device > *cdev, > vcdev->err = -EIO; > } > virtio_ccw_check_activity(vcdev, activity); > + /* Local interrupt should be disabled at this time */ /* Interrupts are disabled here. */ ? Interrupts enabled here would surely be a bug. > + read_lock(&vcdev->irq_lock); > for_each_set_bit(i, indicators(vcdev), > sizeof(*indicators(vcdev)) * BITS_PER_BYTE) { > /* The bit clear must happen before the vring kick. */ _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
