This patch allows the new introduced __virtio_break_device() to
unbreak the virtqueue.
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: "Paul E. McKenney" <paulmck at kernel.org>
Cc: Marc Zyngier <maz at kernel.org>
Cc: Halil Pasic <pasic at linux.ibm.com>
Cc: Cornelia Huck <cohuck at redhat.com>
Cc: Vineeth Vijayan <vneethv at linux.ibm.com>
Cc: Peter Oberparleiter <oberpar at linux.ibm.com>
Cc: linux-s390 at vger.kernel.org
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/virtio/virtio_ring.c | 21 +++++++++++++++++++++
include/linux/virtio.h | 1 +
2 files changed, 22 insertions(+)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index cfb028ca238e..5b7df7c455f0 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2397,6 +2397,27 @@ void virtio_break_device(struct virtio_device *dev)
}
EXPORT_SYMBOL_GPL(virtio_break_device);
+/*
+ * This should allow the device to be used by the driver. You may
+ * need to grab appropriate locks to flush. This should only be used
+ * in some specific case e.g (probing and restoring). Driver should
+ * not call this directly.
+ */
+void __virtio_unbreak_device(struct virtio_device *dev)
+{
+ struct virtqueue *_vq;
+
+ spin_lock(&dev->vqs_list_lock);
+ list_for_each_entry(_vq, &dev->vqs, list) {
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ /* Pairs with READ_ONCE() in virtqueue_is_broken(). */
+ WRITE_ONCE(vq->broken, false);
+ }
+ spin_unlock(&dev->vqs_list_lock);
+}
+EXPORT_SYMBOL_GPL(__virtio_unbreak_device);
+
dma_addr_t virtqueue_get_desc_addr(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 5464f398912a..d8fdf170637c 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -131,6 +131,7 @@ void unregister_virtio_device(struct virtio_device *dev);
bool is_virtio_device(struct device *dev);
void virtio_break_device(struct virtio_device *dev);
+void __virtio_unbreak_device(struct virtio_device *dev);
void virtio_config_changed(struct virtio_device *dev);
#ifdef CONFIG_PM_SLEEP
--
2.25.1
On Wed, May 18 2022, Jason Wang <jasowang at redhat.com> wrote:> This patch allows the new introduced __virtio_break_device() to > unbreak the virtqueue. > > Cc: Thomas Gleixner <tglx at linutronix.de> > Cc: Peter Zijlstra <peterz at infradead.org> > Cc: "Paul E. McKenney" <paulmck at kernel.org> > Cc: Marc Zyngier <maz at kernel.org> > Cc: Halil Pasic <pasic at linux.ibm.com> > Cc: Cornelia Huck <cohuck at redhat.com> > Cc: Vineeth Vijayan <vneethv at linux.ibm.com> > Cc: Peter Oberparleiter <oberpar at linux.ibm.com> > Cc: linux-s390 at vger.kernel.org > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/virtio/virtio_ring.c | 21 +++++++++++++++++++++ > include/linux/virtio.h | 1 + > 2 files changed, 22 insertions(+) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index cfb028ca238e..5b7df7c455f0 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -2397,6 +2397,27 @@ void virtio_break_device(struct virtio_device *dev) > } > EXPORT_SYMBOL_GPL(virtio_break_device); > > +/* > + * This should allow the device to be used by the driver. You may > + * need to grab appropriate locks to flush. This should only be usedHm, to flush what?> + * in some specific case e.g (probing and restoring). Driver should > + * not call this directly.Maybe "This function should only be called by the core, not directly by the driver."?> + */ > +void __virtio_unbreak_device(struct virtio_device *dev) > +{ > + struct virtqueue *_vq; > + > + spin_lock(&dev->vqs_list_lock); > + list_for_each_entry(_vq, &dev->vqs, list) { > + struct vring_virtqueue *vq = to_vvq(_vq); > + > + /* Pairs with READ_ONCE() in virtqueue_is_broken(). */ > + WRITE_ONCE(vq->broken, false); > + } > + spin_unlock(&dev->vqs_list_lock); > +} > +EXPORT_SYMBOL_GPL(__virtio_unbreak_device); > + > dma_addr_t virtqueue_get_desc_addr(struct virtqueue *_vq) > { > struct vring_virtqueue *vq = to_vvq(_vq);