This patch allows the new introduced __virtio_break_device() to
unbreak the virtqueue.
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/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 <[email protected]> wrote:
> This patch allows the new introduced __virtio_break_device() to
> unbreak the virtqueue.
>
> 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/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
Hm, 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);
On Wed, May 18, 2022 at 6:04 PM Cornelia Huck <[email protected]> wrote:
>
> On Wed, May 18 2022, Jason Wang <[email protected]> wrote:
>
> > This patch allows the new introduced __virtio_break_device() to
> > unbreak the virtqueue.
> >
> > 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/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
>
> Hm, to flush what?
How about "to flush the write to vq->broken"?
>
> > + * 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."?
Ok.
Thanks
>
> > + */
> > +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);
>