Messages in this thread | | | From | Cornelia Huck <> | Subject | Re: [PATCH V5 7/9] virtio: allow to unbreak virtqueue | Date | Wed, 18 May 2022 12:03:56 +0200 |
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On Wed, May 18 2022, Jason Wang <jasowang@redhat.com> wrote:
> This patch allows the new introduced __virtio_break_device() to > unbreak the virtqueue. > > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: "Paul E. McKenney" <paulmck@kernel.org> > Cc: Marc Zyngier <maz@kernel.org> > Cc: Halil Pasic <pasic@linux.ibm.com> > Cc: Cornelia Huck <cohuck@redhat.com> > Cc: Vineeth Vijayan <vneethv@linux.ibm.com> > Cc: Peter Oberparleiter <oberpar@linux.ibm.com> > Cc: linux-s390@vger.kernel.org > Signed-off-by: Jason Wang <jasowang@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
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);
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