Re: [PATCH V5 7/9] virtio: allow to unbreak virtqueue
From: Cornelia Huck <cohuck@redhat.com>
Date: 2022-05-18 10:04:40
Also in:
linux-s390, lkml
On Wed, May 18 2022, Jason Wang [off-list ref] wrote:
quoted hunk ↗ jump to hunk
This patch allows the new introduced __virtio_break_device() to unbreak the virtqueue. Cc: Thomas Gleixner <redacted> 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);_______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization