virtio: allow to unbreak virtqueue

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>
Message-Id: <20220527060120.20964-8-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
This commit is contained in:
Jason Wang 2022-05-27 14:01:18 +08:00 committed by Michael S. Tsirkin
parent 3a232277c1
commit be83f04d25
2 changed files with 23 additions and 0 deletions

View File

@ -2395,6 +2395,28 @@ 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 the write to
* vq->broken. This should only be used in some specific case e.g
* (probing and restoring). 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);

View File

@ -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