Commit be83f04d authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

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: default avatarJason Wang <jasowang@redhat.com>
Message-Id: <20220527060120.20964-8-jasowang@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarXuan Zhuo <xuanzhuo@linux.alibaba.com>
parent 3a232277

drivers/virtio/virtio_ring.c

+22 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/virtio.h

+1 −0
Original line number Diff line number Diff line
@@ -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