Commit 47e5b32b authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by Pengyuan Zhao
Browse files

virtio: document virtio_reset_device 

mainline inclusion
from mainline-v5.17-rc8
commit c46eccda
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5WXCZ
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c46eccdaadabb7822080a04e633f81b2ad37f358



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Looks like most callers get driver/device removal wrong.
Document what's expected of callers.

Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarPengyuan Zhao <zhaopengyuan@hisilicon.com>
parent 84b7fc44

drivers/virtio/virtio.c

+16 −0
Original line number Diff line number Diff line
@@ -203,6 +203,22 @@ static int virtio_features_ok(struct virtio_device *dev) 
	return 0;

}



/**

 * virtio_reset_device - quiesce device for removal

 * @dev: the device to reset

 *

 * Prevents device from sending interrupts and accessing memory.

 *

 * Generally used for cleanup during driver / device removal.

 *

 * Once this has been invoked, caller must ensure that

 * virtqueue_notify / virtqueue_kick are not in progress.

 *

 * Note: this guarantees that vq callbacks are not in progress, however caller

 * is responsible for preventing access from other contexts, such as a system

 * call/workqueue/bh.  Invoking virtio_break_device then flushing any such

 * contexts is one way to handle that.

 * */

void virtio_reset_device(struct virtio_device *dev)

{

	dev->config->reset(dev);