crypto: virtio - handle config changed by work queue

MST pointed out: config change callback is also handled incorrectly
in this driver, it takes a mutex from interrupt context.

Handle config changed by work queue instead.

Cc: Gonglei (Arei) <arei.gonglei@huawei.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/virtio/virtio_crypto_common.h

@@ -35,6 +35,9 @@ struct virtio_crypto {
 	struct virtqueue *ctrl_vq;
 	struct data_queue *data_vq;
 
+	/* Work struct for config space updates */
+	struct work_struct config_work;
+
 	/* To protect the vq operations for the controlq */
 	spinlock_t ctrl_lock;
 

drivers/crypto/virtio/virtio_crypto_core.c

@@ -335,6 +335,14 @@ static void virtcrypto_del_vqs(struct virtio_crypto *vcrypto)
 	virtcrypto_free_queues(vcrypto);
 }
 
+static void vcrypto_config_changed_work(struct work_struct *work)
+{
+	struct virtio_crypto *vcrypto =
+		container_of(work, struct virtio_crypto, config_work);
+
+	virtcrypto_update_status(vcrypto);
+}
+
 static int virtcrypto_probe(struct virtio_device *vdev)
 {
 	int err = -EFAULT;
@@ -454,6 +462,8 @@ static int virtcrypto_probe(struct virtio_device *vdev)
 	if (err)
 		goto free_engines;
 
+	INIT_WORK(&vcrypto->config_work, vcrypto_config_changed_work);
+
 	return 0;
 
 free_engines:
@@ -490,6 +500,7 @@ static void virtcrypto_remove(struct virtio_device *vdev)
 
 	dev_info(&vdev->dev, "Start virtcrypto_remove.\n");
 
+	flush_work(&vcrypto->config_work);
 	if (virtcrypto_dev_started(vcrypto))
 		virtcrypto_dev_stop(vcrypto);
 	virtio_reset_device(vdev);
@@ -504,7 +515,7 @@ static void virtcrypto_config_changed(struct virtio_device *vdev)
 {
 	struct virtio_crypto *vcrypto = vdev->priv;
 
-	virtcrypto_update_status(vcrypto);
+	schedule_work(&vcrypto->config_work);
 }
 
 #ifdef CONFIG_PM_SLEEP
@@ -512,6 +523,7 @@ static int virtcrypto_freeze(struct virtio_device *vdev)
 {
 	struct virtio_crypto *vcrypto = vdev->priv;
 
+	flush_work(&vcrypto->config_work);
 	virtio_reset_device(vdev);
 	virtcrypto_free_unused_reqs(vcrypto);
 	if (virtcrypto_dev_started(vcrypto))