crypto: virtio - Add spinlock protection with virtqueue notification

When VM boots with one virtio-crypto PCI device and builtin backend,
run openssl benchmark command with multiple processes, such as
  openssl speed -evp aes-128-cbc -engine afalg  -seconds 10 -multi 32

openssl processes will hangup and there is error reported like this:
 virtio_crypto virtio0: dataq.0:id 3 is not a head!

It seems that the data virtqueue need protection when it is handled
for virtio done notification. If the spinlock protection is added
in virtcrypto_done_task(), openssl benchmark with multiple processes
works well.

Fixes: fed93fb62e05 ("crypto: virtio - Handle dataq logic with tasklet")
Cc: stable@vger.kernel.org
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/virtio/virtio_crypto_core.c b/drivers/crypto/virtio/virtio_crypto_core.c
index 3d241446099cc9d52c6c43fd513c19b10d513581..ccc6b5c1b24b37e0adf8532d2a44746fbd98b10b 100644 (file)
--- a/drivers/crypto/virtio/virtio_crypto_core.c
+++ b/drivers/crypto/virtio/virtio_crypto_core.c
@@ -75,15 +75,20 @@ static void virtcrypto_done_task(unsigned long data)
        struct data_queue *data_vq = (struct data_queue *)data;
        struct virtqueue *vq = data_vq->vq;
        struct virtio_crypto_request *vc_req;
+       unsigned long flags;
        unsigned int len;
 
+       spin_lock_irqsave(&data_vq->lock, flags);
        do {
                virtqueue_disable_cb(vq);
                while ((vc_req = virtqueue_get_buf(vq, &len)) != NULL) {
+                       spin_unlock_irqrestore(&data_vq->lock, flags);
                        if (vc_req->alg_cb)
                                vc_req->alg_cb(vc_req, len);
+                       spin_lock_irqsave(&data_vq->lock, flags);
                }
        } while (!virtqueue_enable_cb(vq));
+       spin_unlock_irqrestore(&data_vq->lock, flags);
 }
 
 static void virtcrypto_dataq_callback(struct virtqueue *vq)