Re: [PATCH v2 1/9] crypto: virtio: Add spinlock protection with virtqueue notification

On Thu, Dec 4, 2025 at 7:22 PM Bibo Mao maobibo@loongson.cn wrote:

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

---

drivers/crypto/virtio/virtio_crypto_core.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/crypto/virtio/virtio_crypto_core.c b/drivers/crypto/virtio/virtio_crypto_core.c index 3d241446099c..ccc6b5c1b24b 100644 --- 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);
  

}

Another thing that needs to care:

There seems to be a redundant virtqueue_kick() in virtio_crypto_skcipher_crypt_req() which is out of the protection of the spinlock.

I think we can simply remote that?

Thanks

static void virtcrypto_dataq_callback(struct virtqueue *vq)

2.39.3