RE: [RFC v1 2/2] crypto/virtio-crypto: Register an algo only if it's supported

[Gonglei (Arei)]

> -----Original Message-----
> From: Farhan Ali [mailto:alifm@xxxxxxxxxxxxx]
> Sent: Saturday, June 09, 2018 3:09 AM
> To: linux-kernel@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx
> Cc: mst@xxxxxxxxxx; qemu-devel@xxxxxxxxxx; Gonglei (Arei)
> <arei.gonglei@xxxxxxxxxx>; longpeng <longpeng2@xxxxxxxxxx>;
> pasic@xxxxxxxxxxxxx; frankja@xxxxxxxxxxxxx; borntraeger@xxxxxxxxxx;
> alifm@xxxxxxxxxxxxx
> Subject: [RFC v1 2/2] crypto/virtio-crypto: Register an algo only if it's supported
> 
> From: Farhan Ali <alifm@xxxxxxxxxxxxxxxxxx>
> 
> Register a crypto algo with the Linux crypto layer only if
> the algorithm is supported by the backend virtio-crypto
> device.
> 
> Also route crypto requests to a virtio-crypto
> device, only if it can support the requested service and
> algorithm.
> 
> Signed-off-by: Farhan Ali <alifm@xxxxxxxxxxxxx>
> ---
>  drivers/crypto/virtio/virtio_crypto_algs.c   | 110
> ++++++++++++++++++---------
>  drivers/crypto/virtio/virtio_crypto_common.h |  11 ++-
>  drivers/crypto/virtio/virtio_crypto_mgr.c    |  81 ++++++++++++++++++--
>  3 files changed, 158 insertions(+), 44 deletions(-)
> 
> diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c
> b/drivers/crypto/virtio/virtio_crypto_algs.c
> index ba190cf..fef112a 100644
> --- a/drivers/crypto/virtio/virtio_crypto_algs.c
> +++ b/drivers/crypto/virtio/virtio_crypto_algs.c
> @@ -49,12 +49,18 @@ struct virtio_crypto_sym_request {
>  	bool encrypt;
>  };
> 
> +struct virtio_crypto_algo {
> +	uint32_t algonum;
> +	uint32_t service;
> +	unsigned int active_devs;
> +	struct crypto_alg algo;
> +};
> +
>  /*
>   * The algs_lock protects the below global virtio_crypto_active_devs
>   * and crypto algorithms registion.
>   */
>  static DEFINE_MUTEX(algs_lock);
> -static unsigned int virtio_crypto_active_devs;
>  static void virtio_crypto_ablkcipher_finalize_req(
>  	struct virtio_crypto_sym_request *vc_sym_req,
>  	struct ablkcipher_request *req,
> @@ -312,13 +318,19 @@ static int virtio_crypto_ablkcipher_setkey(struct
> crypto_ablkcipher *tfm,
>  					 unsigned int keylen)
>  {
>  	struct virtio_crypto_ablkcipher_ctx *ctx = crypto_ablkcipher_ctx(tfm);
> +	uint32_t alg;
>  	int ret;
> 
> +	ret = virtio_crypto_alg_validate_key(keylen, &alg);
> +	if (ret)
> +		return ret;
> +
>  	if (!ctx->vcrypto) {
>  		/* New key */
>  		int node = virtio_crypto_get_current_node();
>  		struct virtio_crypto *vcrypto =
> -				      virtcrypto_get_dev_node(node);
> +				      virtcrypto_get_dev_node(node,
> +				      VIRTIO_CRYPTO_SERVICE_CIPHER, alg);
>  		if (!vcrypto) {
>  			pr_err("virtio_crypto: Could not find a virtio device in the
> system\n");

We'd better change the above error message now. What about:
 " virtio_crypto: Could not find a virtio device in the system or unsupported algo" ?

Regards,
-Gonglei