[PATCH v20 07/20] nvme-tcp: RX DDGST offload

[Sagi Grimberg]

On 11/22/23 15:48, Aurelien Aptel wrote:
> From: Yoray Zack <yorayz at nvidia.com>
> 
> Enable rx side of DDGST offload when supported.
> 
> At the end of the capsule, check if all the skb bits are on, and if not
> recalculate the DDGST in SW and check it.
> 
> Signed-off-by: Yoray Zack <yorayz at nvidia.com>
> Signed-off-by: Boris Pismenny <borisp at nvidia.com>
> Signed-off-by: Ben Ben-Ishay <benishay at nvidia.com>
> Signed-off-by: Or Gerlitz <ogerlitz at nvidia.com>
> Signed-off-by: Shai Malin <smalin at nvidia.com>
> Signed-off-by: Aurelien Aptel <aaptel at nvidia.com>
> Reviewed-by: Chaitanya Kulkarni <kch at nvidia.com>
> ---
>   drivers/nvme/host/tcp.c | 84 ++++++++++++++++++++++++++++++++++++++---
>   1 file changed, 79 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
> index 680d909eb3fb..5537f04a62fd 100644
> --- a/drivers/nvme/host/tcp.c
> +++ b/drivers/nvme/host/tcp.c
> @@ -141,6 +141,7 @@ enum nvme_tcp_queue_flags {
>   	NVME_TCP_Q_LIVE		= 1,
>   	NVME_TCP_Q_POLLING	= 2,
>   	NVME_TCP_Q_OFF_DDP	= 3,
> +	NVME_TCP_Q_OFF_DDGST_RX = 4,
>   };
>   
>   enum nvme_tcp_recv_state {
> @@ -178,6 +179,7 @@ struct nvme_tcp_queue {
>   	 *   is pending (ULP_DDP_RESYNC_PENDING).
>   	 */
>   	atomic64_t		resync_tcp_seq;
> +	bool			ddp_ddgst_valid;
>   #endif
>   
>   	/* send state */
> @@ -360,6 +362,33 @@ nvme_tcp_get_ddp_netdev_with_limits(struct nvme_tcp_ctrl *ctrl)
>   	return netdev;
>   }
>   
> +static inline bool nvme_tcp_ddp_ddgst_ok(struct nvme_tcp_queue *queue)
> +{
> +	return queue->ddp_ddgst_valid;
> +}
> +
> +static inline void nvme_tcp_ddp_ddgst_update(struct nvme_tcp_queue *queue,
> +					     struct sk_buff *skb)
> +{
> +	if (queue->ddp_ddgst_valid)
> +		queue->ddp_ddgst_valid = skb_is_ulp_crc(skb);
> +}
> +
> +static void nvme_tcp_ddp_ddgst_recalc(struct ahash_request *hash,
> +				      struct request *rq,
> +				      __le32 *ddgst)
> +{
> +	struct nvme_tcp_request *req;
> +
> +	if (!rq)
> +		return;

How is this even possible? And what happens down the road if this is
indeed a null rq?

> +
> +	req = blk_mq_rq_to_pdu(rq);
> +	ahash_request_set_crypt(hash, req->ddp.sg_table.sgl, (u8 *)ddgst,
> +				req->data_len);
> +	crypto_ahash_digest(hash);
> +}
> +
>   static bool nvme_tcp_resync_request(struct sock *sk, u32 seq, u32 flags);
>   static void nvme_tcp_ddp_teardown_done(void *ddp_ctx);
>   static const struct ulp_ddp_ulp_ops nvme_tcp_ddp_ulp_ops = {
> @@ -430,6 +459,8 @@ static void nvme_tcp_setup_ddp(struct nvme_tcp_queue *queue,
>   static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
>   {
>   	struct ulp_ddp_config config = {.type = ULP_DDP_NVME};
> +	bool offload_ddgst_rx = ulp_ddp_is_cap_active(queue->ctrl->ddp_netdev,
> +						      ULP_DDP_CAP_NVME_TCP_DDGST_RX);

Not sure a local variable is needed here.