Re: [PATCH v23 07/20] nvme-tcp: RX DDGST offload

Sagi Grimberg
2024-03-07T09:18:15Z

On 28/02/2024 14:57, Aurelien Aptel wrote:
> From: Yoray Zack <yorayz@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@nvidia.com>
> Signed-off-by: Boris Pismenny <borisp@nvidia.com>
> Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
> Signed-off-by: Or Gerlitz <ogerlitz@nvidia.com>
> Signed-off-by: Shai Malin <smalin@nvidia.com>
> Signed-off-by: Aurelien Aptel <aaptel@nvidia.com>
> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
> ---
> drivers/nvme/host/tcp.c | 96 ++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 91 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
> index b7cfe14661d6..2eebd9d2aee5 100644
> --- a/drivers/nvme/host/tcp.c
> +++ b/drivers/nvme/host/tcp.c
> @@ -143,6 +143,7 @@ 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 {
> @@ -180,6 +181,7 @@ struct nvme_tcp_queue {
> * is pending (ULP_DDP_RESYNC_PENDING).
> */
> atomic64_t resync_tcp_seq;
> + bool ddp_ddgst_valid;
> #endif
>
> /* send state */
> @@ -393,6 +395,46 @@ nvme_tcp_get_ddp_netdev_with_limits(struct nvme_tcp_ctrl *ctrl)
> return NULL;
> }
>
> +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;
> +
> + req = blk_mq_rq_to_pdu(rq);
> + if (!req->offloaded) {
> + /* if we have DDGST_RX offload but DDP was skipped
> + * because it's under the min IO threshold then the
> + * request won't have an SGL, so we need to make it
> + * here
> + */
> + if (nvme_tcp_ddp_alloc_sgl(req, rq))
> + return;
> + }
> +
> + ahash_request_set_crypt(hash, req->ddp.sg_table.sgl, (u8 *)ddgst,
> + req->data_len);
> + crypto_ahash_digest(hash);
> + if (!req->offloaded) {
> + /* without DDP, ddp_teardown() won't be called, so
> + * free the table here
> + */
> + sg_free_table_chained(&req->ddp.sg_table, SG_CHUNK_SIZE);
> + }
> +}
> +
> 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 = {
> @@ -478,6 +520,10 @@ static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
> return ret;
>
> set_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
> + if (queue->data_digest &&
> + ulp_ddp_is_cap_active(queue->ctrl->ddp_netdev,
> + ULP_DDP_CAP_NVME_TCP_DDGST_RX))
> + set_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags);
>
> return 0;
> }
> @@ -485,6 +531,7 @@ static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
> static void nvme_tcp_unoffload_socket(struct nvme_tcp_queue *queue)
> {
> clear_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
> + clear_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags);
> ulp_ddp_sk_del(queue->ctrl->ddp_netdev, queue->sock->sk);
> }
>
> @@ -593,6 +640,20 @@ static void nvme_tcp_resync_response(struct nvme_tcp_queue *queue,
> struct sk_buff *skb, unsigned int offset)
> {}
>
> +static inline bool nvme_tcp_ddp_ddgst_ok(struct nvme_tcp_queue *queue)
> +{
> + return false;
> +}
> +
> +static inline void nvme_tcp_ddp_ddgst_update(struct nvme_tcp_queue *queue,
> + struct sk_buff *skb)
> +{}
> +
> +static void nvme_tcp_ddp_ddgst_recalc(struct ahash_request *hash,
> + struct request *rq,
> + __le32 *ddgst)
> +{}
> +
> #endif
>
> static void nvme_tcp_init_iter(struct nvme_tcp_request *req,
> @@ -853,6 +914,9 @@ static void nvme_tcp_init_recv_ctx(struct nvme_tcp_queue *queue)
> queue->pdu_offset = 0;
> queue->data_remaining = -1;
> queue->ddgst_remaining = 0;
> +#ifdef CONFIG_ULP_DDP
> + queue->ddp_ddgst_valid = true;
> +#endif
> }
>
> static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl)
> @@ -1118,6 +1182,9 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
> nvme_cid_to_rq(nvme_tcp_tagset(queue), pdu->command_id);
> struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
>
> + if (test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
> + nvme_tcp_ddp_ddgst_update(queue, skb);
> +
> while (true) {
> int recv_len, ret;
>
> @@ -1146,7 +1213,8 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
> recv_len = min_t(size_t, recv_len,
> iov_iter_count(&req->iter));
>
> - if (queue->data_digest)
> + if (queue->data_digest &&
> + !test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
> ret = skb_copy_and_hash_datagram_iter(skb, *offset,
> &req->iter, recv_len, queue->rcv_hash);
> else
> @@ -1188,8 +1256,11 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue,
> char *ddgst = (char *)&queue->recv_ddgst;
> size_t recv_len = min_t(size_t, *len, queue->ddgst_remaining);
> off_t off = NVME_TCP_DIGEST_LENGTH - queue->ddgst_remaining;
> + struct request *rq;
> int ret;
>
> + if (test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
> + nvme_tcp_ddp_ddgst_update(queue, skb);
> ret = skb_copy_bits(skb, *offset, &ddgst[off], recv_len);
> if (unlikely(ret))
> return ret;
> @@ -1200,9 +1271,25 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue,
> if (queue->ddgst_remaining)
> return 0;
>
> + rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
> + pdu->command_id);
> +
> + if (test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags)) {
> + /*
> + * If HW successfully offloaded the digest
> + * verification, we can skip it
> + */
> + if (nvme_tcp_ddp_ddgst_ok(queue))
> + goto out;
> + /*
> + * Otherwise we have to recalculate and verify the
> + * digest with the software-fallback
> + */
> + nvme_tcp_ddp_ddgst_recalc(queue->rcv_hash, rq,
> + &queue->exp_ddgst);
> + }
> +
> if (queue->recv_ddgst != queue->exp_ddgst) {
> - struct request *rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
> - pdu->command_id);
> struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
>
> req->status = cpu_to_le16(NVME_SC_DATA_XFER_ERROR);
> @@ -1213,9 +1300,8 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue,
> le32_to_cpu(queue->exp_ddgst));
> }
>
> +out:

Nit: you can rename the label to ddgst_valid: or ddgst_ok:

Other than that,
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>