[PATCH v5 net-next 06/36] nvme-tcp: Add DDP data-path
From: Boris Pismenny <borisp@nvidia.com>
Date: 2021-07-22 11:06:49
Also in:
netdev
Subsystem:
nvm express driver, the rest · Maintainers:
Keith Busch, Jens Axboe, Christoph Hellwig, Sagi Grimberg, Linus Torvalds
From: Boris Pismenny <redacted> Introduce the NVMe-TCP DDP data-path offload. Using this interface, the NIC hardware will scatter TCP payload directly to the BIO pages according to the command_id in the PDU. To maintain the correctness of the network stack, the driver is expected to construct SKBs that point to the BIO pages. The data-path interface contains two routines: tcp_ddp_setup/teardown. The setup provides the mapping from command_id to the request buffers, while the teardown removes this mapping. For efficiency, we introduce an asynchronous nvme completion, which is split between NVMe-TCP and the NIC driver as follows: NVMe-TCP performs the specific completion, while NIC driver performs the generic mq_blk completion. Signed-off-by: Boris Pismenny <redacted> Signed-off-by: Ben Ben-Ishay <redacted> Signed-off-by: Or Gerlitz <redacted> Signed-off-by: Yoray Zack <redacted> --- drivers/nvme/host/tcp.c | 150 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 138 insertions(+), 12 deletions(-)
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index f1a5520cabec..34982fb0c655 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c@@ -57,6 +57,11 @@ struct nvme_tcp_request { size_t offset; size_t data_sent; enum nvme_tcp_send_state state; + + bool offloaded; + struct ulp_ddp_io ddp; + __le16 status; + union nvme_result result; }; enum nvme_tcp_queue_flags {
@@ -225,13 +230,76 @@ static inline size_t nvme_tcp_pdu_last_send(struct nvme_tcp_request *req, return nvme_tcp_pdu_data_left(req) <= len; } +static int nvme_tcp_req_map_sg(struct nvme_tcp_request *req, struct request *rq) +{ + int ret; + + req->ddp.sg_table.sgl = req->ddp.first_sgl; + ret = sg_alloc_table_chained(&req->ddp.sg_table, blk_rq_nr_phys_segments(rq), + req->ddp.sg_table.sgl, SG_CHUNK_SIZE); + if (ret) + return -ENOMEM; + req->ddp.nents = blk_rq_map_sg(rq->q, rq, req->ddp.sg_table.sgl); + return 0; +} + #ifdef CONFIG_ULP_DDP 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 = { .resync_request = nvme_tcp_resync_request, + .ddp_teardown_done = nvme_tcp_ddp_teardown_done, }; +static int nvme_tcp_teardown_ddp(struct nvme_tcp_queue *queue, + u16 command_id, + struct request *rq) +{ + struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq); + struct net_device *netdev = queue->ctrl->offloading_netdev; + int ret; + + ret = netdev->ulp_ddp_ops->ulp_ddp_teardown(netdev, queue->sock->sk, + &req->ddp, rq); + sg_free_table_chained(&req->ddp.sg_table, SG_CHUNK_SIZE); + return ret; +} + +static void nvme_tcp_ddp_teardown_done(void *ddp_ctx) +{ + struct request *rq = ddp_ctx; + struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq); + + if (!nvme_try_complete_req(rq, req->status, req->result)) + nvme_complete_rq(rq); +} + +static int nvme_tcp_setup_ddp(struct nvme_tcp_queue *queue, + u16 command_id, + struct request *rq) +{ + struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq); + struct net_device *netdev = queue->ctrl->offloading_netdev; + int ret; + + if (!test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags) || + !blk_rq_nr_phys_segments(rq) || !(rq_data_dir(rq) == READ)) + return -EINVAL; + + req->ddp.command_id = command_id; + ret = nvme_tcp_req_map_sg(req, rq); + if (ret) + return -ENOMEM; + + ret = netdev->ulp_ddp_ops->ulp_ddp_setup(netdev, + queue->sock->sk, + &req->ddp); + if (!ret) + req->offloaded = true; + return ret; +} + static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue) { struct net_device *netdev = queue->ctrl->offloading_netdev;
@@ -342,7 +410,7 @@ static void nvme_tcp_resync_response(struct nvme_tcp_queue *queue, return; if (unlikely(!netdev)) { - pr_info_ratelimited("%s: netdev not found\n", __func__); + dev_info_ratelimited(queue->ctrl->ctrl.device, "netdev not found\n"); return; }
@@ -367,6 +435,20 @@ static bool nvme_tcp_resync_request(struct sock *sk, u32 seq, u32 flags) #else +static int nvme_tcp_setup_ddp(struct nvme_tcp_queue *queue, + u16 command_id, + struct request *rq) +{ + return -EINVAL; +} + +static int nvme_tcp_teardown_ddp(struct nvme_tcp_queue *queue, + u16 command_id, + struct request *rq) +{ + return -EINVAL; +} + static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue) { return -EINVAL;
@@ -650,6 +732,24 @@ static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl) queue_work(nvme_reset_wq, &to_tcp_ctrl(ctrl)->err_work); } +static void nvme_tcp_complete_request(struct request *rq, + __le16 status, + union nvme_result result, + __u16 command_id) +{ + struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq); + struct nvme_tcp_queue *queue = req->queue; + + if (req->offloaded) { + req->status = status; + req->result = result; + nvme_tcp_teardown_ddp(queue, command_id, rq); + } else { + if (!nvme_try_complete_req(rq, status, result)) + nvme_complete_rq(rq); + } +} + static int nvme_tcp_process_nvme_cqe(struct nvme_tcp_queue *queue, struct nvme_completion *cqe) {
@@ -664,10 +764,8 @@ static int nvme_tcp_process_nvme_cqe(struct nvme_tcp_queue *queue, return -EINVAL; } - if (!nvme_try_complete_req(rq, cqe->status, cqe->result)) - nvme_complete_rq(rq); + nvme_tcp_complete_request(rq, cqe->status, cqe->result, cqe->command_id); queue->nr_cqe++; - return 0; }
@@ -863,10 +961,39 @@ static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, struct sk_buff *skb, static inline void nvme_tcp_end_request(struct request *rq, u16 status) { + struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq); + struct nvme_tcp_queue *queue = req->queue; + struct nvme_tcp_data_pdu *pdu = (void *)queue->pdu; union nvme_result res = {}; - if (!nvme_try_complete_req(rq, cpu_to_le16(status << 1), res)) - nvme_complete_rq(rq); + nvme_tcp_complete_request(rq, cpu_to_le16(status << 1), res, pdu->command_id); +} + + +static int nvme_tcp_consume_skb(struct nvme_tcp_queue *queue, struct sk_buff *skb, + unsigned int *offset, struct iov_iter *iter, int recv_len) +{ + int ret; + +#ifdef CONFIG_ULP_DDP + if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags)) { + if (queue->data_digest) + ret = skb_ddp_copy_and_hash_datagram_iter(skb, *offset, iter, recv_len, + queue->rcv_hash); + else + ret = skb_ddp_copy_datagram_iter(skb, *offset, iter, recv_len); + } else { +#endif + if (queue->data_digest) + ret = skb_copy_and_hash_datagram_iter(skb, *offset, iter, recv_len, + queue->rcv_hash); + else + ret = skb_copy_datagram_iter(skb, *offset, iter, recv_len); +#ifdef CONFIG_ULP_DDP + } +#endif + + return ret; } static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
@@ -913,12 +1040,7 @@ 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) - ret = skb_copy_and_hash_datagram_iter(skb, *offset, - &req->iter, recv_len, queue->rcv_hash); - else - ret = skb_copy_datagram_iter(skb, *offset, - &req->iter, recv_len); + ret = nvme_tcp_consume_skb(queue, skb, offset, &req->iter, recv_len); if (ret) { dev_err(queue->ctrl->ctrl.device, "queue %d failed to copy request %#x data",
@@ -1142,6 +1264,7 @@ static int nvme_tcp_try_send_cmd_pdu(struct nvme_tcp_request *req) bool inline_data = nvme_tcp_has_inline_data(req); u8 hdgst = nvme_tcp_hdgst_len(queue); int len = sizeof(*pdu) + hdgst - req->offset; + struct request *rq = blk_mq_rq_from_pdu(req); int flags = MSG_DONTWAIT; int ret;
@@ -1150,6 +1273,8 @@ static int nvme_tcp_try_send_cmd_pdu(struct nvme_tcp_request *req) else flags |= MSG_EOR; + nvme_tcp_setup_ddp(queue, pdu->cmd.common.command_id, rq); + if (queue->hdr_digest && !req->offset) nvme_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
@@ -2486,6 +2611,7 @@ static blk_status_t nvme_tcp_setup_cmd_pdu(struct nvme_ns *ns, if (req->curr_bio && req->data_len) nvme_tcp_init_iter(req, rq_data_dir(rq)); + req->offloaded = false; if (rq_data_dir(rq) == WRITE && req->data_len <= nvme_tcp_inline_data_size(queue)) req->pdu_len = req->data_len;
--
2.24.1
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