net/mlx5: support enhanced multi-packet write on Windows

Add support for enhanced multi-packet write on Windows.

Enhanced multi-packet write allows the Tx burst function to pack up
multiple packets in a single descriptor session to save PCI bandwidth
and improve performance.

The feature can be controlled by the txq_mpw_en PMD argument:

txq_mpw_en=1 - PMD will first attempt to use "enhanced multi packet write"
if the feature is not supported by the HW the legacy "multi packet write"
will be used.
if both are unsupported the multi packet write feature is disabled.

txq_mpw_en=0 - multi packet write is disabled.

txq_mpw_en unset(default) - enhanced multi packet write
will be activated if supported.
if unsupported the multi packet write feature is disabled.

Signed-off-by: Tal Shnaiderman <talshn@nvidia.com>
Signed-off-by: 0-day Robot <robot@bytheb.org>

doc/guides/rel_notes/release_23_07.rst

@@ -24,36 +24,11 @@ DPDK Release 23.07
 New Features
 ------------
 
-.. This section should contain new features added in this release.
-   Sample format:
+* **Updated NVIDIA mlx5 driver.**
 
-   * **Add a title in the past tense with a full stop.**
-
-     Add a short 1-2 sentence description in the past tense.
-     The description should be enough to allow someone scanning
-     the release notes to understand the new feature.
-
-     If the feature adds a lot of sub-features you can use a bullet list
-     like this:
-
-     * Added feature foo to do something.
-     * Enhanced feature bar to do something else.
-
-     Refer to the previous release notes for examples.
-
-     Suggested order in release notes items:
-     * Core libs (EAL, mempool, ring, mbuf, buses)
-     * Device abstraction libs and PMDs (ordered alphabetically by vendor name)
-       - ethdev (lib, PMDs)
-       - cryptodev (lib, PMDs)
-       - eventdev (lib, PMDs)
-       - etc
-     * Other libs
-     * Apps, Examples, Tools (if significant)
-
-     This section is a comment. Do not overwrite or remove it.
-     Also, make sure to start the actual text at the margin.
-     =======================================================
+  * Added support for multi-packet RQ on Windows.
+  * Added support for CQE compression on Windows.
+  * Added support for enhanced multi-packet write on Windows.
 
 
 Removed Items

drivers/common/mlx5/mlx5_devx_cmds.c

@@ -1298,6 +1298,12 @@ mlx5_devx_cmd_query_hca_attr(void *ctx,
 	attr->rss_ind_tbl_cap = MLX5_GET
 					(per_protocol_networking_offload_caps,
 					 hcattr, rss_ind_tbl_cap);
+	attr->multi_pkt_send_wqe = MLX5_GET
+					(per_protocol_networking_offload_caps,
+					 hcattr, multi_pkt_send_wqe);
+	attr->enhanced_multi_pkt_send_wqe = MLX5_GET
+					(per_protocol_networking_offload_caps,
+					 hcattr, enhanced_multi_pkt_send_wqe);
 	/* Query HCA attribute for ROCE. */
 	if (attr->roce) {
 		hcattr = mlx5_devx_get_hca_cap(ctx, in, out, &rc,

drivers/common/mlx5/mlx5_devx_cmds.h

@@ -285,6 +285,8 @@ struct mlx5_hca_attr {
 	uint32_t striding_rq:1;
 	uint32_t ext_stride_num_range:1;
 	uint32_t cqe_compression_128:1;
+	uint32_t multi_pkt_send_wqe:1;
+	uint32_t enhanced_multi_pkt_send_wqe:1;
 	uint32_t set_reg_c:8;
 	uint32_t nic_flow_table:1;
 	uint32_t modify_outer_ip_ecn:1;

drivers/net/mlx5/windows/mlx5_os.c

@@ -173,7 +173,6 @@ mlx5_os_capabilities_prepare(struct mlx5_dev_ctx_shared *sh)
 	sh->dev_cap.max_qp = 1 << hca_attr->log_max_qp;
 	sh->dev_cap.max_qp_wr = 1 << hca_attr->log_max_qp_sz;
 	sh->dev_cap.dv_flow_en = 1;
-	sh->dev_cap.mps = MLX5_MPW_DISABLED;
 	DRV_LOG(DEBUG, "MPW isn't supported.");
 	DRV_LOG(DEBUG, "MPLS over GRE/UDP tunnel offloading is no supported.");
 	sh->dev_cap.hw_csum = hca_attr->csum_cap;
@@ -224,6 +223,13 @@ mlx5_os_capabilities_prepare(struct mlx5_dev_ctx_shared *sh)
 		DRV_LOG(DEBUG, "Maximum Rx indirection table size is %u",
 			sh->dev_cap.ind_table_max_size);
 	}
+	if (hca_attr->enhanced_multi_pkt_send_wqe)
+		sh->dev_cap.mps = MLX5_MPW_ENHANCED;
+	else if (hca_attr->multi_pkt_send_wqe &&
+		 sh->dev_cap.mps != MLX5_ARG_UNSET)
+		sh->dev_cap.mps = MLX5_MPW;
+	else
+		sh->dev_cap.mps = MLX5_MPW_DISABLED;
 	sh->dev_cap.swp = mlx5_get_supported_sw_parsing_offloads(hca_attr);
 	sh->dev_cap.tunnel_en = mlx5_get_supported_tunneling_offloads(hca_attr);
 	if (sh->dev_cap.tunnel_en) {