DAOS-16935 cart: add D_MEM_DEVICE and cio_mem_device init option (#15937)

This enables the detection and use of memory devices for RMA transfers

Clean up cart init info print

Consolidate parsing of cart init options

Signed-off-by: Jerome Soumagne <[email protected]>

Author: soumagne

src/cart/README.env

@@ -226,3 +226,8 @@ This file lists the environment variables used in CaRT.
    D_PROGRESS_BUSY
    Force busy polling when progressing, preventing from sleeping when waiting for
    new messages.
+
+   D_MEM_DEVICE
+   Enable detection and use of memory devices (GPU, etc) to perform RMA transfers to/from.
+   Be wary of potential performance impacts if this variable is set and memory devices
+   are not used.

src/cart/crt_hg.c

@@ -1,7 +1,7 @@
 /*
  * (C) Copyright 2016-2024 Intel Corporation.
  * (C) Copyright 2025 Google LLC
- * (C) Copyright 2025 Hewlett Packard Enterprise Development LP
+ * (C) Copyright 2025-2026 Hewlett Packard Enterprise Development LP
  *
  * SPDX-License-Identifier: BSD-2-Clause-Patent
  */
@@ -846,7 +846,7 @@ crt_hg_class_init(crt_provider_t provider, int ctx_idx, bool primary, int iface_
 
 	init_info.na_init_info.auth_key = prov_data->cpg_na_config.noc_auth_key;
 
-	if (crt_provider_is_block_mode(provider) && !prov_data->cpg_progress_busy)
+	if (crt_provider_is_block_mode(provider) && !crt_gdata.cg_progress_busy)
 		init_info.na_init_info.progress_mode = 0;
 	else
 		init_info.na_init_info.progress_mode = NA_NO_BLOCK;
@@ -872,6 +872,7 @@ crt_hg_class_init(crt_provider_t provider, int ctx_idx, bool primary, int iface_
 		init_info.traffic_class = (enum na_traffic_class)crt_gdata.cg_swim_tc;
 	if (thread_mode_single)
 		init_info.na_init_info.thread_mode = NA_THREAD_MODE_SINGLE;
+	init_info.na_init_info.request_mem_device = crt_gdata.cg_mem_device;
 retry:
 	hg_class = HG_Init_opt2(info_string, crt_is_service(), HG_VERSION(2, 4), &init_info);
 	if (hg_class == NULL) {