prov/efa: Add rdma-core errno for feature mismatch

Add proper error handling for when the peer doesn't support or
didn't enable a locally requested feature. This provides clearer
diagnostics instead of vague failures.

Reviewed-by: Michael Margolin <mrgolin@amazon.com>
Signed-off-by: Chen Brasch <cbrasch@amazon.com>

Author: chenbraschh

fabtests/prov/efa/src/efagda/efa_io_defs.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause */
 /*
- * Copyright 2018-2024 Amazon.com, Inc. or its affiliates. All rights reserved.
+ * Copyright 2018-2026 Amazon.com, Inc. or its affiliates. All rights reserved.
  */
 
 #ifndef _EFA_IO_H_
@@ -65,6 +65,8 @@ enum efa_io_comp_status {
 	EFA_IO_COMP_STATUS_REMOTE_ERROR_UNKNOWN_PEER = 14,
 	/* Unreachable remote - never received a response */
 	EFA_IO_COMP_STATUS_LOCAL_ERROR_UNREACH_REMOTE = 15,
+	/* Remote feature mismatch */
+	EFA_IO_COMP_STATUS_REMOTE_ERROR_FEATURE_MISMATCH = 18,
 };
 
 enum efa_io_frwr_pbl_mode {

prov/efa/src/efa_data_path_direct_internal.h

@@ -141,6 +141,7 @@ EFA_ALWAYS_INLINE enum ibv_wc_status to_ibv_status(enum efa_errno status)
 		return IBV_WC_REM_INV_RD_REQ_ERR;
 	case EFA_IO_COMP_STATUS_REMOTE_ERROR_BAD_STATUS:
 		return IBV_WC_BAD_RESP_ERR;
+	case EFA_IO_COMP_STATUS_REMOTE_ERROR_FEATURE_MISMATCH:
 	case EFA_IO_COMP_STATUS_REMOTE_ERROR_BAD_LENGTH:
 		return IBV_WC_REM_INV_REQ_ERR;
 	case EFA_IO_COMP_STATUS_LOCAL_ERROR_UNRESP_REMOTE:

prov/efa/src/efa_errno.h

@@ -71,7 +71,8 @@
 	_(12,	REMOTE_ERROR_BAD_STATUS,	Unexpected status returned by responder)					\
 	_(13,	LOCAL_ERROR_UNRESP_REMOTE,	Unresponsive remote (was previously responsive))						\
 	_(14,	REMOTE_ERROR_UNKNOWN_PEER,	No valid address handle at remote side (required for RDMA operations))	\
-	_(15,	LOCAL_ERROR_UNREACH_REMOTE,	Unreachable remote (never received a response))
+	_(15,	LOCAL_ERROR_UNREACH_REMOTE,	Unreachable remote - never received a response)					\
+	_(18,	REMOTE_ERROR_FEATURE_MISMATCH,	Remote feature mismatch)							\
 
 /**
  * @brief EFA provider proprietary error codes
@@ -157,6 +158,7 @@ static inline int to_fi_errno(enum efa_errno err) {
 	case EFA_IO_COMP_STATUS_LOCAL_ERROR_INVALID_LKEY:
 	case EFA_IO_COMP_STATUS_LOCAL_ERROR_UNSUPPORTED_OP:
 	case EFA_IO_COMP_STATUS_REMOTE_ERROR_BAD_ADDRESS:
+	case EFA_IO_COMP_STATUS_REMOTE_ERROR_FEATURE_MISMATCH:
 		return FI_EINVAL;
 	case EFA_IO_COMP_STATUS_LOCAL_ERROR_UNREACH_REMOTE:
 		return FI_EHOSTUNREACH;

prov/efa/src/efa_strerror.c

@@ -94,6 +94,10 @@ void efa_show_help(enum efa_errno err) {
 		"Please consider matching the local and remote libfabric versions, or turning off "
 		"the zero-copy recv feature by setting FI_EFA_USE_ZCPY_RX=0 in the environment";
 		break;
+	case EFA_IO_COMP_STATUS_REMOTE_ERROR_FEATURE_MISMATCH:
+		help = "This error is detected remotely. "
+		"The peer doesn't support or didn't enable a locally requested feature.";
+		break;
 	default:
 		return;
 	}