[PATCH v2 4/4] ethdev: fix promoted flow metadata symbols

[Dariusz Sosnowski <dsosnowski@nvidia.com>]

Offending commit stabilized the following symbols
related to flow metadata:

- 1 function symbol:
    - rte_flow_dynf_metadata_register
- 2 variable symbols:
    - rte_flow_dynf_metadata_offs
    - rte_flow_dynf_metadata_mask

Any application using experimental flow metadata symbols,
which was linked dynamically against 25.11 version of ethdev
library and using current version of ethdev library
would fail to start on symbol lookup error:

/tmp/dpdk-25.11/usr/local/bin/dpdk-testpmd:
  symbol lookup error: /tmp/dpdk-25.11/usr/local/bin/dpdk-testpmd:
    undefined symbol: rte_flow_dynf_metadata_offs, version EXPERIMENTAL

This patch addresses that issue by restoring EXPERIMENTAL version
on the global variables to keep ABI compatibility [1].
Related inline helpers and variable declarations are kept as stable
(i.e., no __rte_experimental marker).
EXPERIMENTAL version will be removed from these global variables
in 26.11 release cycle on next ABI version bump.

Standard function symbol versioning is also applied on
rte_flow_dynf_metadata_register() function.

[1]: https://inbox.dpdk.org/dev/m7s3jl2566kibbapr2mfa2ic2opuc6b4ok2g67j3il5dgduzih@cz5wcdstb75n/

Bugzilla ID: 1957
Fixes: 4ee2f5c1cedf ("ethdev: promote flow metadata API to stable")

Reported-by: Yu Jiang <yux.jiang@intel.com>
Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
---
 lib/ethdev/meson.build |  2 ++
 lib/ethdev/rte_flow.c  | 13 ++++++++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/lib/ethdev/meson.build b/lib/ethdev/meson.build
index 8ba6c708a2..63fd866af9 100644
--- a/lib/ethdev/meson.build
+++ b/lib/ethdev/meson.build
@@ -1,6 +1,8 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright(c) 2017 Intel Corporation
 
+use_function_versioning = true
+
 sources = files(
         'ethdev_driver.c',
         'ethdev_private.c',
diff --git a/lib/ethdev/rte_flow.c b/lib/ethdev/rte_flow.c
index ec0fe08355..24eb5a95b0 100644
--- a/lib/ethdev/rte_flow.c
+++ b/lib/ethdev/rte_flow.c
@@ -23,11 +23,11 @@
 #define FLOW_LOG RTE_ETHDEV_LOG_LINE
 
 /* Mbuf dynamic field name for metadata. */
-RTE_EXPORT_SYMBOL(rte_flow_dynf_metadata_offs)
+RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_flow_dynf_metadata_offs, 19.11)
 int32_t rte_flow_dynf_metadata_offs = -1;
 
 /* Mbuf dynamic field flag bit number for metadata. */
-RTE_EXPORT_SYMBOL(rte_flow_dynf_metadata_mask)
+RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_flow_dynf_metadata_mask, 19.11)
 uint64_t rte_flow_dynf_metadata_mask;
 
 /**
@@ -281,9 +281,7 @@ static const struct rte_flow_desc_data rte_flow_desc_action[] = {
 	MK_FLOW_ACTION(JUMP_TO_TABLE_INDEX, sizeof(struct rte_flow_action_jump_to_table_index)),
 };
 
-RTE_EXPORT_SYMBOL(rte_flow_dynf_metadata_register)
-int
-rte_flow_dynf_metadata_register(void)
+RTE_DEFAULT_SYMBOL(26, int, rte_flow_dynf_metadata_register, (void))
 {
 	int offset;
 	int flag;
@@ -316,6 +314,11 @@ rte_flow_dynf_metadata_register(void)
 	return -rte_errno;
 }
 
+RTE_VERSION_EXPERIMENTAL_SYMBOL(int, rte_flow_dynf_metadata_register, (void))
+{
+	return rte_flow_dynf_metadata_register();
+}
+
 static inline void
 fts_enter(struct rte_eth_dev *dev)
 {
-- 
2.47.3