[dpdk-dev] [PATCH v2] ethdev: reserve space in main structs for extension

[Thomas Monjalon <thomas@monjalon.net>]

In order to allow smooth addition of features without breaking
ABI compatibility, some space is reserved in several core structs
of ethdev API.

The struct rte_eth_dev and rte_eth_dev_data are supposed
to be used internally only, but there is a chance that
increasing their size would break ABI for some applications.

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
---
v2: padding more struct (config and get_info)

Note: previous acks are not kept in order to request an explicit
review of these new changes.
---
 lib/librte_ethdev/rte_ethdev.h      | 15 +++++++++++++++
 lib/librte_ethdev/rte_ethdev_core.h |  6 ++++++
 2 files changed, 21 insertions(+)

diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
index 44d77b332e..4ba01905c5 100644
--- a/lib/librte_ethdev/rte_ethdev.h
+++ b/lib/librte_ethdev/rte_ethdev.h
@@ -402,6 +402,9 @@ struct rte_eth_rxmode {
 	 * structure are allowed to be set.
 	 */
 	uint64_t offloads;
+
+	uint64_t reserved_64s[2]; /**< Reserved for future fields */
+	void *reserved_ptrs[2];   /**< Reserved for future fields */
 };
 
 /**
@@ -802,6 +805,9 @@ struct rte_eth_txmode {
 		/**< If set, reject sending out untagged pkts */
 		hw_vlan_insert_pvid : 1;
 		/**< If set, enable port based VLAN insertion */
+
+	uint64_t reserved_64s[2]; /**< Reserved for future fields */
+	void *reserved_ptrs[2];   /**< Reserved for future fields */
 };
 
 /**
@@ -818,6 +824,9 @@ struct rte_eth_rxconf {
 	 * fields on rte_eth_dev_info structure are allowed to be set.
 	 */
 	uint64_t offloads;
+
+	uint64_t reserved_64s[2]; /**< Reserved for future fields */
+	void *reserved_ptrs[2];   /**< Reserved for future fields */
 };
 
 /**
@@ -836,6 +845,9 @@ struct rte_eth_txconf {
 	 * fields on rte_eth_dev_info structure are allowed to be set.
 	 */
 	uint64_t offloads;
+
+	uint64_t reserved_64s[2]; /**< Reserved for future fields */
+	void *reserved_ptrs[2];   /**< Reserved for future fields */
 };
 
 /**
@@ -1260,6 +1272,9 @@ struct rte_eth_dev_info {
 	 * embedded managed interconnect/switch.
 	 */
 	struct rte_eth_switch_info switch_info;
+
+	uint64_t reserved_64s[2]; /**< Reserved for future fields */
+	void *reserved_ptrs[2];   /**< Reserved for future fields */
 };
 
 /**
diff --git a/lib/librte_ethdev/rte_ethdev_core.h b/lib/librte_ethdev/rte_ethdev_core.h
index f215af7c94..4d52be6121 100644
--- a/lib/librte_ethdev/rte_ethdev_core.h
+++ b/lib/librte_ethdev/rte_ethdev_core.h
@@ -785,6 +785,9 @@ struct rte_eth_dev {
 	struct rte_eth_rxtx_callback *pre_tx_burst_cbs[RTE_MAX_QUEUES_PER_PORT];
 	enum rte_eth_dev_state state; /**< Flag indicating the port state */
 	void *security_ctx; /**< Context for security ops */
+
+	uint64_t reserved_64s[4]; /**< Reserved for future fields */
+	void *reserved_ptrs[4];   /**< Reserved for future fields */
 } __rte_cache_aligned;
 
 struct rte_eth_dev_sriov;
@@ -851,6 +854,9 @@ struct rte_eth_dev_data {
 			/**< Switch-specific identifier.
 			 *   Valid if RTE_ETH_DEV_REPRESENTOR in dev_flags.
 			 */
+
+	uint64_t reserved_64s[4]; /**< Reserved for future fields */
+	void *reserved_ptrs[4];   /**< Reserved for future fields */
 } __rte_cache_aligned;
 
 /**
-- 
2.23.0