Re: [dpdk-dev] [PATCH v2 4/6] bond mode 4: allow external state machine

[Panu Matilainen <pmatilai@redhat.com>]

On 02/19/2016 09:17 PM, Eric Kinzie wrote:
> From: Eric Kinzie <ekinzie@brocade.com>
>
> Provide functions to allow an external 802.3ad state machine to transmit
> and recieve LACPDUs and to set the collection/distribution flags on
> slave interfaces.
>
> Signed-off-by: Eric Kinzie <ehkinzie@gmail.com>
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> Acked-by: Declan Doherty <declan.doherty@intel.com>
[...]
> diff --git a/drivers/net/bonding/rte_eth_bond_8023ad.h b/drivers/net/bonding/rte_eth_bond_8023ad.h
> index ebd0e93..8cfa3d3 100644
> --- a/drivers/net/bonding/rte_eth_bond_8023ad.h
> +++ b/drivers/net/bonding/rte_eth_bond_8023ad.h
> @@ -64,6 +64,8 @@ extern "C" {
>   #define MARKER_TLV_TYPE_INFO                0x01
>   #define MARKER_TLV_TYPE_RESP                0x02
>
> +typedef void (*rte_eth_bond_8023ad_ext_slowrx_fn)(uint8_t slave_id, struct rte_mbuf *lacp_pkt);
> +
>   enum rte_bond_8023ad_selection {
>   	UNSELECTED,
>   	STANDBY,
> @@ -157,6 +159,7 @@ struct rte_eth_bond_8023ad_conf {
>   	uint32_t tx_period_ms;
>   	uint32_t rx_marker_period_ms;
>   	uint32_t update_timeout_ms;
> +	rte_eth_bond_8023ad_ext_slowrx_fn slowrx_cb;
>   };

This still is a likely an ABI break, previously discussed around here:
http://dpdk.org/ml/archives/dev/2015-November/027321.html

It might not be embedded anywhere in DPDK codebase, but there's no 
telling what others might have done with it (have an array of them, 
embed in other structs etc).

Also ultimately ABI compatibility goes both ways: when the library 
soname does not change then an application is free to assume both 
downgrading and upgrading are safe. In this case, upgrading *might* be 
okay, downgrading certainly is not. So by that measure it definitely is 
an ABI break.

[...]
> diff --git a/drivers/net/bonding/rte_eth_bond_version.map b/drivers/net/bonding/rte_eth_bond_version.map
> index 22bd920..33d73ff 100644
> --- a/drivers/net/bonding/rte_eth_bond_version.map
> +++ b/drivers/net/bonding/rte_eth_bond_version.map
> @@ -27,3 +27,9 @@ DPDK_2.1 {
>   	rte_eth_bond_free;
>
>   } DPDK_2.0;
> +
> +DPDK_2.2 {
> +	rte_eth_bond_8023ad_ext_collect;
> +	rte_eth_bond_8023ad_ext_distrib;
> +	rte_eth_bond_8023ad_ext_slowtx;
> +} DPDK_2.1;
>

These symbols are not part of DPDK 2.2, the version here is wrong. 
Technically it would not actually matter much but better not to confuse 
things unnecessarily.

	- Panu -