Re: [PATCH] lib: add get/set link settings interface

[David Marchand <david.marchand@redhat.com>]

Hello Tyler, Marek,

On Wed, Apr 3, 2024 at 6:49 PM Tyler Retzlaff
<roretzla@linux.microsoft.com> wrote:
>
> On Wed, Apr 03, 2024 at 06:40:24AM -0700, Marek Pazdan wrote:
> >  There are link settings parameters available from PMD drivers level
> >  which are currently not exposed to the user via consistent interface.
> >  When interface is available for system level those information can
> >  be acquired with 'ethtool DEVNAME' (ioctl: ETHTOOL_SLINKSETTINGS/
> >  ETHTOOL_GLINKSETTINGS). There are use cases where
> >  physical interface is passthrough to dpdk driver and is not available
> >  from system level. Information provided by ioctl carries information
> >  useful for link auto negotiation settings among others.
> >
> > Signed-off-by: Marek Pazdan <mpazdan@arista.com>
> > ---
> > diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
> > index 147257d6a2..66aad925d0 100644
> > --- a/lib/ethdev/rte_ethdev.h
> > +++ b/lib/ethdev/rte_ethdev.h
> > @@ -335,7 +335,7 @@ struct rte_eth_stats {
> >  __extension__
> >  struct __rte_aligned(8) rte_eth_link { /**< aligned for atomic64 read/write */
> >       uint32_t link_speed;        /**< RTE_ETH_SPEED_NUM_ */
> > -     uint16_t link_duplex  : 1;  /**< RTE_ETH_LINK_[HALF/FULL]_DUPLEX */
> > +     uint16_t link_duplex  : 2;  /**< RTE_ETH_LINK_[HALF/FULL/UNKNOWN]_DUPLEX */
> >       uint16_t link_autoneg : 1;  /**< RTE_ETH_LINK_[AUTONEG/FIXED] */
> >       uint16_t link_status  : 1;  /**< RTE_ETH_LINK_[DOWN/UP] */
> >  };
>
> this breaks the abi. David does libabigail pick this up i wonder?
>

Yes, the CI flagged it.

Looking at the UNH report (in patchwork):
http://mails.dpdk.org/archives/test-report/2024-April/631222.html

1 function with some indirect sub-type change:

[C] 'function int rte_eth_link_get(uint16_t, rte_eth_link*)' at
rte_ethdev.c:2972:1 has some indirect sub-type changes:
parameter 2 of type 'rte_eth_link*' has sub-type changes:
in pointed to type 'struct rte_eth_link' at rte_ethdev.h:336:1:
type size hasn't changed
2 data member changes:
'uint16_t link_autoneg' offset changed from 33 to 34 (in bits) (by +1 bits)
'uint16_t link_status' offset changed from 34 to 35 (in bits) (by +1 bits)

Error: ABI issue reported for abidiff --suppr
/home-local/jenkins-local/jenkins-agent/workspace/Generic-DPDK-Compile-ABI
at 3/dpdk/devtools/libabigail.abignore --no-added-syms --headers-dir1
reference/usr/local/include --headers-dir2
build_install/usr/local/include
reference/usr/local/lib/x86_64-linux-gnu/librte_ethdev.so.24.0
build_install/usr/local/lib/x86_64-linux-gnu/librte_ethdev.so.24.2
ABIDIFF_ABI_CHANGE, this change requires a review (abidiff flagged
this as a potential issue).


GHA would have caught it too, but the documentation generation failed
before reaching the ABI check.
http://mails.dpdk.org/archives/test-report/2024-April/631086.html


-- 
David Marchand