> From: Jason Gunthorpe <jgg@xxxxxxxxxxxx> > Sent: Thursday, February 27, 2020 3:55 PM > > ---------------------------------------------------------------------- > On Thu, Feb 27, 2020 at 01:11:13PM +0000, Michal Kalderon wrote: > > Hi Kamal, Jason, > > > > Running a version of ibv_devinfo compiled against an old rdma-core > > (ibv_devinfo from libibverbs-utils-16.2-3-fc28.x86_64 ) failed to run with > rdma-core release 28.0 for qedr. > > > > The patch that caused this is commit c2841076 > > https://urldefense.proofpoint.com/v2/url?u=https- > 3A__github.com_linux- > > 2Drdma_rdma- > 2Dcore_commit_c28410765bdfe5cbed3cb2cdb1584eac3941469c-23d > > iff- > 2D8da8bc8b2790169de557d5dee83a278e&d=DwIBAg&c=nKjWec2b6R0mOyP > az7xt > > fQ&r=5_8rRZTDuAS-6X-cGRU9Fo4yjCnkS1t7T3- > gjL4FQng&m=8roKblaWiyWNhzEkhi8 > > gJYJs1ZHqJ0lqf_0OMh3fHBM&s=x5- > fhg21NUEcxJ2zxM135ujpopHtey138zz9waiflS8 > > &e= > > c28410765bdf > > > > libibverbs: Fix incorrect return code ... > > > > The proper return code is EOPNOTSUPP when an operation is not > supported. > > > > Signed-off-by: Kamal Heib <kamalheib1@xxxxxxxxx> > > > > The reason it failed is because qedr doesn't have a query_device_ex > > callback, so vctx->query_device_ex returns EOPNOTSUPP, and old > > libibverbs Compares the return code to ENOSYS > > This is surprising and unfortunate > > > I think applications compiled against old rdma-core should continue to > > run on new ones as well. Can this commit be reverted? > > I would prefer to only revert the little bit that might be needed for > compatability. > > Perhaps we should change the dummy function to implement > query_device_ex for all providers? Zeroing the extended data should be > sufficient I think. I've submitted pull-request #713 that implements the dummy function. Thanks, Michal > > Unfortunately we are changing return codes inadvertantly quite often, and > the providers tend to use different codes. > > Jason
