Re: [PATCH for-rc] IB/cma: Fix false P_Key mismatch messages

[Jason Gunthorpe <jgg@nvidia.com>]

On Wed, May 05, 2021 at 02:54:01PM +0200, Håkon Bugge wrote:
> There are three conditions that must be fulfilled in order to consider
> a partition match. Those are:
> 
>       1. Both P_Keys must valid
>       2. At least one must be a full member
>       3. The partitions (lower 15 bits) must match
> 
> In system employing both limited and full membership ports, we see
> these false warning messages:
> 
> RDMA CMA: got different BTH P_Key (0x2a00) and primary path P_Key (0xaa00)
> RDMA CMA: in the future this may cause the request to be dropped
> 
> even though the partition is the same.
> 
> See IBTA 10.9.1.2 Special P_Keys and 10.9.3 Partition Key Matching for
> a reference.
> 
> Fixes: 84424a7fc793 ("IB/cma: Print warning on different inner and header P_Keys")
> Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
> ---
>  drivers/infiniband/core/cma.c | 22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)

What is this trying to fix?

IMHO it is a bug on the sender side to send GMPs to use a pkey that
doesn't exactly match the data path pkey.

Jason