[ofa-general] [PATCH] libmlx4: Fix the value of the pkey_index in the completion

[Hal Rosenstock]

On Mon, 2008-01-07 at 14:49 +0200, Dotan Barak wrote:
> Dotan Barak wrote:
> > Yevgeny Kliteynik wrote:
> >> Dotan Barak wrote:
> >>> Or Gerlitz wrote:
> >>>> Dotan Barak wrote:
> >>>>> Fix the value of the pkey_index in the completion to get a valid 
> >>>>> value for GSI QPs.
> >>>>
> >>>> Is libmthca fine in that respect?
> >>> As much as i know, everything is fine with mthca/libmthca.
> >>>
> >>> We saw several problems only in ConnectX (because of the new low 
> >>> level driver).
> >>>
> >>> Right now, we are doing some more checks to check the mlx4_0 low 
> >>> level driver as well as the IB core.
> >>> After that we'll check the mthca low level driver too.
> >>
> >> Currently OpenSM doesn't support any non-default pkey
> >> (or any pkey at index other than 0) in sa queries.
> >> When a request is received, opensm doesn't extract the
> >> right pkey from the mad header - it replaces it with a
> >> default pkey, and when a response is sent, OpenSM always
> >> uses pkey at index 0.
> >>
> >> -- Yevgeny
> > FYI: after several testings it seems that mthca low level driver don't 
> > have this problem.
> >
> > Dotan
> >
> 
> Just to make sure that everything is clear: I checked that the mthca low 
> level driver can extract
> the right pkey_index in the completion of GSI QP.
> 
> The problem that Yevgeny mentioned exists in the openSM and i opened a 
> bug on this issue.

Some comments on the issues raised above:

1. There has already been discussion on this list of other OpenFabrics
components assuming the default PKey at index 0 (and yes, this is not
mandated by IBA).

2. As to the impact of using a non default PKey (in the BTH) for
querying SA, is this really used in any implementations ? It makes
deployment of SM difficult (needing much more configuration). That's not
to say this isn't a bug but more speaks to the severity of it. IMO it
should be documented as a current limitation.

[Also, note that user MAD API only supports pkey index at recent kernel
and library versions.]

-- Hal

> Dotan