From mboxrd@z Thu Jan 1 00:00:00 1970 From: Knut Omang Subject: Re: [PATCH 9/9] ib_verbs: Add a new qp create flag to request features for Ethernet over IB Date: Wed, 07 Sep 2016 19:33:25 +0200 Message-ID: <1473269605.26625.152.camel@oracle.com> References: <1472774969-18997-1-git-send-email-knut.omang@oracle.com> <1472774969-18997-10-git-send-email-knut.omang@oracle.com> <20160902021729.GE30057@obsidianresearch.com> <1472792670.9410.276.camel@oracle.com> <1472814057.3975.47.camel@oracle.com> <20160902163451.GC24997@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160902163451.GC24997-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jason Gunthorpe Cc: Doug Ledford , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On Fri, 2016-09-02 at 10:34 -0600, Jason Gunthorpe wrote: > On Fri, Sep 02, 2016 at 01:00:57PM +0200, Knut Omang wrote: > > On Fri, 2016-09-02 at 07:04 +0200, Knut Omang wrote: > > > On Thu, 2016-09-01 at 20:17 -0600, Jason Gunthorpe wrote: > > > > > > > > On Fri, Sep 02, 2016 at 02:09:29AM +0200, Knut Omang wrote: > > > > > > > > > > Some Infiniband HCAs need to know if a QP is going to > > > > > be used for Ethernet over IB (EOIB). > > > > You will have to send this after your driver. I recommend a patch > > > > proposing this functionality with your driver as the example > > > > implementation, along with a kernel user, as mellanox typically does. > > > It's a bit of a chicken and egg situation since the driver > > > depends on the patches. If I can 'tick off' this bit soon, I can move ahead and > > > get to the send the driver too. > > > > > > There's not much info in the driver - it just forwards that bit to a hardware bit > > > and it all happens from there. But hardware needs to know when to set that bit, > > > as it is only valid when operating as transport for Ethernet. > > > > > > Please - it would be a big help for me (saving a lot of work down the line that > > > is better spent working with the community than with handling more version issues later) > > > if I can get an indication that just that bit would be acceptable 8-D ... > > > > I will add the following further justification to the commit message for v2: > > > > Support for encapsulation of Ethernet over IB (EoIB) is a generic feature > > where different HCA implementations can include different special features. > > One example is that if the HCA knows the QP is going to be used for Ethernet, > > the implementation can ensure that all messages sent on this QP represents > > a properly formatted encapsulation of Ethernet frames with legal header values. > > Or the HCA can perform the encapsulation itself. > > It would be better to remove support for this from your driver in the > initial submission. Ok, will do. > Keep new uAPIs in new driver submissions to an absolute minimum please. I completely agree with you that APIs need a lot of care and consideration, rest assure ;-) > And as I said, you need to introduce a kernel user of this bit as > well, so the driver alone is not enough. Ok. The Ethernet driver using this is outside of my control. Knut > > Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html