From mboxrd@z Thu Jan 1 00:00:00 1970 From: Santosh Shilimkar Subject: Re: [PATCH 9/9] ib_verbs: Add a new qp create flag to request features for Ethernet over IB Date: Fri, 2 Sep 2016 09:19:43 -0700 Message-ID: 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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1472814057.3975.47.camel-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Knut Omang , Jason Gunthorpe Cc: Doug Ledford , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 9/2/2016 4:00 AM, 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. >> Right. It comes down to removing mask filter at verbs layer and letting driver get the full view of it so that it can better deal with it based on information. >> 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. > Don't want to hijack your patch but I also have seen another need where ULP needs to pass additional information to driver for creating RC qp with couple of add-ons . My current thought is to use reserved QP flag bits (bits 26-31, for low level drivers' internal use) but wanted to check if there is any objection to it. Regards, Santosh -- 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