From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Smart Subject: Re: [PATCH] FC Transport support for vports based on NPIV Date: Mon, 14 May 2007 11:57:50 -0400 Message-ID: <464886FE.7060001@emulex.com> References: <1176408091.19824.20.camel@localhost.localdomain> <20070514121239.GA23620@schmichrtp> <464886B6.8050509@emulex.com> Reply-To: James.Smart@Emulex.Com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from emulex.emulex.com ([138.239.112.1]:62767 "EHLO emulex.emulex.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753388AbXENP6A (ORCPT ); Mon, 14 May 2007 11:58:00 -0400 In-Reply-To: <464886B6.8050509@emulex.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James.Smart@Emulex.Com Cc: Christof Schmitt , linux-scsi@vger.kernel.org, duane.grigsby@qlogic.com reposting w/ the title James Smart wrote: > > Christof Schmitt wrote: >> James, >> >> i try to understand what the introduction of the vports means for >> zfcp, since >> this driver also supports NPIV. The documentation for the fc transport >> class >> describes a driver that would fully control the adapter and the >> creation of >> virtual address. Since you mentioned Xen, i assume that this could be >> a dom0. > > All true. But, there is the notion that there is a driver that thinks it's > controlling the adapter, but it's actually talking to a virtual thing, that > traps the driver's FLOGI's and turns it into FDISCs... > >> With zfcp, the hardware FCP adapter does NPIV and only hands out the >> virtual >> address to individual Linux instances. zfcp gets the assigned virtual >> address >> for the Linux instance. This address is used for allocating the scsi_host >> structure. Basically, the whole system uses NPIV, but each Linux only >> uses one >> assigned virtual WWPN. > > Yes - I understand. For all intents and purposes, that virtual address is > treated as an adapter. > >> My current understanding is that the vports introduced in the fc >> transport >> class do not affect the Linux systems that only use one virtual >> address. To >> map this to Xen, the dom0 would use the vports to show all virtual >> address, and >> each domU would use the assigned virtual address without showing the >> vport in >> sysfs. Is this correct? >> >> Christof > > Agreed. It should mean nothing to the zfcp driver. Nothing changes in > the driver > if it will always be a single address. > > Although - if your hardware-to-driver interface had the ability to > instantiate > a new address, you could augment your driver to support the vport calls. > That's > a choice for you though. > > -- james > > PS: One thing I didn't call out in the vport patches was the expectation > that > the vport-supporting driver had to set the PPN attribute appropriately. > And... did you see that T11 is trying to change what the PPN is set to > - the > fabric port_name not the physical N_Port port_name. >