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Date: Tue, 8 Aug 2017 00:04:49 -0400
From: Keith Busch <keith.busch@intel.com>
To: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>,
        Christoph Hellwig <hch@infradead.org>, Hannes Reinecke <hare@suse.de>,
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        Suganath Prabu Subramani 
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        linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
        martin.petersen@oracle.com
Subject: Re: [PATCH v2 00/13] mpt3sas driver NVMe support:
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On Mon, Aug 07, 2017 at 08:45:25AM -0700, James Bottomley wrote:
> On Mon, 2017-08-07 at 20:01 +0530, Kashyap Desai wrote:
> > 
> > We have to attempt this use case and see how it behaves. I have not
> > tried this, so not sure if things are really bad or just some tuning
> > may be helpful. I will revert back to you on this.
> > 
> > I understood request as -??We need some udev rules to be working well
> > for *same* NVME drives if it is behind <mpt3sas> or native <nvme>.
> > Example - If user has OS installed on NVME drive which is behind
> > <mpt3sas> driver as SCSI disk should be able to boot if he/she hooked
> > same NVME drive which is detected by native <nvme> driver (and vice
> > versa.)
> 
> It's not just the udev rules, it's the tools as well; possibly things
> like that nvme-cli toolkit Intel is doing.

It looks like they can make existing nvme tooling work with little
effort if they have the driver implement NVME_IOCTL_ADMIN_COMMAND, and
then have their driver build the MPI NVMe Encapsulated Request from that.