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Date:   Tue, 30 Jun 2020 15:36:09 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Maximilian Heyne <mheyne@amazon.de>
Cc:     Amit Shah <aams@amazon.de>, stable@vger.kernel.org,
        Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@fb.com>,
        Christoph Hellwig <hch@lst.de>,
        Sagi Grimberg <sagi@grimberg.me>,
        linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] nvme: validate cntlid's only for nvme >= 1.1.0
Message-ID: <20200630133609.GA20809@lst.de>
References: <20200630122923.70282-1-mheyne@amazon.de> <20200630133358.GA20602@lst.de>
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On Tue, Jun 30, 2020 at 03:33:58PM +0200, Christoph Hellwig wrote:
> On Tue, Jun 30, 2020 at 12:29:23PM +0000, Maximilian Heyne wrote:
> > Controller ID's (cntlid) for NVMe devices were introduced in version
> > 1.1.0 of the specification. Controllers that follow the older 1.0.0 spec
> > don't set this field so it doesn't make sense to validate it. On the
> > contrary, when using SR-IOV this check breaks VFs as they are all part
> > of the same NVMe subsystem.
> > 
> > Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
> > Cc: <stable@vger.kernel.org> # 5.4+
> 
> The first hunk looks ok, the second doesn't make sense as fabrics
> was only added with NVMe 1.2.2.  I can fix it up when applying if you
> are ok with that.
> 
> But you guys really shouldn't be doing SR-IOV with 1.0 controllers
> independent of this..

And actually - 1.0 did not have the concept of a subsystem.  So having
a duplicate serial number for a 1.0 controller actually is a pretty
nasty bug.  Can you point me to this broken controller?  Do you think
the OEM could fix it up to report a proper version number and controller
ID?