Re: [PATCH] nvme: validate cntlid's only for nvme >= 1.1.0

[Maximilian Heyne <mheyne@amazon.de>]

On 6/30/20 3:36 PM, Christoph Hellwig wrote:
> 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.

I'd be totally ok with that.

>>
>> But you guys really shouldn't be doing SR-IOV with 1.0 controllers
>> independent of this..

So far it worked...

> 
> 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?
> 

I meant that the VF NVMe controllers will all land in the same subsystem from
the kernel's point of view, because, as you said, there was no idea of different
subsystems in the 1.0 spec.
It's an older in-house controller. Seems to set the same serial number for all
VF's. Should the firmware set unique serials for the VF's instead?

Thanks
Max



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