Re: [PATCH v2 3/3] nvme: prevent ioq creation for discovery controllers

[Hannes Reinecke]

On 7/2/25 02:58, Kamaljit Singh wrote:
> Prevent ioq creation for discovery-controllers as the spec prohibits
> them, similarly to the administrative controllers.
>
> Reference: NVMe Base rev 2.2, sec 3.1.3.4, fig 28.
While this might be true, we already deal with discovery controllers
just fine, and never had issues with I/O queues being created.
Presumably because discovery controllers never exposed I/O queues
in the first place.

Which also means that admin controllers should work already if they
would not expose I/O queues.

We _might_ reduce the number of queues to '1' in nvme_set_queue_count(),
but then we should issue a warning here as this would be a configuration
error on the target side.

'Prohibited' cuts both ways; the host shouldn't ask for it and the
controller shouldn't advertise it...

Or that's at least my reading. Might be worthwhile clarifying this
at FMDS.

Cheers,

Hannes
--
Dr. Hannes Reinecke                  Kernel Storage Architect
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