Re: [PATCH RFC] nvme-ioctl: propagate PRP1 from ioctl to admin cmd

[David Epping <david.epping@missinglinkelectronics.com>]

On Wed, Jun 24, 2026 at 09:40:45AM +0200, Christoph Hellwig wrote:
> On Tue, Jun 23, 2026 at 06:19:08AM -0600, Keith Busch wrote:
> > Partitioning device resources to assign to special purposes should be
> > under a well defined framework. Unfortunately the only thing I know of
> > approaching this is SIOV. :) Not sure how other maintainers and
> > developers feel about it, but that's the route I would go for this. It
> > at least provides memory access on a queue granularity and neatly
> > separates the control plane.
> 
> Yeah, we can't just hand out queues.  I/O to all namespaces can be done
> on queue, and any queue can address any IOVA, so this is fundamentally
> unsafe.  Add to that fun like abort handling and it's just not going
> to work at all.  We had at least to previous public attempts at such
> schemes (Damiens' libvnme back in the day, and the Mellanox nvmet
> offloading) that were rejected for the same reason.
> 

Thank you both for your feedback, I get the point. I'll definitely look
into using SRIOV or SPDK to migrate the system to an unmodified upstream
NVMe driver mid-term.
Thank you for such a stable base to build upon, David