Re: [PATCH v2 08/10] nvme-pci: Add support for P2P memory in requests

From: Bart Van Assche
Date: Fri Mar 09 2018 - 00:08:51 EST


On Thu, 2018-03-01 at 15:58 +0000, Stephen Bates wrote:
> > Any plans adding the capability to nvme-rdma? Should be
> > straight-forward... In theory, the use-case would be rdma backend
> > fabric behind. Shouldn't be hard to test either...
>
> Nice idea Sagi. Yes we have been starting to look at that. Though again we
> would probably want to impose the "attached to the same PCIe switch" rule
> which might be less common to satisfy in initiator systems.
>
> Down the road I would also like to discuss the best way to use this P2P
> framework to facilitate copies between NVMe namespaces (on both PCIe and
> fabric attached namespaces) without having to expose the CMB up to user
> space. Wasn't something like that done in the SCSI world at some point
> Martin?

Are you perhaps referring to the following patch series: "Copy Offload"
(https://www.spinics.net/lists/linux-scsi/msg74680.html /
https://lwn.net/Articles/592094/)? I will contact Martin off-list and in
case he wouldn't have the time myself to revive that patch series then I
will free up some time to work on this.

Bart.