[RFC PATCH 0/2] virtio nvme

[Nicholas A. Bellinger]

On Thu, 2015-09-17 at 11:18 -0700, Ming Lin wrote:
> On Wed, Sep 16, 2015 at 11:10 PM, Nicholas A. Bellinger
> <nab at linux-iscsi.org> wrote:
> > Hi Ming & Co,
> >> >
> >> > At first glance it seems like the virtio_nvme guest driver is just
> >> > another block driver like virtio_blk, so I'm not clear why a
> >> > virtio-nvme device makes sense.
> >>
> >> I think the future "LIO NVMe target" only speaks NVMe protocol.
> >>
> >> Nick(CCed), could you correct me if I'm wrong?
> >>
> >> For SCSI stack, we have:
> >> virtio-scsi(guest)
> >> tcm_vhost(or vhost_scsi, host)
> >> LIO-scsi-target
> >>
> >> For NVMe stack, we'll have similar components:
> >> virtio-nvme(guest)
> >> vhost_nvme(host)
> >> LIO-NVMe-target
> >>
> >
> > I think it's more interesting to consider a 'vhost style' driver that
> > can be used with unmodified nvme host OS drivers.
> >
> > Dr. Hannes (CC'ed) had done something like this for megasas a few years
> > back using specialized QEMU emulation + eventfd based LIO fabric driver,
> > and got it working with Linux + MSFT guests.
> 
> Are the patches already in qemu upstream and LIO upstream?
> 
> I found you played it in 2010. Is it?
> [QEMU-KVM]: Megasas + TCM_Loop + SG_IO into Windows XP guests
> https://groups.google.com/forum/#!topic/linux-iscsi-target-dev/3hdaI6H3X0A
> 

AFAIK it was never submitted for kernel/QEMU upstream inclusion.

Dr Hannes, would you be so kind to put this code in a public repo to
grok as an example for nvme host-aware emulation..?

--nab