Re: [PATCH 0/8] Virtio-over-PCIe on non-MIC

From: Arnd Bergmann
Date: Thu Jan 17 2019 - 10:32:02 EST

On Thu, Jan 17, 2019 at 4:19 PM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> On Thu, Jan 17, 2019 at 07:15:29AM -0800, Christoph Hellwig wrote:
> > On Thu, Jan 17, 2019 at 01:39:27PM +0100, Arnd Bergmann wrote:
> > > Can you describe how you expect a VOP device over NTB or
> > > PCIe-endpoint would get created, configured and used?
> > > Is there always one master side that is responsible for creating
> > > virtio devices on it, with the slave side automatically attaching to
> > > them, or can either side create virtio devices? Is there any limit on
> > > the number of virtio devices or queues within a VOP device?
> >
> > For VOP device over NTB your configure your device using configfs
> > on one side, and for the other side it will just show up like any
> > other PCIe device, because it is.
> Sorry, I mean over the PCI-EP infratructure of course. NTB actually
> is rather hairy and complicated.

My understanding was that with virtio, we would be able to have multiple
virtio devices on a single PCI-EP port, so you need a multi-step
configuration: You first set up the PCI-EP to instantiate a VOP device,
which is then seen on both ends of the connection. The question
is how to create a particular virtio device instance (or a set of those)
inside of it.