Re: udev PATH_ID for virtio devices

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Mar 27, 2014 at 07:43:34PM +0100, Kay Sievers wrote:
> On Thu, Mar 27, 2014 at 6:30 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> 
> > If the virtio device is a PCI device, it is really best to
> > treat it like you treat any other PCI function (I guess you mean
> > function and not device, right? We support multifunction
> > devices and some people do pack multiple NICs in a single device)..
> >
> > At the moment many devices in a single pci function can not happen on a
> > PCI system (no multiport) but if we add multiport, we'll follow some
> > existing standard to expose this information to the guest.
> 
> This means, that there can currently never multiple devices below one
> and the same virtio parent device?
> 
> Kay

There's a single virtio device per pci function (you keep saying
device but I hope the distinction is clear and this is
just slip of the tongue).

For net devices under a pci function that is also currently the case,
but I can't yet tell you for sure ahead of the time how we'll present
multiport devices if we ever implement them.

I'm guessing there will be multiple net devices under
a single pci device and we'll present a sysfs attribute with the port
number in this case.

Hmm maybe we should go ahead and add a place-holder
attribute so that it's future-proof?

I'll write a patch like that and we'll see how it's accepted.

-- 
MST