Re: [PATCH] Paravirt framebuffer frontend kernel support [1/5]

[Ewan Mellor <ewan@xensource.com>]

On Thu, Nov 02, 2006 at 04:19:55PM +0000, Steven Smith wrote:

> > Okay, thanks.  Next stupid question: I'm looking for a *user space*
> > xenbus_register_backend().  Where is it?
> I don't think there is such a thing at the moment, just because we
> don't currently have any userspace backends.
> 
> I think in your particularly case, the easiest thing is probably going
> to be to get xend to set up a skeleton xenstore area for the frontend
> in the usual way (see DevController.py and e.g. netif.py).  With a
> normal in-kernel driver you'd be able to watch the relevant location
> to notice when a new device is created, but you don't have a
> permanently-running daemon, which makes that a bit tricky.  I think
> it'd be okay to just fake the relevant entry in the store (set
> ${backend_path}/hotplug-status to connected) from the backend.  It's a
> little skanky, but it should be adequate and reasonably
> straightforward to implement.

This is what we do for blktap -- tools/examples/blktap just calls success
immediately, which writes "connected" into the store as you suggest.

Ewan.