Re: [patch 5/6] frontend device shutdown

[Gerd Hoffmann <kraxel@suse.de>]

  Hi,

> I don't want to add new XenbusStates. I'm talking about a different,
> hotplug, status that is rather different: it indicates the status of the
> device from the p.o.v. Of the admin and control tools (basically, 'online'
> or 'offline').

I understand that, this is a related but different issue though.

> Two options:
>  1. Always enter Closed state, and then run a cleanup phase in the kexec
> code which iterates over xenstore device directories, switching
> Closed->Initialising.
>  2. Enter state Initialising if backend's 'hotplug_status' node indicates
> 'online'. Gate xenbus_probe_node() on kernel_status <= STATE_RUNNING (the
> shutdown code only ever gets run after kernel_status is bumped to one of the
> shutdown states, I believe).
> 
> I think (1) is architecturally cleaner, but I understand it may be a pain to
> implement in the constrained post-shutdown kexec environment. I don't think
> (2) is too bad, and is more along the lines of what you have already.

I'll try (1).  I don't expect it being that hard, I expect doing that in
the old kernel _after_ unregistering the watches should work just fine.

cheers,

  Gerd

-- 
Gerd Hoffmann <kraxel@suse.de>
http://www.suse.de/~kraxel/julika-dora.jpeg