Re: Hot plug scripts not working c/s 19355

[Jeremy Fitzhardinge <jeremy@goop.org>]

Dan Magenheimer wrote:
> A heads-up that I just got a "(tap)...Hotplug scripts not working"
> completely unrelated to pvops.
>
> I updated hypervisor and tools (but notably NOT dom0 kernel) to
> xen-unstable c/s 19355.  Launching a domain now fails with the
> above error.  Rolling tools (only) back to 19187 makes the
> problem go away.
>   

Any chance you could try to pinpoint the failing version?

> Is there maybe a new dependency between tools and dom0 kernel?
>   

There's certainly nothing explicit.  Bisecting the kernel seemed to 
point to some cleanups I did around /dev/privcmd, but that's not really 
used for hotplug/xenbus stuff (I mean, it is at a low level, but surely 
xenbus would break entirely if it were broken).  And those changes work 
with older tools.  (And the bisection was probably lead astray by the 
other hotplug bug.)

Maybe some timing/ordering thing?  Unfortunately I know very little 
about how things are supposed to work at that level.  IanC said that he 
thought that xenbus watches were failing to fire, which makes me wonder 
if Gerd's xenstore fixes might be worth looking at more closely.

    J