[Libvir] Flag to virDomainReboot to immediately reboot a domain?

Hi, For fencing Xen domains, I would like the ability to guarantee an immediate reboot of a domain without notifying the OS inside. Basically, I would like something equivalent to pressing the reset button on a physical machine. There's a currently unused "flags" option to virDomainReboot which would allow such an addition without breaking the ABI. Doing getXMLDesc/Destroy/Create introduces a race condition in clusters: What if outside management software notices notices the VM is missing and decides to start it up on *another* host node before we bring up the VM again using the Create call? An immediate reboot should eliminate the race (even though it's a very small window), and probably will not add any complexity. For now, 'reboot' is done as above, and 'off' is a simple Destroy call. 'On' is not possible to implement for various reasons, the most obvious of which is that the caller does not know any of the configuration information about particular domUs (except for their names). -- Lon