Hello, while working on a demonstrator for a green-IT project, to show scheduled machine shutdown and powering depending on various conditions, I wondered if I could use QEMU with wake-on-lan transparently, but it seems it's not implemented at all.
I though I could try to add support for it, and with -S it theorically should be doable at least for the first boot, but the network packets do not go much further until the NIC is actually initialized, as most network layers use qemu_can_send_packet() which returns 0 if the machine is stopped. Hacking this function to return 1 seems to push the packet upward, but I couldn't find a single point where I could check for WOL packets, different -net subsystems using different code paths. Also, it seems -no-shutdown doesn't actually "stop the emulation" as said in the manual, it actually keeps the vm running (and using cpu), despite the OS trying to shutdown via ACPI. At least I tested so with Haiku (and acpi=true in kernel config), which properly exits QEMU without -no-shutdown. Ideally this would evolve into supporting IPMI, which would allow managing VMs exactly like physical servers without concern, appart launching the actual process first. cf. http://en.wikipedia.org/wiki/Intelligent_Platform_Management_Interface http://openipmi.sourceforge.net/ Anyone interested in this ? Anyone tried already ? François.