[Qemu-devel] First shot at adding IPMI to qemu

[minyard]

I had asked about getting an IPMI device into qemu and received some
interest, and it's useful to me, so I've done some work to add it.
The following patch set has a set of patches to add an IPMI KCS
device, and IPMI BT device, a built-in BMC (IPMI management controller),
and a way to attach an external BMC through a chardev.

There was some discussion on whether to make the BMC internal or
external, but I went ahead and added both.  The internal one is
fairly basic and not extensible, at least without adding code.
I've modified the OpenIPMI library simulator to work with the
external interface to allow it to receive connections from the
qemu external simulator with a fairly basic protocol.

I've also added the ability for the OpenIPMI library to manage
a VM to power it on, power it off, reset it, and handle an IPMI
watchdog timer.  So it looks quite like a real system.  Instructions
for using it are in the OpenIPMI release candidate I uploaded to
https://sourceforge.net/projects/openipmi

Since IPMI can advertise its presence via SMBIOS, I added a
way for a driver to add an SMBIOS entry.  I also added a way
to query a free interrupt from the ISA bus, since the interrupt
is in the SMBIOS entry and nobody really cares which one is used.