Re: [Qemu-devel] [PATCH 0/4] Machine config files

[Gerd Hoffmann]

On 06/12/09 15:37, Markus Armbruster wrote:
> It can be compiled from source with dtc, which doesn't seem to be
> included in the patch series.  The language accepted by dtc is pretty
> low-level: it talks NUL-terminates strings, byte strings and arrays of
> "cells" (32 bit integers).

[ a bunch of examples snipped ]

> Is that really what we want for a configuration file?

I do see a point in using fdt as qemu-internal representation.  ppc 
needs it anyway.  It is also a nice way to store the guest configuration 
for save/load and migration, you can just send the blob over the wire. 
And we can hide the details such as cells behind some nifty helper 
functions.

Qemu users should not be required to be fdt experts though.  We need 
another, more user-friendly interface to configure virtual machines.

libfdt has functions to modify the device tree.  I think we will need 
them to keep the fdt in sync with the machine configuration when 
hot-plugging in and out devices (otherwise the fdt is useless for 
migration).  So when we have code to handle the fdt updates triggered by 
the "drive_add ..." monitor command anyway, also handling the -drive 
command line switch (or the same input from a more userfriendly machine 
config file) should be easy.

cheers,
  Gerd