Re: New domain builder in xen-unstable

[Gerd Hoffmann <kraxel@suse.de>]

Keir Fraser wrote:
> On 26/1/07 5:04 pm, "Hollis Blanchard" <hollisb@us.ibm.com> wrote:
> 
>>> Not sure what you mean by "our own domain builder"; we've been
>>> implementing xc_linux_build() for quite a while now (and thus integrated
>>> with xend).
>> Sorry, I misunderstood. I was seeing all the libelf churn, and I missed
>> the fact that xc_linux_build() is going away entirely (?).
>>
>> I'm still not sure what you mean by "our own domain builder" -- there is
>> simply no way we're going to add more ifdefs to
>> tools/libxc/xc_linux_build.c (or equivalent)...
> 
> xc_linux_build() is still provided in the 'new world' and is still used by
> xend. For ia64/x86 it is now a thin wrapper around Gerd's new
> domain-building infrastructure. For ppc you can continue to have your very
> own version under libxc/powerpc if you want to, and not use Gerd's new
> domain-building infrastructure. But the elf code that you rely on is going
> away, so you need to move to using libelf, which I'm sure Gerd can give you
> some pointers about.

libelf is used both within the xen kernel (dom0 builder) and the tools.

Have a look at changeset 13618, this does the dom0 builder port for x86
and ia64 (build-tested only), something simliar is needed for the ppc
dom0 builder.

For the tools:  You can either switch over the existing ppc builder in
libxc/powerpc/ to use libelf, which likely is simliar to the dom0
builder conversion to libelf.

The other option is to use the new builder code in libxc/xc_dom_*.c.
Some code is already there.  The ia64 bits should at least compile, with
luck even work out-of-the-box.  The ppc bits I didn't even compile.  The
places with architecture-specific code are:

xc_dom_{ia64,powerpc}.c
	setup arch-specific structs (start_info, vcpu_context).

xc_dom_boot.c
	invoke the hypercalls needed to boot the domain.  There are two
	functions for architecture-specific code, ppc must hook in the
	devtree setup there (if you decide to use the new builder).

The domain builder core code should need no changes in theory ;)

Feel free to ask if there are any questions.

HTH & cheers,
  Gerd

-- 
Gerd Hoffmann <kraxel@suse.de>