Re: [Qemu-ppc] [SLOF] [PATCH v4] board-qemu: add private hcall to inform host on "phandle" update

[David Gibson]

On Wed, Sep 13, 2017 at 06:21:52PM -0500, Segher Boessenkool wrote:
> On Sat, Sep 09, 2017 at 01:38:29PM +1000, David Gibson wrote:
> > [Aside: strictly, it's not an FDT piece that goes to the guest OS;
> > the guest performs a sequence of calls to traverse the DT fragment.
> > qemu uses an fdt fragment as an internal detail, but that's not part
> > of the protocol]
> 
> Ah that is good to hear :-)

It's really not.  Spitting in a chunk of FDT would be a simpler and
more efficient method of accomplishing the same thing as the horrid
set of PAPR mandated RTAS calls (these are *not* the same as the
regular OF calls used at boot time - the boot time OF client interface
is long gone).  But then, I guess FDT wasn't a thing when that bit of
the PAPR spec was made.

> By the time qemu is queried for this information it should already know
> the real phandle of the interrupt controller;

Nope.  How would it?  After it fires it off, qemu is no longer in
communication with SLOF.

> can't it just patch it in?
> 
> 
> Segher
> 

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

signature.asc
Description: PGP signature