Re: [Qemu-devel] [PATCH 2/5] exec: qemu_ram_alloc_device, qemu_ram_resize

[Dr. David Alan Gilbert]

* Paolo Bonzini (address@hidden) wrote:
> 
> 
> On 19/11/2014 15:13, Dr. David Alan Gilbert wrote:
> > Since we've wondered off the actual ACPI table stuff into general
> > ROM sizing, I'd like to propose some concrete fixes:
> > 
> >   1) We explicitly name the bios file in a .romfile attribute for
> >      all ROMs.
> >   2) The code that uses .romfile has an expansion for $MACHINETYPE
> >   3) We actually symlink all of those together, anyone who wants/has
> >      to deal with different versions can downstream.
> >   4) The machine types contain size attributes for the ROMs that
> >      are generoously larger than the ROMs anyone currently uses.
> > 
> > I think 1..3 should deal with those of us who have to deal with different
> > ROM versions on different machine types.
> 
> It should, but it's a solution in search of a problem.

Well we already do something close to 1 & 2 downstream but more ad-hoc;
it's just a generalisation (and 4 from padding the size of our images).
So we already had that problem.

> 
> > 4 might be good enough for the ACPI tables if you can bound it.
> 
> Already doing that (rounding to 128k, warning if >64k), but it is not a
> definitive solution.
> 
> We also do (4) for ROMs, since VGA BIOSes use only 36k out of 64k and
> iPXE ROMs use only ~200k out of 256k.
> 
> Paolo
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK