Re: [Qemu-devel] [PATCH v2] pc: allow raising low memory via max-ram-below-4g option

[Gerd Hoffmann]

  Hi,

> > > I wonder whether we should just bite the bullet and ask management to
> > > maintain the physical memory map for us, instead of trying to give us
> > > hints.
> > 
> > I doubt this simplified things, given the backward compatibility
> > constrains we have.
> > 
> > cheers,
> >   Gerd
> 
> That's exactly what would become simple.
> For backwards compatibility we would leave things alone
> if the new flags for the memory map aren't specified.

But we'll add a bunch of new code for the new config mode which allows
management to maintain the physical memory map.  And we'll expect
management know about a bunch of machine type internals.  That isn't a
simplification.

> This would allow people to e.g. allocate phy address
> ranges for things like nvdimm which has been
> problematic in the past.

Didn't follow nvdimm discussions.  If you think we really need that
anyway to solve certain issues, sure, go ahead and I happily adjust this
patch to use the new infrastructure.

cheers,
  Gerd