Re: [Qemu-devel] [PATCH 21/27] pc: add memory hotplug 440fx machine

[Michael S. Tsirkin]

On Thu, Nov 21, 2013 at 05:09:27PM +0100, Andreas Färber wrote:
> Am 21.11.2013 15:34, schrieb Igor Mammedov:
> > On Thu, 21 Nov 2013 15:13:12 +0100
> > Andreas Färber <address@hidden> wrote:
> >> Am 21.11.2013 06:48, schrieb Li Guang:
> >>> Why not give the memory that not be hot-added a chance to be placed on
> >>> one memory slot?
> >>
> >> Seconded, I believe I requested that on the previous version already.
> > Because current initial memory allocation is a mess and this already
> > large series would become even more large and intrusive, so far series
> > it relatively not intrusive and self contained.
> > 
> > I believe re-factoring of initial memory to use Dimm devices should be
> > done later on top of infrastructure this series provides.
> 
> My problem with that is that that would be a semantically incompatible
> modeling change.

Yes but we are not merging this for 1.7, time enough to make
changes before 1.8.

> With your series we might have /machine/dimm.0/child[0]
> be the first hot-plugged memory and once such a refactoring is done,
> child[0] silently becomes -m and child[1] is the hot-added one.
> 
> So if we know that we want/need to change the infrastructure, why not
> add a single patch (?) to allocate one additional object on the bus now?
> Unless we actually write the code, we won't know whether there are some
> incorrect hot-plug assumptions in the dimm code.
> 
> Andreas
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