Re: [Qemu-devel] [PATCH 1/2] pc-dimm: No numa option shouldn't break hotplug memory feature

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 17 Sep 2014 16:32:20 +0800
Hu Tao <hutao@cn.fujitsu.com> wrote:

> On Tue, Sep 16, 2014 at 06:39:15PM +0800, zhanghailiang wrote:
> > If we do not configure numa option, memory hotplug should work as well.
> > It should not depend on numa option.
> > 
> > Steps to reproduce:
> > (1) Start VM: qemu-kvm -m 1024,slots=4,maxmem=8G
> > (2) Hotplug memory
> > It will fail and reports:
> > "'DIMM property node has value 0' which exceeds the number of numa nodes: 0"
> > 
> 
> I rememberd Tang Chen had a patch for this bug, this is what Andrey suggested:
> 
>   I thnk that there should be no
>   cases when dimm is plugged (and check from patch is fired up) without
>   actually populated NUMA, because not every OS will workaround this by
>   faking the node.
This doesn't take in to account that dimm device by itself has nothing to do
with numa (numa is just optional property of its representation in ACPI land
and nothing else).

In case initial memory is converted to dimm devices, qemu can be
started without numa option and it still must work.

So I'm in favor of this path.

>
> https://lists.nongnu.org/archive/html/qemu-devel/2014-08/msg04587.html
> 
> Have you tested this patch with Windows guest?
> 
> Regards,
> Hu