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

[Igor Mammedov <imammedo@redhat.com>]

On Tue, 23 Sep 2014 18:07:16 +0800
zhanghailiang <zhang.zhanghailiang@huawei.com> wrote:

> On 2014/9/23 17:01, Igor Mammedov wrote:
> > On Mon, 22 Sep 2014 14:17:28 +0300
> > "Michael S. Tsirkin" <mst@redhat.com> wrote:
> >
> >> On Fri, Sep 19, 2014 at 02:37:46PM +0200, Igor Mammedov wrote:
> >>> On Tue, 16 Sep 2014 18:39:15 +0800
> >>> zhanghailiang <zhang.zhanghailiang@huawei.com> 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"
> >>>>
> >>>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> >>>> ---
> >>>>   hw/mem/pc-dimm.c | 2 +-
> >>>>   1 file changed, 1 insertion(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> >>>> index 5bfc5b7..a800ea7 100644
> >>>> --- a/hw/mem/pc-dimm.c
> >>>> +++ b/hw/mem/pc-dimm.c
> >>>> @@ -252,7 +252,7 @@ static void pc_dimm_realize(DeviceState *dev, Error **errp)
> >>>>           error_setg(errp, "'" PC_DIMM_MEMDEV_PROP "' property is not set");
> >>>>           return;
> >>>>       }
> >>>> -    if (dimm->node >= nb_numa_nodes) {
> >>>> +    if ((nb_numa_nodes > 0) && (dimm->node >= nb_numa_nodes)) {
> >>>>           error_setg(errp, "'DIMM property " PC_DIMM_NODE_PROP " has value %"
> >>>>                      PRIu32 "' which exceeds the number of numa nodes: %d",
> >>>>                      dimm->node, nb_numa_nodes);
> >>>
> >>> Reviewed-By: Igor Mammedov <imammedo@redhat.com>
> >>
> >>
> >> I read:
> >>> Hmm, I have just tested this, and Yes, it didn't work for Windows guest.
> >>> Thanks for your kind reminder.;)
> >>
> >> So should I expect v2 which works with windows?
> > Hotplug wouldn't work with Windows without -numa (it's Windows limitation)
> > and more importantly pc-dimm shouldn't be limited only to NUMA configs
> > which this patch fixes.
> > This patch is fine and should go to stable as well.
> >
> 
> Agreed, maybe i should change the title and submit V2.;)
sure

> 
> > On top of this we could add automatic NUMA node creation when
> > memory hotplug is enabled if this Windows workaround is acceptable.
> >
> >
> > .
> >
> 
>