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

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

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.;)

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