Re: [Qemu-devel] cpu hotplug and windows guest (win2012r2)

[Andrey Korolyov]

On Fri, Jan 9, 2015 at 4:35 PM, Andrey Korolyov <address@hidden> wrote:
> On Fri, Jan 9, 2015 at 1:26 PM, Alexandre DERUMIER <address@hidden> wrote:
>> Hi,
>>
>> I'm currently testing cpu hotplug with a windows 2012R2 standard guest,
>>
>> and I can't get it too work. (works fine with linux guest).
>>
>> host kernel : rhel7 3.10 kernel
>> qemu 2.2
>>
>>
>> qemu command line : -smp cpus=1,sockets=2,cores=1,maxcpus=2
>>
>> Started with 1cpu, topogoly is 2sockets with 1cores.
>>
>>
>> Then
>>
>> qmp# cpu-add 1
>>
>>
>> I can see a new cpu is windows device manager, and event log in the device 
>> said that it's online.
>>
>> So it should be ok, but.
>>
>> I can't see new processor in taskmanager or perfmon. (I had tried to 
>> relaunch them to be sure.).
>>
>>
>> So, it is a windows bug ? Does I need to do something else ?
>>
>
> Did you populated appropriate topology in arguments? As far as I can
> remember from pre-1.1 era CPU hotplug not worked with windows, so it
> should be neither lack of configured NUMA or a simply OS-specific
> issue.

Just to let anyone know that it works well:

http://xdel.ru/downloads/windows-hotplugged-cpu.png

Topology is a bit rotten (I have two sockets with single CPU in each)
and I *need* to specify non-zero amount of memory for each numa node
to be seen, if each CPU belongs to different node for example but
everything else is just fine.