Re: [Qemu-discuss] Any one have successfully make window 7 guest in kvm use more than 2 cpus/cores?

[Tony Su]

  Aside from verifying/supporting the previous posts which state that a
Desktop OS like Win7 only supports 2 CPUs, I wonder why the effort to
even deploy on multiple CPU. Today's OS (all I know of) fully take
advantage of all physical CPUs no matter how many (or few) virtual
CPUs are configured. The only reason I can conceive  of to configure
multiple CPUs is to attempt to partition running processes on physical
CPUs (not virtual) which I highly doubt would be an objective running
any app on Win7 (or similar desktop).

On Wed, Jul 23, 2014 at 7:23 PM, Tony Su <address@hidden> wrote:
>  
> http://social.technet.microsoft.com/Forums/windows/en-US/970c999c-8ffc-4611-968c-7d0ceffbedd4/max-number-of-cpu-cores-that-windows-7-64-bit-will-recognize?forum=w7itprohardware
>
> Depending on your version of Windows 7, your license supports either
> one or two CPU and any number of cores.
>
> Tony
>
> On Wed, Jul 23, 2014 at 6:45 PM, Scott Zhang <address@hidden> wrote:
>> that is interesting. i use my opensuse 13.1 with i7 4cores.cpu and run win7
>> as guest. win7 show 4 cpus correctly. guess the problem with fedora kvm or
>> the xeon cpu. will try later to confirm
>>
>> On Jul 24, 2014 12:35 AM, "Jakob Bohm" <address@hidden> wrote:
>>>
>>> On 7/23/2014 6:22 PM, Sai Prajeeth wrote:
>>>>
>>>> Try setting sockets=6,cores=1? I had this issue when running Solaris as
>>>> guest. For some reason Solaris never detected any of the cores. It could
>>>> only detect the sockets.
>>>>
>>>>
>>> Unlikely to work.  Windows 7 (unlike the more expensive server licenses
>>> for the same kernel) enforces a license restriction of max 2 physical
>>> CPUs, each with unlimited cores (subject to the kernel design maximum
>>> of at least 32).
>>>
>>> But try looking at the command line of the running qemu process.  Does
>>> it actually specify 2 sockets with 4 cores each, or were the settings
>>> somehow mistranslated from libvirt XML to qemu command line?
>>>
>>> Also, if you are using a computer with more than 2 physical sockets,
>>> you may want to check if kvm passes through the physical or the command
>>> line CPU topology to the guest.
>>>
>>>> On Wed, Jul 23, 2014 at 9:38 PM, Scott Zhang <address@hidden
>>>> <mailto:address@hidden>> wrote:
>>>>
>>>>     __
>>>>     __
>>>>     Dear all:
>>>>         I have been trying this for whole afternoon and whole night. I
>>>>     have installed windows 7 as guest in kvm using virt-manager which
>>>>     use qemu. And after I alloc it 6 vcpus, I noticed win7 only see 2
>>>>     cpus in task manager. But in device manager, it shows 6 cpus. After
>>>>     google a lot, looks many people say they workaround this by setting
>>>>     the topology of CPU, which is technical correct.
>>>>         But when I try to set sockets=2,cores=4 and several vairable
>>>>     pairs. None is working. Win7 only see 2 at most. I am using fedora
>>>>     20 with kernel 3.15 and the default qemu.
>>>>         Can any one help?
>>>>     Thanks
>>>>     Regards
>>>>     2014-07-24
>>>>
>>>> ------------------------------------------------------------------------
>>>>     Scott Zhang
>>>>     __
>>>>
>>>>
>>>
>>>
>>> Enjoy
>>>
>>> Jakob
>>> --
>>> Jakob Bohm, CIO, Partner, WiseMo A/S.  http://www.wisemo.com
>>> Transformervej 29, 2730 Herlev, Denmark.  Direct +45 31 13 16 10
>>> This public discussion message is non-binding and may contain errors.
>>> WiseMo - Remote Service Management for PCs, Phones and Embedded
>>>
>>